Enforce non-nullability in more cases during JSON parse (#367)

This reverts commit 8d275f0047.

CHANGELOG.md

@@ -1,5 +1,10 @@
 Notable changes are recorded here.
 
+# WoofWare.Myriad.Plugins 5.0.1
+
+We now enforce non-nullability on more types during JSON parse.
+We have always expected you to consume nullable types wrapped in an `option`, but now we enforce this in more cases by throwing `ArgumentNullException`.
+
 # WoofWare.Myriad.Plugins 3.0.1
 
 Semantics of `HttpClient`'s URI component composition changed:

ConsumePlugin/Args.fs

@@ -235,9 +235,3 @@ type FlagsIntoPositionalArgs' =
         [<PositionalArgs false>]
         DontGrabEverything : string list
     }
-
-[<ArgParser true>]
-type PassThru =
-    {
-        A : ParentRecordChildPos
-    }

ConsumePlugin/ArgsWithUnions.fs

@@ -1,35 +0,0 @@
-namespace ConsumePlugin.ArgsWithUnions
-
-open System
-open System.IO
-open WoofWare.Myriad.Plugins
-
-type BasicNoPositionals =
-    {
-        Foo : int
-        Bar : string
-        Baz : bool
-        Rest : int list
-    }
-
-type UsernamePasswordAuth =
-    {
-        Username : string
-        Password : string
-    }
-
-type TokenAuth =
-    {
-        Token : string
-    }
-
-type AuthOptions =
-    | UsernamePassword of UsernamePasswordAuth
-    | Token of TokenAuth
-
-[<ArgParser>]
-type DoTheThing =
-    {
-        Basics : BasicNoPositionals
-        Auth : AuthOptions
-    }

ConsumePlugin/ConsumePlugin.fsproj

@@ -12,7 +12,6 @@
   <ItemGroup>
     <None Include="myriad.toml"/>
     <Compile Include="AssemblyInfo.fs" />
-    <!--
     <Compile Include="RecordFile.fs"/>
     <Compile Include="GeneratedRecord.fs">
       <MyriadFile>RecordFile.fs</MyriadFile>
@@ -67,16 +66,10 @@
     <Compile Include="ListCata.fs">
       <MyriadFile>List.fs</MyriadFile>
     </Compile>
-    -->
     <Compile Include="Args.fs" />
     <Compile Include="GeneratedArgs.fs">
       <MyriadFile>Args.fs</MyriadFile>
     </Compile>
-    <Compile Include="ArgsWithUnions.fs" />
-    <Compile Include="GeneratedArgsWithUnions.fs">
-      <MyriadFile>ArgsWithUnions.fs</MyriadFile>
-    </Compile>
-    <!--
     <None Include="swagger-gitea.json" />
     <Compile Include="GeneratedSwaggerGitea.fs">
       <MyriadFile>swagger-gitea.json</MyriadFile>
@@ -88,7 +81,6 @@
     <Compile Include="Generated2SwaggerGitea.fs">
       <MyriadFile>GeneratedSwaggerGitea.fs</MyriadFile>
     </Compile>
-    -->
   </ItemGroup>
 
   <ItemGroup>

ConsumePlugin/GeneratedArgsWithUnions.fs

@@ -1,686 +0,0 @@
-//------------------------------------------------------------------------------
-//        This code was generated by myriad.
-//        Changes to this file will be lost when the code is regenerated.
-//------------------------------------------------------------------------------
-
-
-
-
-
-
-namespace ArgParserHelpers
-
-/// Helper types for arg parsing
-module internal ArgParseHelpers_ConsumePlugin_ArgsWithUnions =
-    open System
-    open System.IO
-    open WoofWare.Myriad.Plugins
-    open ConsumePlugin.ArgsWithUnions
-
-    /// A partially-parsed BasicNoPositionals.
-    type internal BasicNoPositionals_InProgress =
-        {
-            mutable Bar : string option
-            mutable Baz : bool option
-            mutable Foo : int option
-            mutable Rest : ResizeArray<int>
-        }
-
-        /// Freeze this in-progress type. On success, returns the frozen type and the arg (if any) which consumed the input positional args.
-        member this.Assemble_
-            (getEnvironmentVariable : string -> string)
-            (positionals : Choice<string * int, string * int> list)
-            : Result<BasicNoPositionals * string option, string list>
-            =
-            let errors = ResizeArray<string> ()
-            let positionalConsumers = ResizeArray<string> ()
-            let outOfPlacePositionals : ResizeArray<string> = ResizeArray ()
-
-            let arg0 : int =
-                match this.Foo with
-                | Some result -> result
-                | None ->
-                    errors.Add (sprintf "Required argument '--%s' received no value" "foo")
-                    Unchecked.defaultof<_>
-
-            let arg1 : string =
-                match this.Bar with
-                | Some result -> result
-                | None ->
-                    errors.Add (sprintf "Required argument '--%s' received no value" "bar")
-                    Unchecked.defaultof<_>
-
-            let arg2 : bool =
-                match this.Baz with
-                | Some result -> result
-                | None ->
-                    errors.Add (sprintf "Required argument '--%s' received no value" "baz")
-                    Unchecked.defaultof<_>
-
-            let arg3 : int list = this.Rest |> Seq.toList
-
-            if positionalConsumers.Count <= 1 then
-                if outOfPlacePositionals.Count > 0 then
-                    outOfPlacePositionals
-                    |> String.concat " "
-                    |> (fun x ->
-                        if 0 = outOfPlacePositionals.Count then
-                            "Unmatched args which look like they are meant to be flags. " + x
-                        else
-                            sprintf
-                                "Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `%s=` syntax, or place them after a trailing `--`. %s"
-                                positionalConsumers.[0]
-                                x
-                    )
-                    |> errors.Add
-                else
-                    ()
-
-                if errors.Count = 0 then
-                    Ok (
-                        {
-                            Foo = arg0
-                            Bar = arg1
-                            Baz = arg2
-                            Rest = arg3
-                        },
-                        Seq.tryExactlyOne positionalConsumers
-                    )
-                else
-                    errors |> Seq.toList |> Error
-            else
-                ("Multiple parsers consumed positional args; this is an error in the application, not an error by the user: "
-                 + String.concat ", " positionalConsumers)
-                |> List.singleton
-                |> Error
-
-        static member _Empty () : BasicNoPositionals_InProgress =
-            {
-                Bar = None
-                Baz = None
-                Foo = None
-                Rest = ResizeArray ()
-            }
-
-        /// Processes the key-value pair, returning Error if no key was matched.
-        /// If the key is an arg which can have arity 1, but throws when consuming that arg, we return Error(<the message>).
-        /// This can nevertheless be a successful parse, e.g. when the key may have arity 0.
-        member this.ProcessKeyValueSelf_
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            if System.String.Equals (key, sprintf "--%s" "rest", System.StringComparison.OrdinalIgnoreCase) then
-                value |> (fun x -> System.Int32.Parse x) |> (fun x -> x) |> this.Rest.Add
-                () |> Ok
-            else if System.String.Equals (key, sprintf "--%s" "foo", System.StringComparison.OrdinalIgnoreCase) then
-                match this.Foo with
-                | Some x ->
-                    sprintf
-                        "Argument '%s' was supplied multiple times: %s and %s"
-                        (sprintf "--%s" "foo")
-                        (x.ToString ())
-                        (value.ToString ())
-                    |> errors_.Add
-
-                    Ok ()
-                | None ->
-                    try
-                        this.Foo <- value |> (fun x -> System.Int32.Parse x) |> Some
-                        Ok ()
-                    with _ as exc ->
-                        exc.Message |> Some |> Error
-            else if System.String.Equals (key, sprintf "--%s" "baz", System.StringComparison.OrdinalIgnoreCase) then
-                match this.Baz with
-                | Some x ->
-                    sprintf
-                        "Argument '%s' was supplied multiple times: %s and %s"
-                        (sprintf "--%s" "baz")
-                        (x.ToString ())
-                        (value.ToString ())
-                    |> errors_.Add
-
-                    Ok ()
-                | None ->
-                    try
-                        this.Baz <- value |> (fun x -> System.Boolean.Parse x) |> Some
-                        Ok ()
-                    with _ as exc ->
-                        exc.Message |> Some |> Error
-            else if System.String.Equals (key, sprintf "--%s" "bar", System.StringComparison.OrdinalIgnoreCase) then
-                match this.Bar with
-                | Some x ->
-                    sprintf
-                        "Argument '%s' was supplied multiple times: %s and %s"
-                        (sprintf "--%s" "bar")
-                        (x.ToString ())
-                        (value.ToString ())
-                    |> errors_.Add
-
-                    Ok ()
-                | None ->
-                    try
-                        this.Bar <- value |> (fun x -> x) |> Some
-                        Ok ()
-                    with _ as exc ->
-                        exc.Message |> Some |> Error
-            else
-                Error None
-
-        member this.ProcessKeyValue
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            match this.ProcessKeyValueSelf_ argNum_ errors_ key value with
-            | Ok () -> Ok ()
-            | Error None -> Error None
-            | Error (Some errorFromLeaf) -> Error (Some errorFromLeaf)
-
-        /// Returns false if we didn't set a value.
-        member this.SetFlagValue_ (errors_ : ResizeArray<string>) (key : string) : bool =
-            if System.String.Equals (key, sprintf "--%s" "baz", System.StringComparison.OrdinalIgnoreCase) then
-                match this.Baz with
-                | Some _ ->
-                    sprintf "Flag '%s' was supplied multiple times" (sprintf "--%s" "baz")
-                    |> errors_.Add
-
-                    true
-                | None ->
-                    this.Baz <- true |> Some
-                    true
-            else
-                false
-
-        /// Compute help text for this parser, optionally noting the given prefix on each argument and indenting each line by this many spaces.
-        static member HelpText_ (prefix : string option) (indent : int) : string = failwith "TODO"
-
-    /// A partially-parsed UsernamePasswordAuth.
-    type internal UsernamePasswordAuth_InProgress =
-        {
-            mutable Password : string option
-            mutable Username : string option
-        }
-
-        /// Freeze this in-progress type. On success, returns the frozen type and the arg (if any) which consumed the input positional args.
-        member this.Assemble_
-            (getEnvironmentVariable : string -> string)
-            (positionals : Choice<string * int, string * int> list)
-            : Result<UsernamePasswordAuth * string option, string list>
-            =
-            let errors = ResizeArray<string> ()
-            let positionalConsumers = ResizeArray<string> ()
-            let outOfPlacePositionals : ResizeArray<string> = ResizeArray ()
-
-            let arg0 : string =
-                match this.Username with
-                | Some result -> result
-                | None ->
-                    errors.Add (sprintf "Required argument '--%s' received no value" "username")
-                    Unchecked.defaultof<_>
-
-            let arg1 : string =
-                match this.Password with
-                | Some result -> result
-                | None ->
-                    errors.Add (sprintf "Required argument '--%s' received no value" "password")
-                    Unchecked.defaultof<_>
-
-            if positionalConsumers.Count <= 1 then
-                if outOfPlacePositionals.Count > 0 then
-                    outOfPlacePositionals
-                    |> String.concat " "
-                    |> (fun x ->
-                        if 0 = outOfPlacePositionals.Count then
-                            "Unmatched args which look like they are meant to be flags. " + x
-                        else
-                            sprintf
-                                "Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `%s=` syntax, or place them after a trailing `--`. %s"
-                                positionalConsumers.[0]
-                                x
-                    )
-                    |> errors.Add
-                else
-                    ()
-
-                if errors.Count = 0 then
-                    Ok (
-                        {
-                            Username = arg0
-                            Password = arg1
-                        },
-                        Seq.tryExactlyOne positionalConsumers
-                    )
-                else
-                    errors |> Seq.toList |> Error
-            else
-                ("Multiple parsers consumed positional args; this is an error in the application, not an error by the user: "
-                 + String.concat ", " positionalConsumers)
-                |> List.singleton
-                |> Error
-
-        static member _Empty () : UsernamePasswordAuth_InProgress =
-            {
-                Password = None
-                Username = None
-            }
-
-        /// Processes the key-value pair, returning Error if no key was matched.
-        /// If the key is an arg which can have arity 1, but throws when consuming that arg, we return Error(<the message>).
-        /// This can nevertheless be a successful parse, e.g. when the key may have arity 0.
-        member this.ProcessKeyValueSelf_
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            if System.String.Equals (key, sprintf "--%s" "username", System.StringComparison.OrdinalIgnoreCase) then
-                match this.Username with
-                | Some x ->
-                    sprintf
-                        "Argument '%s' was supplied multiple times: %s and %s"
-                        (sprintf "--%s" "username")
-                        (x.ToString ())
-                        (value.ToString ())
-                    |> errors_.Add
-
-                    Ok ()
-                | None ->
-                    try
-                        this.Username <- value |> (fun x -> x) |> Some
-                        Ok ()
-                    with _ as exc ->
-                        exc.Message |> Some |> Error
-            else if
-                System.String.Equals (key, sprintf "--%s" "password", System.StringComparison.OrdinalIgnoreCase)
-            then
-                match this.Password with
-                | Some x ->
-                    sprintf
-                        "Argument '%s' was supplied multiple times: %s and %s"
-                        (sprintf "--%s" "password")
-                        (x.ToString ())
-                        (value.ToString ())
-                    |> errors_.Add
-
-                    Ok ()
-                | None ->
-                    try
-                        this.Password <- value |> (fun x -> x) |> Some
-                        Ok ()
-                    with _ as exc ->
-                        exc.Message |> Some |> Error
-            else
-                Error None
-
-        member this.ProcessKeyValue
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            match this.ProcessKeyValueSelf_ argNum_ errors_ key value with
-            | Ok () -> Ok ()
-            | Error None -> Error None
-            | Error (Some errorFromLeaf) -> Error (Some errorFromLeaf)
-
-        /// Returns false if we didn't set a value.
-        member this.SetFlagValue_ (errors_ : ResizeArray<string>) (key : string) : bool = false
-        /// Compute help text for this parser, optionally noting the given prefix on each argument and indenting each line by this many spaces.
-        static member HelpText_ (prefix : string option) (indent : int) : string = failwith "TODO"
-
-    /// A partially-parsed TokenAuth.
-    type internal TokenAuth_InProgress =
-        {
-            mutable Token : string option
-        }
-
-        /// Freeze this in-progress type. On success, returns the frozen type and the arg (if any) which consumed the input positional args.
-        member this.Assemble_
-            (getEnvironmentVariable : string -> string)
-            (positionals : Choice<string * int, string * int> list)
-            : Result<TokenAuth * string option, string list>
-            =
-            let errors = ResizeArray<string> ()
-            let positionalConsumers = ResizeArray<string> ()
-            let outOfPlacePositionals : ResizeArray<string> = ResizeArray ()
-
-            let arg0 : string =
-                match this.Token with
-                | Some result -> result
-                | None ->
-                    errors.Add (sprintf "Required argument '--%s' received no value" "token")
-                    Unchecked.defaultof<_>
-
-            if positionalConsumers.Count <= 1 then
-                if outOfPlacePositionals.Count > 0 then
-                    outOfPlacePositionals
-                    |> String.concat " "
-                    |> (fun x ->
-                        if 0 = outOfPlacePositionals.Count then
-                            "Unmatched args which look like they are meant to be flags. " + x
-                        else
-                            sprintf
-                                "Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `%s=` syntax, or place them after a trailing `--`. %s"
-                                positionalConsumers.[0]
-                                x
-                    )
-                    |> errors.Add
-                else
-                    ()
-
-                if errors.Count = 0 then
-                    Ok (
-                        {
-                            Token = arg0
-                        },
-                        Seq.tryExactlyOne positionalConsumers
-                    )
-                else
-                    errors |> Seq.toList |> Error
-            else
-                ("Multiple parsers consumed positional args; this is an error in the application, not an error by the user: "
-                 + String.concat ", " positionalConsumers)
-                |> List.singleton
-                |> Error
-
-        static member _Empty () : TokenAuth_InProgress =
-            {
-                Token = None
-            }
-
-        /// Processes the key-value pair, returning Error if no key was matched.
-        /// If the key is an arg which can have arity 1, but throws when consuming that arg, we return Error(<the message>).
-        /// This can nevertheless be a successful parse, e.g. when the key may have arity 0.
-        member this.ProcessKeyValueSelf_
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            if System.String.Equals (key, sprintf "--%s" "token", System.StringComparison.OrdinalIgnoreCase) then
-                match this.Token with
-                | Some x ->
-                    sprintf
-                        "Argument '%s' was supplied multiple times: %s and %s"
-                        (sprintf "--%s" "token")
-                        (x.ToString ())
-                        (value.ToString ())
-                    |> errors_.Add
-
-                    Ok ()
-                | None ->
-                    try
-                        this.Token <- value |> (fun x -> x) |> Some
-                        Ok ()
-                    with _ as exc ->
-                        exc.Message |> Some |> Error
-            else
-                Error None
-
-        member this.ProcessKeyValue
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            match this.ProcessKeyValueSelf_ argNum_ errors_ key value with
-            | Ok () -> Ok ()
-            | Error None -> Error None
-            | Error (Some errorFromLeaf) -> Error (Some errorFromLeaf)
-
-        /// Returns false if we didn't set a value.
-        member this.SetFlagValue_ (errors_ : ResizeArray<string>) (key : string) : bool = false
-        /// Compute help text for this parser, optionally noting the given prefix on each argument and indenting each line by this many spaces.
-        static member HelpText_ (prefix : string option) (indent : int) : string = failwith "TODO"
-
-    /// A partially-parsed AuthOptions.
-    type internal AuthOptions_InProgress =
-        {
-            Token : TokenAuth_InProgress
-            UsernamePassword : UsernamePasswordAuth_InProgress
-        }
-
-        /// Freeze this in-progress type. On success, returns the frozen type and the arg (if any) which consumed the input positional args.
-        member this.Assemble_
-            (getEnvironmentVariable : string -> string)
-            (positionals : Choice<string * int, string * int> list)
-            : Result<AuthOptions * string option, string list>
-            =
-            failwith "TODO"
-
-        static member _Empty () : AuthOptions_InProgress =
-            {
-                Token = TokenAuth_InProgress._Empty ()
-                UsernamePassword = UsernamePasswordAuth_InProgress._Empty ()
-            }
-
-        /// Compute help text for this parser, optionally noting the given prefix on each argument and indenting each line by this many spaces.
-        static member HelpText_ (prefix : string option) (indent : int) : string = failwith "TODO"
-
-    /// A partially-parsed DoTheThing.
-    type internal DoTheThing_InProgress =
-        {
-            mutable Auth : AuthOptions_InProgress
-            mutable Basics : BasicNoPositionals_InProgress
-        }
-
-        /// Freeze this in-progress type. On success, returns the frozen type and the arg (if any) which consumed the input positional args.
-        member this.Assemble_
-            (getEnvironmentVariable : string -> string)
-            (positionals : Choice<string * int, string * int> list)
-            : Result<DoTheThing * string option, string list>
-            =
-            let errors = ResizeArray<string> ()
-            let positionalConsumers = ResizeArray<string> ()
-            let outOfPlacePositionals : ResizeArray<string> = ResizeArray ()
-
-            let arg0 : BasicNoPositionals =
-                match this.Basics.Assemble_ getEnvironmentVariable positionals with
-                | Ok (result, consumedPositional) ->
-                    match consumedPositional with
-                    | None -> ()
-                    | Some positionalConsumer -> positionalConsumers.Add positionalConsumer
-
-                    result
-                | Error err ->
-                    errors.AddRange err
-                    Unchecked.defaultof<_>
-
-            let arg1 : AuthOptions =
-                match this.Auth.Assemble_ getEnvironmentVariable positionals with
-                | Ok (result, consumedPositional) ->
-                    match consumedPositional with
-                    | None -> ()
-                    | Some positionalConsumer -> positionalConsumers.Add positionalConsumer
-
-                    result
-                | Error err ->
-                    errors.AddRange err
-                    Unchecked.defaultof<_>
-
-            if positionalConsumers.Count <= 1 then
-                if outOfPlacePositionals.Count > 0 then
-                    outOfPlacePositionals
-                    |> String.concat " "
-                    |> (fun x ->
-                        if 0 = outOfPlacePositionals.Count then
-                            "Unmatched args which look like they are meant to be flags. " + x
-                        else
-                            sprintf
-                                "Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `%s=` syntax, or place them after a trailing `--`. %s"
-                                positionalConsumers.[0]
-                                x
-                    )
-                    |> errors.Add
-                else
-                    ()
-
-                if errors.Count = 0 then
-                    Ok (
-                        {
-                            Basics = arg0
-                            Auth = arg1
-                        },
-                        Seq.tryExactlyOne positionalConsumers
-                    )
-                else
-                    errors |> Seq.toList |> Error
-            else
-                ("Multiple parsers consumed positional args; this is an error in the application, not an error by the user: "
-                 + String.concat ", " positionalConsumers)
-                |> List.singleton
-                |> Error
-
-        static member _Empty () : DoTheThing_InProgress =
-            {
-                Basics = BasicNoPositionals_InProgress._Empty ()
-                Auth = AuthOptions_InProgress._Empty ()
-            }
-
-        /// Passes the key-value pair to any child records, returning Error if no key was matched.
-        /// If the key is an arg which can have arity 1, but throws when consuming that arg, we return Error(<the message>).
-        /// This can nevertheless be a successful parse, e.g. when the key may have arity 0.
-        member this.ProcessKeyValueRecord_
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            let errors : ResizeArray<string> = ResizeArray ()
-
-            match this.Basics.ProcessKeyValue argNum_ errors_ key value with
-            | Ok () -> Ok ()
-            | Error e -> Error None
-
-        member this.ProcessKeyValue
-            (argNum_ : int)
-            (errors_ : ResizeArray<string>)
-            (key : string)
-            (value : string)
-            : Result<unit, string option>
-            =
-            match this.ProcessKeyValueRecord_ argNum_ errors_ key value with
-            | Ok () -> Ok ()
-            | Error errorFromRecord -> Error errorFromRecord
-
-        /// Returns false if we didn't set a value.
-        member this.SetFlagValue_ (errors_ : ResizeArray<string>) (key : string) : bool = false
-        /// Compute help text for this parser, optionally noting the given prefix on each argument and indenting each line by this many spaces.
-        static member HelpText_ (prefix : string option) (indent : int) : string = failwith "TODO"
-namespace ConsumePlugin.ArgsWithUnions
-
-open ArgParserHelpers
-open System
-open System.IO
-open WoofWare.Myriad.Plugins
-
-/// Methods to parse arguments for the type DoTheThing
-[<RequireQualifiedAccess ; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
-module DoTheThing =
-    type internal ParseState_DoTheThing =
-        /// Ready to consume a key or positional arg
-        | AwaitingKey
-        /// Waiting to receive a value for the key we've already consumed
-        | AwaitingValue of key : string
-
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : DoTheThing =
-        let inProgress =
-            ArgParseHelpers_ConsumePlugin_ArgsWithUnions.DoTheThing_InProgress._Empty ()
-
-        let positionals : ResizeArray<Choice<string * int, string * int>> = ResizeArray ()
-        let errors_ = ResizeArray ()
-
-        let rec go (argNum_ : int) (state : ParseState_DoTheThing) (args : string list) =
-            match args with
-            | [] ->
-                match state with
-                | ParseState_DoTheThing.AwaitingKey -> ()
-                | ParseState_DoTheThing.AwaitingValue key ->
-                    if inProgress.SetFlagValue_ errors_ key then
-                        ()
-                    else
-                        sprintf
-                            "Trailing argument %s had no value. Use a double-dash to separate positional args from key-value args."
-                            key
-                        |> errors_.Add
-            | "--" :: rest -> positionals.AddRange (rest |> Seq.map (fun x -> (x, argNum_ + 1)) |> Seq.map Choice2Of2)
-            | arg :: args ->
-                match state with
-                | ParseState_DoTheThing.AwaitingKey ->
-                    if arg.StartsWith ("--", System.StringComparison.Ordinal) then
-                        if arg = "--help" then
-                            "TODO" |> failwithf "Help text requested.\n%s"
-                        else
-                            let equals = arg.IndexOf (char 61)
-
-                            if equals < 0 then
-                                go (argNum_ + 1) (ParseState_DoTheThing.AwaitingValue arg) args
-                            else
-                                let key = arg.[0 .. equals - 1]
-                                let value = arg.[equals + 1 ..]
-
-                                match inProgress.ProcessKeyValue argNum_ errors_ key value with
-                                | Ok () -> go (argNum_ + 1) ParseState_DoTheThing.AwaitingKey args
-                                | Error x ->
-                                    match x with
-                                    | None ->
-                                        positionals.Add (Choice1Of2 (arg, argNum_))
-                                        go (argNum_ + 1) ParseState_DoTheThing.AwaitingKey args
-                                    | Some msg ->
-                                        sprintf "%s (at arg %s)" msg arg |> errors_.Add
-                                        go (argNum_ + 1) ParseState_DoTheThing.AwaitingKey args
-                    else
-                        (arg, argNum_) |> Choice1Of2 |> positionals.Add
-                        go (argNum_ + 1) ParseState_DoTheThing.AwaitingKey args
-                | ParseState_DoTheThing.AwaitingValue key ->
-                    match inProgress.ProcessKeyValue argNum_ errors_ key arg with
-                    | Ok () -> go argNum_ ParseState_DoTheThing.AwaitingKey args
-                    | Error exc ->
-                        if inProgress.SetFlagValue_ errors_ key then
-                            go argNum_ ParseState_DoTheThing.AwaitingKey (arg :: args)
-                        else
-                            (key, argNum_) |> Choice1Of2 |> positionals.Add
-                            go (argNum_ + 1) ParseState_DoTheThing.AwaitingKey (arg :: args)
-
-        go 0 ParseState_DoTheThing.AwaitingKey args
-
-        if 0 = errors_.Count then
-            ()
-        else
-            errors_
-            |> String.concat System.Environment.NewLine
-            |> (fun x -> "Errors during parse!\n" + x)
-            |> failwith
-
-        match inProgress.Assemble_ getEnvironmentVariable (positionals |> Seq.toList) with
-        | Ok (result, posConsumer) ->
-            if positionals.Count > 0 && posConsumer.IsNone then
-                positionals
-                |> Seq.map (fun choiceValue ->
-                    match choiceValue with
-                    | Choice1Of2 (arg, _) -> arg
-                    | Choice2Of2 (arg, _) -> arg
-                )
-                |> String.concat " "
-                |> sprintf "Parse error: The following arguments were not consumed: %s"
-                |> failwith
-            else
-                result
-        | Error e ->
-            e
-            |> String.concat System.Environment.NewLine
-            |> (fun x -> "Errors during parse!\n" + x)
-            |> failwith
-
-    let parse (args : string list) : DoTheThing =
-        parse' System.Environment.GetEnvironmentVariable args

ConsumePlugin/GeneratedJson.fs

@@ -71,7 +71,11 @@ module JsonRecordType =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Int32> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.Int32> ())
+            )
             |> Array.ofSeq
 
         let arg_4 =
@@ -84,7 +88,11 @@ module JsonRecordType =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.String> ())
+            )
             |> Array.ofSeq
 
         let arg_3 =
@@ -109,7 +117,11 @@ module JsonRecordType =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Int32> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.Int32> ())
+            )
             |> List.ofSeq
 
         let arg_1 =

ConsumePlugin/GeneratedPureGymDto.fs

@@ -60,7 +60,11 @@ module GymOpeningHours =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.String> ())
+            )
             |> List.ofSeq
 
         let arg_0 =
@@ -1038,7 +1042,11 @@ module Sessions =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> Visit.jsonParse elt)
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> Visit.jsonParse elt)
+            )
             |> List.ofSeq
 
         let arg_0 =

ConsumePlugin/GeneratedRestClient.fs

@@ -48,7 +48,14 @@ module PureGymApi =
                         System.Text.Json.Nodes.JsonNode.ParseAsync (responseStream, cancellationToken = ct)
                         |> Async.AwaitTask
 
-                    return jsonNode.AsArray () |> Seq.map (fun elt -> Gym.jsonParse elt) |> List.ofSeq
+                    return
+                        jsonNode.AsArray ()
+                        |> Seq.map (fun elt ->
+                            (match elt with
+                             | null -> raise (System.ArgumentNullException ())
+                             | elt -> Gym.jsonParse elt)
+                        )
+                        |> List.ofSeq
                 }
                 |> (fun a -> Async.StartAsTask (a, ?cancellationToken = ct))
 

ConsumePlugin/GeneratedSerde.fs

@@ -408,7 +408,11 @@ module InnerTypeWithBothJsonParseExtension =
 
                     let value =
                         (kvp.Value).AsArray ()
-                        |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Char> ())
+                        |> Seq.map (fun elt ->
+                            (match elt with
+                             | null -> raise (System.ArgumentNullException ())
+                             | elt -> elt.AsValue().GetValue<System.Char> ())
+                        )
                         |> List.ofSeq
 
                     key, value
@@ -676,7 +680,11 @@ module JsonRecordTypeWithBothJsonParseExtension =
                      )
                  | v -> v)
                     .AsArray ()
-                |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Int32> ())
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null -> raise (System.ArgumentNullException ())
+                     | elt -> elt.AsValue().GetValue<System.Int32> ())
+                )
                 |> Array.ofSeq
 
             let arg_4 =
@@ -689,7 +697,11 @@ module JsonRecordTypeWithBothJsonParseExtension =
                      )
                  | v -> v)
                     .AsArray ()
-                |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null -> raise (System.ArgumentNullException ())
+                     | elt -> elt.AsValue().GetValue<System.String> ())
+                )
                 |> Array.ofSeq
 
             let arg_3 =
@@ -714,7 +726,11 @@ module JsonRecordTypeWithBothJsonParseExtension =
                      )
                  | v -> v)
                     .AsArray ()
-                |> Seq.map (fun elt -> elt.AsValue().GetValue<System.Int32> ())
+                |> Seq.map (fun elt ->
+                    (match elt with
+                     | null -> raise (System.ArgumentNullException ())
+                     | elt -> elt.AsValue().GetValue<System.Int32> ())
+                )
                 |> List.ofSeq
 
             let arg_1 =

ConsumePlugin/GeneratedVault.fs

@@ -94,7 +94,11 @@ module JwtVaultAuthResponse =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.String> ())
+            )
             |> List.ofSeq
 
         let arg_3 =
@@ -107,7 +111,11 @@ module JwtVaultAuthResponse =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.String> ())
+            )
             |> List.ofSeq
 
         let arg_2 =
@@ -120,7 +128,11 @@ module JwtVaultAuthResponse =
                  )
              | v -> v)
                 .AsArray ()
-            |> Seq.map (fun elt -> elt.AsValue().GetValue<System.String> ())
+            |> Seq.map (fun elt ->
+                (match elt with
+                 | null -> raise (System.ArgumentNullException ())
+                 | elt -> elt.AsValue().GetValue<System.String> ())
+            )
             |> List.ofSeq
 
         let arg_1 =

Playground/Domain.fs

@@ -1,47 +0,0 @@
-namespace Playground
-
-open System
-open WoofWare.Myriad.Plugins
-
-[<ArgParser>]
-type SubMode1 =
-    {
-        Info1 : int
-        Info2 : string
-        Rest : string list
-    }
-
-[<ArgParser>]
-type SubMode2 =
-    {
-        Info1 : int
-        Info2 : string
-        Rest : int list
-    }
-
-[<ArgParser>]
-type Mode1 =
-    {
-        Things : SubMode1
-        Whatnot : int
-    }
-
-[<ArgParser>]
-type Mode2 =
-    {
-        Things : SubMode2
-        Whatnot : DateTime
-    }
-
-[<ArgParser>]
-type Modes =
-    | Mode1 of Mode1
-    | Mode2 of Mode2
-
-[<ArgParser>]
-type Args =
-    {
-        WhatToDo : Modes
-        [<PositionalArgs>]
-        OtherArgs : string list
-    }

Playground/Library.fs

@@ -1,563 +0,0 @@
-//------------------------------------------------------------------------------
-//        This code was generated by myriad.
-//        Changes to this file will be lost when the code is regenerated.
-//------------------------------------------------------------------------------
-
-namespace Playground // Assuming a namespace
-
-open System
-open System.IO
-open WoofWare.Myriad.Plugins // Assuming attributes are here
-
-// Assume original type definitions are accessible here
-// [<ArgParser>] type SubMode1 = { Info1 : int; Info2 : string; Rest : string list }
-// [<ArgParser>] type SubMode2 = { Info1 : int; Info2 : string; Rest : int list }
-// [<ArgParser>] type Mode1 = { Things : SubMode1; Whatnot : int }
-// [<ArgParser>] type Mode2 = { Things : SubMode2; Whatnot : DateTime }
-// [<ArgParser>] type Modes = | Mode1 of Mode1 | Mode2 of Mode2
-// [<ArgParser>] type Args = { WhatToDo : Modes; [<PositionalArgs>] OtherArgs : string list }
-
-
-/// Methods to parse arguments for the type Args
-[<RequireQualifiedAccess ; CompilationRepresentation(CompilationRepresentationFlags.ModuleSuffix)>]
-module Args =
-
-    //--------------------------------------------------------------------------
-    // Internal state definitions (Non-Flattened with combined Assemble/Validate)
-    //--------------------------------------------------------------------------
-
-    /// State representing the parse progress for SubMode1 record
-    type private State_SubMode1 =
-        {
-            mutable Info1 : int option
-            mutable Info2 : string option
-            Rest : ResizeArray<string> // Corresponds to --rest
-        }
-
-        static member Create () =
-            {
-                Info1 = None
-                Info2 = None
-                Rest = ResizeArray ()
-            }
-
-        /// Check completeness and assemble the SubMode1 record from state.
-        member this.Assemble () : Result<SubMode1, string list> =
-            let errors = ResizeArray<string> ()
-            let mutable complete = true
-
-            if this.Info1.IsNone then
-                complete <- false
-                errors.Add ("Argument '--info1' is required.")
-
-            if this.Info2.IsNone then
-                complete <- false
-                errors.Add ("Argument '--info2' is required.")
-            // Rest is list, always 'complete'
-
-            if complete then
-                Ok
-                    {
-                        Info1 = this.Info1.Value
-                        Info2 = this.Info2.Value
-                        Rest = this.Rest |> Seq.toList
-                    }
-            else
-                Error (errors |> Seq.toList)
-
-    /// State representing the parse progress for SubMode2 record
-    type private State_SubMode2 =
-        {
-            mutable Info1 : int option
-            mutable Info2 : string option
-            Rest : ResizeArray<int> // Corresponds to --rest
-        }
-
-        static member Create () =
-            {
-                Info1 = None
-                Info2 = None
-                Rest = ResizeArray ()
-            }
-
-        /// Check completeness and assemble the SubMode2 record from state.
-        member this.Assemble () : Result<SubMode2, string list> =
-            let errors = ResizeArray<string> ()
-
-            if this.Info1.IsNone then
-                errors.Add ("Argument '--info1' is required.")
-
-            if this.Info2.IsNone then
-                errors.Add ("Argument '--info2' is required.")
-            // Rest is list, always 'complete'
-
-            if errors.Count = 0 then
-                Ok
-                    {
-                        Info1 = this.Info1.Value
-                        Info2 = this.Info2.Value
-                        Rest = this.Rest |> Seq.toList
-                    }
-            else
-                Error (errors |> Seq.toList)
-
-
-    /// State representing the parse progress for Mode1 record (references SubMode1 state)
-    type private State_Mode1 =
-        {
-            ThingsState : State_SubMode1 // Holds state for the nested record
-            mutable Whatnot : int option
-        }
-
-        static member Create () =
-            {
-                ThingsState = State_SubMode1.Create ()
-                Whatnot = None
-            }
-
-        /// Check completeness and assemble the Mode1 record from state (including nested).
-        member this.Assemble () : Result<Mode1, string list> =
-            let errors = ResizeArray<string> ()
-
-            // Check direct fields
-            if this.Whatnot.IsNone then
-                errors.Add ("Argument '--whatnot' is required for Mode1.")
-
-            // Assemble nested state (which includes its own validation)
-            let thingsResult = this.ThingsState.Assemble ()
-            let mutable thingsValue = None
-
-            match thingsResult with
-            | Ok v -> thingsValue <- Some v
-            | Error nestedErrors -> errors.AddRange (nestedErrors |> List.map (sprintf "Things: %s")) // Add context
-
-            if errors.Count = 0 then
-                Ok
-                    {
-                        Things = thingsValue.Value
-                        Whatnot = this.Whatnot.Value
-                    }
-            else
-                Error (errors |> Seq.toList)
-
-
-    /// State representing the parse progress for Mode2 record (references SubMode2 state)
-    type private State_Mode2 =
-        {
-            ThingsState : State_SubMode2 // Holds state for the nested record
-            mutable Whatnot : DateTime option
-        }
-
-        static member Create () =
-            {
-                ThingsState = State_SubMode2.Create ()
-                Whatnot = None
-            }
-
-        /// Check completeness and assemble the Mode2 record from state (including nested).
-        member this.Assemble () : Result<Mode2, string list> =
-            let errors = ResizeArray<string> ()
-
-            // Check direct fields
-            if this.Whatnot.IsNone then
-                errors.Add ("Argument '--whatnot' is required for Mode2.")
-
-            // Assemble nested state (which includes its own validation)
-            let thingsResult = this.ThingsState.Assemble ()
-            let mutable thingsValue = Unchecked.defaultof<_>
-
-            match thingsResult with
-            | Ok v -> thingsValue <- v
-            | Error nestedErrors -> errors.AddRange (nestedErrors |> List.map (sprintf "Things: %s")) // Add context
-
-            if errors.Count = 0 then
-                {
-                    Things = thingsValue
-                    Whatnot = this.Whatnot.Value
-                }
-                |> Ok
-            else
-                Error (errors |> Seq.toList)
-
-
-    /// State for a single candidate parse path for the Modes DU (Structure unchanged)
-    type private CandidateParseState_Modes =
-        {
-            CaseName : string // "Mode1" or "Mode2"
-            mutable IsViable : bool
-            Errors : ResizeArray<string> // Errors specific to this candidate's path
-            ConsumedArgIndices : System.Collections.Generic.HashSet<int> // Indices consumed *by this candidate*
-            CaseState : obj // Holds either State_Mode1 or State_Mode2
-        }
-
-        static member CreateMode1 () =
-            {
-                CaseName = "Mode1"
-                IsViable = true
-                Errors = ResizeArray ()
-                ConsumedArgIndices = System.Collections.Generic.HashSet ()
-                CaseState = State_Mode1.Create () :> obj
-            }
-
-        static member CreateMode2 () =
-            {
-                CaseName = "Mode2"
-                IsViable = true
-                Errors = ResizeArray ()
-                ConsumedArgIndices = System.Collections.Generic.HashSet ()
-                CaseState = State_Mode2.Create () :> obj
-            }
-
-    //--------------------------------------------------------------------------
-    // Main Parser Logic
-    //--------------------------------------------------------------------------
-
-    type private ParseState_Args =
-        | AwaitingArg
-        | AwaitingValue of keyIndex : int * key : string
-
-    let parse' (getEnvironmentVariable : string -> string) (args : string list) : Args =
-        let ArgParser_errors = ResizeArray () // Global errors accumulator
-
-        let helpText () =
-            // Help text generation unchanged
-            [
-                (sprintf "%s  int32%s%s" (sprintf "--%s" "info1") "" " (for Mode1/Mode2 Things)")
-                (sprintf "%s  string%s%s" (sprintf "--%s" "info2") "" " (for Mode1/Mode2 Things)")
-                (sprintf "%s  string%s%s" (sprintf "--%s" "rest") " (can be repeated)" " (for Mode1 Things)")
-                (sprintf "%s  int32%s%s" (sprintf "--%s" "rest") " (can be repeated)" " (for Mode2 Things)")
-                (sprintf "%s  int32%s%s" (sprintf "--%s" "whatnot") "" " (for Mode1)")
-                (sprintf "%s  DateTime%s%s" (sprintf "--%s" "whatnot") "" " (for Mode2)")
-                (sprintf "%s  string%s%s" (sprintf "--%s" "other-args") " (positional args) (can be repeated)" "")
-            ]
-            |> String.concat "\n"
-
-        let arg_OtherArgs : string ResizeArray = ResizeArray ()
-
-        let mutable candidates_WhatToDo : CandidateParseState_Modes list =
-            [
-                CandidateParseState_Modes.CreateMode1 ()
-                CandidateParseState_Modes.CreateMode2 ()
-            ]
-
-        let consumedArgIndices_WhatToDo = System.Collections.Generic.HashSet<int> ()
-
-        //----------------------------------------------------------------------
-        // Helper functions for applying args (applyKeyValueToSubModeXState unchanged)
-        //----------------------------------------------------------------------
-        let applyKeyValueToSubMode1State
-            (argIndex : int)
-            (keyIndex : int)
-            (key : string)
-            (value : string)
-            (subState : State_SubMode1)
-            (candidate : CandidateParseState_Modes)
-            : unit
-            =
-            // ... (Implementation identical to previous version) ...
-            if String.Equals (key, "--info1", StringComparison.OrdinalIgnoreCase) then
-                match subState.Info1 with
-                | Some _ ->
-                    candidate.Errors.Add (sprintf "Argument '--info1' supplied multiple times (SubMode1)")
-                    candidate.IsViable <- false
-                | None ->
-                    try
-                        subState.Info1 <- Some (Int32.Parse value)
-                        candidate.ConsumedArgIndices.Add argIndex |> ignore
-                        candidate.ConsumedArgIndices.Add keyIndex |> ignore
-                    with ex ->
-                        candidate.Errors.Add (
-                            sprintf "Failed to parse '%s' for --info1 (SubMode1): %s" value ex.Message
-                        )
-
-                        candidate.IsViable <- false
-            elif String.Equals (key, "--info2", StringComparison.OrdinalIgnoreCase) then
-                match subState.Info2 with
-                | Some _ ->
-                    candidate.Errors.Add (sprintf "Argument '--info2' supplied multiple times (SubMode1)")
-                    candidate.IsViable <- false
-                | None ->
-                    subState.Info2 <- Some value
-                    candidate.ConsumedArgIndices.Add argIndex |> ignore
-                    candidate.ConsumedArgIndices.Add keyIndex |> ignore
-            elif String.Equals (key, "--rest", StringComparison.OrdinalIgnoreCase) then
-                subState.Rest.Add value
-                candidate.ConsumedArgIndices.Add argIndex |> ignore
-                candidate.ConsumedArgIndices.Add keyIndex |> ignore
-            else
-                ()
-
-        let applyKeyValueToSubMode2State
-            (argIndex : int)
-            (keyIndex : int)
-            (key : string)
-            (value : string)
-            (subState : State_SubMode2)
-            (candidate : CandidateParseState_Modes)
-            : unit
-            =
-            // ... (Implementation identical to previous version) ...
-            if String.Equals (key, "--info1", StringComparison.OrdinalIgnoreCase) then
-                match subState.Info1 with
-                | Some _ ->
-                    candidate.Errors.Add (sprintf "Argument '--info1' supplied multiple times (SubMode2)")
-                    candidate.IsViable <- false
-                | None ->
-                    try
-                        subState.Info1 <- Some (Int32.Parse value)
-                        candidate.ConsumedArgIndices.Add argIndex |> ignore
-                        candidate.ConsumedArgIndices.Add keyIndex |> ignore
-                    with ex ->
-                        candidate.Errors.Add (
-                            sprintf "Failed to parse '%s' for --info1 (SubMode2): %s" value ex.Message
-                        )
-
-                        candidate.IsViable <- false
-            elif String.Equals (key, "--info2", StringComparison.OrdinalIgnoreCase) then
-                match subState.Info2 with
-                | Some _ ->
-                    candidate.Errors.Add (sprintf "Argument '--info2' supplied multiple times (SubMode2)")
-                    candidate.IsViable <- false
-                | None ->
-                    subState.Info2 <- Some value
-                    candidate.ConsumedArgIndices.Add argIndex |> ignore
-                    candidate.ConsumedArgIndices.Add keyIndex |> ignore
-            elif String.Equals (key, "--rest", StringComparison.OrdinalIgnoreCase) then
-                try
-                    subState.Rest.Add (Int32.Parse value)
-                    candidate.ConsumedArgIndices.Add argIndex |> ignore
-                    candidate.ConsumedArgIndices.Add keyIndex |> ignore
-                with ex ->
-                    candidate.Errors.Add (
-                        sprintf "Failed to parse '%s' as int32 for --rest (SubMode2): %s" value ex.Message
-                    )
-
-                    candidate.IsViable <- false
-            else
-                ()
-
-        //----------------------------------------------------------------------
-        // Routing and Main Application Logic (applyKeyValueToCandidate unchanged)
-        //----------------------------------------------------------------------
-        let applyKeyValueToCandidate
-            (argIndex : int, keyIndex : int, key : string, value : string)
-            (candidate : CandidateParseState_Modes)
-            : unit
-            =
-            // ... (Implementation identical to previous version, calling sub-state helpers) ...
-            if not candidate.IsViable then
-                ()
-            else
-
-            match candidate.CaseName with
-            | "Mode1" ->
-                let state = candidate.CaseState :?> State_Mode1
-
-                if String.Equals (key, "--whatnot", StringComparison.OrdinalIgnoreCase) then
-                    match state.Whatnot with
-                    | Some _ ->
-                        candidate.Errors.Add (
-                            sprintf "Argument '--whatnot' supplied multiple times for Mode1 candidate"
-                        )
-
-                        candidate.IsViable <- false
-                    | None ->
-                        try
-                            state.Whatnot <- Some (Int32.Parse value)
-                            candidate.ConsumedArgIndices.Add argIndex |> ignore
-                            candidate.ConsumedArgIndices.Add keyIndex |> ignore
-                        with ex ->
-                            candidate.Errors.Add (
-                                sprintf "Failed to parse '%s' as int32 for --whatnot (Mode1): %s" value ex.Message
-                            )
-
-                            candidate.IsViable <- false
-                elif key = "--info1" || key = "--info2" || key = "--rest" then
-                    applyKeyValueToSubMode1State argIndex keyIndex key value state.ThingsState candidate
-                else
-                    ()
-            | "Mode2" ->
-                let state = candidate.CaseState :?> State_Mode2
-
-                if String.Equals (key, "--whatnot", StringComparison.OrdinalIgnoreCase) then
-                    match state.Whatnot with
-                    | Some _ ->
-                        candidate.Errors.Add (
-                            sprintf "Argument '--whatnot' supplied multiple times for Mode2 candidate"
-                        )
-
-                        candidate.IsViable <- false
-                    | None ->
-                        try
-                            state.Whatnot <- Some (DateTime.Parse value)
-                            candidate.ConsumedArgIndices.Add argIndex |> ignore
-                            candidate.ConsumedArgIndices.Add keyIndex |> ignore
-                        with ex ->
-                            candidate.Errors.Add (
-                                sprintf "Failed to parse '%s' as DateTime for --whatnot (Mode2): %s" value ex.Message
-                            )
-
-                            candidate.IsViable <- false
-                elif key = "--info1" || key = "--info2" || key = "--rest" then
-                    applyKeyValueToSubMode2State argIndex keyIndex key value state.ThingsState candidate
-                else
-                    ()
-            | _ -> failwith "Internal error: Unknown case name"
-
-        // processKeyValue, setFlagValue, and main loop `go` are identical to previous version
-        let processKeyValue (keyIndex : int, key : string, valueIndex : int, value : string) : bool =
-            let mutable handled = false
-
-            for candidate in candidates_WhatToDo do
-                let initialConsumedCount = candidate.ConsumedArgIndices.Count
-
-                if candidate.IsViable then
-                    applyKeyValueToCandidate (valueIndex, keyIndex, key, value) candidate
-
-                if candidate.IsViable && candidate.ConsumedArgIndices.Count > initialConsumedCount then
-                    handled <- true
-                    consumedArgIndices_WhatToDo.Add keyIndex |> ignore
-                    consumedArgIndices_WhatToDo.Add valueIndex |> ignore
-
-            handled
-
-        let setFlagValue (keyIndex : int) (key : string) : bool = false // No flags
-
-        let rec go (state : ParseState_Args) (args : (int * string) list) =
-            // ... (Implementation identical to previous version) ...
-            match args with
-            | [] ->
-                match state with
-                | ParseState_Args.AwaitingArg -> ()
-                | ParseState_Args.AwaitingValue (i, k) ->
-                    if not (setFlagValue i k) then
-                        ArgParser_errors.Add (sprintf "Trailing argument '%s' (at index %d) requires a value." k i)
-            | (idx, arg) :: rest ->
-                match state with
-                | ParseState_Args.AwaitingArg ->
-                    if arg = "--" then
-                        rest
-                        |> List.iter (fun (i, v) ->
-                            if not (consumedArgIndices_WhatToDo.Contains i) then
-                                arg_OtherArgs.Add v
-                        )
-
-                        go ParseState_Args.AwaitingArg []
-                    elif arg.StartsWith ("--") then
-                        if arg = "--help" then
-                            helpText () |> failwithf "Help text requested:\n%s"
-                        else
-                            let eq = arg.IndexOf ('=')
-
-                            if eq > 0 then
-                                let k = arg.[.. eq - 1]
-                                let v = arg.[eq + 1 ..]
-
-                                if not (processKeyValue (idx, k, idx, v)) then
-                                    if not (consumedArgIndices_WhatToDo.Contains idx) then
-                                        arg_OtherArgs.Add arg
-
-                                go ParseState_Args.AwaitingArg rest
-                            elif setFlagValue idx arg then
-                                consumedArgIndices_WhatToDo.Add idx |> ignore
-                                go ParseState_Args.AwaitingArg rest
-                            else
-                                go (ParseState_Args.AwaitingValue (idx, arg)) rest
-                    else
-                        if not (consumedArgIndices_WhatToDo.Contains idx) then
-                            arg_OtherArgs.Add arg
-
-                        go ParseState_Args.AwaitingArg rest
-                | ParseState_Args.AwaitingValue (keyIdx, key) ->
-                    if processKeyValue (keyIdx, key, idx, arg) then
-                        go ParseState_Args.AwaitingArg rest
-                    elif setFlagValue keyIdx key then
-                        consumedArgIndices_WhatToDo.Add keyIdx |> ignore<bool>
-                        go ParseState_Args.AwaitingArg ((idx, arg) :: rest) // Reprocess arg
-                    elif not (consumedArgIndices_WhatToDo.Contains keyIdx) then
-                        arg_OtherArgs.Add key
-
-                        if not (consumedArgIndices_WhatToDo.Contains idx) then
-                            arg_OtherArgs.Add arg
-
-                        go ParseState_Args.AwaitingArg rest
-
-        args |> List.mapi (fun i s -> (i, s)) |> go ParseState_Args.AwaitingArg
-
-        //----------------------------------------------------------------------
-        // Final Validation and Assembly (Uses new Assemble methods)
-        //----------------------------------------------------------------------
-        let viableWinners = candidates_WhatToDo |> List.filter (fun c -> c.IsViable)
-        // No longer filter based on IsComplete here; Assemble handles it.
-        // Still need to check for relative leftovers if that logic were implemented.
-
-        let whatToDoResult =
-            match viableWinners with
-            | [] ->
-                // Add specific errors from candidates that were viable *before* Assemble check
-                ArgParser_errors.Add ("No valid parse found for 'WhatToDo'.")
-
-                candidates_WhatToDo
-                |> List.iter (fun c ->
-                    if c.Errors.Count <> 0 then
-                        ArgParser_errors.Add (
-                            sprintf "  Candidate %s parse errors: %s" c.CaseName (String.concat "; " c.Errors)
-                        )
-                // Potentially try to Assemble even non-viable ones to get completion errors? Maybe too complex.
-                )
-
-                Unchecked.defaultof<_> // Error path
-
-            | [ winner ] ->
-                // Assemble the winning case, checking the Result for completion errors
-                match winner.CaseName with
-                | "Mode1" ->
-                    match (winner.CaseState :?> State_Mode1).Assemble () with
-                    | Ok mode1Value -> Modes.Mode1 mode1Value
-                    | Error completionErrors ->
-                        ArgParser_errors.Add (sprintf "Validation failed for selected candidate Mode1:")
-                        ArgParser_errors.AddRange completionErrors
-                        Unchecked.defaultof<_> // Error path
-                | "Mode2" ->
-                    match (winner.CaseState :?> State_Mode2).Assemble () with
-                    | Ok mode2Value -> Modes.Mode2 mode2Value
-                    | Error completionErrors ->
-                        ArgParser_errors.Add (sprintf "Validation failed for selected candidate Mode2:")
-                        ArgParser_errors.AddRange completionErrors
-                        Unchecked.defaultof<_> // Error path
-                | _ -> failwith "Internal error: Unknown winning case name"
-
-            | winners -> // Ambiguous parse
-                ArgParser_errors.Add ("Ambiguous parse for 'WhatToDo'. Multiple modes potentially viable:")
-
-                winners
-                |> List.iter (fun c ->
-                    ArgParser_errors.Add (
-                        sprintf
-                            "  - %s (Initial Errors: %s)"
-                            c.CaseName
-                            (if c.Errors.Count = 0 then
-                                 "None"
-                             else
-                                 String.concat "; " c.Errors)
-                    )
-                )
-
-                Unchecked.defaultof<_> // Error path
-
-        // Finalize OtherArgs (unchanged)
-        let otherArgsResult = arg_OtherArgs |> Seq.toList
-
-        // Assemble Final Result or Fail (unchanged)
-        if ArgParser_errors.Count > 0 then
-            ArgParser_errors
-            |> String.concat "\n"
-            |> failwithf "Errors during parse!\n%s\n\nHelp Text:\n%s" (helpText ())
-        else
-            {
-                WhatToDo = whatToDoResult
-                OtherArgs = otherArgsResult
-            }
-
-    let parse (args : string list) : Args =
-        parse' System.Environment.GetEnvironmentVariable args

Playground/Playground.fsproj

@@ -1,19 +0,0 @@
-<Project Sdk="Microsoft.NET.Sdk">
-
-    <PropertyGroup>
-        <TargetFramework>net9.0</TargetFramework>
-        <GenerateDocumentationFile>true</GenerateDocumentationFile>
-      <OutputType>Exe</OutputType>
-    </PropertyGroup>
-
-    <ItemGroup>
-        <Compile Include="Domain.fs" />
-        <Compile Include="Library.fs"/>
-        <Compile Include="Program.fs" />
-    </ItemGroup>
-
-    <ItemGroup>
-      <ProjectReference Include="..\WoofWare.Myriad.Plugins.Attributes\WoofWare.Myriad.Plugins.Attributes.fsproj" />
-    </ItemGroup>
-
-</Project>

Playground/Program.fs

@@ -1,10 +0,0 @@
-namespace Playground
-
-module Program =
-    [<EntryPoint>]
-    let main argv =
-        [ "--whatnot=2024-01-12" ; "--info1=4" ; "--info2=hi" ]
-        |> Args.parse
-        |> printfn "%O"
-
-        0

WoofWare.Myriad.Plugins.Test/TestArgParser/TestArgParser.fs

@@ -79,8 +79,11 @@ module TestArgParser =
 
         exc.Message
         |> shouldEqual
-            """Errors during parse!
-Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `--rest=` syntax, or place them after a trailing `--`. --non-existent"""
+            """Unable to process supplied arg --non-existent. Help text follows.
+--foo  int32 : This is a foo!
+--bar  string
+--baz  bool
+--rest  string (positional args) (can be repeated) : Here's where the rest of the args go"""
 
     [<Test>]
     let ``Can supply positional args with key`` () =
@@ -315,7 +318,8 @@ Required argument '--baz' received no value"""
         exc.Message
         |> shouldEqual
             """Errors during parse!
-Input string was not in a correct format. (at arg --invariant-exact=23:59)"""
+Input string was not in a correct format. (at arg --invariant-exact=23:59)
+Required argument '--invariant-exact' received no value"""
 
         let exc =
             Assert.Throws<exn> (fun () ->
@@ -333,7 +337,8 @@ Input string was not in a correct format. (at arg --invariant-exact=23:59)"""
         exc.Message
         |> shouldEqual
             """Errors during parse!
-Input string was not in a correct format. (at arg --exact=11:34)"""
+Input string was not in a correct format. (at arg --exact=11:34)
+Required argument '--exact' received no value"""
 
         count.Value |> shouldEqual 0
 
@@ -439,7 +444,7 @@ Input string was not in a correct format. (at arg --exact=11:34)"""
         ]
         |> List.map TestCaseData
 
-    [<TestCaseSource(nameof boolCases)>]
+    [<TestCaseSource(nameof (boolCases))>]
     let ``Bool env vars can be populated`` (envValue : string, boolValue : bool) =
         let getEnvVar (s : string) =
             s |> shouldEqual "CONSUMEPLUGIN_THINGS"
@@ -599,10 +604,7 @@ Input string was not in a correct format. (at arg --exact=11:34)"""
             )
 
         exc.Message
-        |> shouldEqual
-            """Errors during parse!
-Required argument '--do-something-else' received no value
-Required argument '--turn-it-on' received no value"""
+        |> shouldEqual """Unable to process argument --do-the-thing=foo as key --do-the-thing and value foo"""
 
     [<Test>]
     let ``Long-form args help text`` () =
@@ -690,9 +692,7 @@ Required argument '--turn-it-on' received no value"""
             )
 
         exc.Message
-        |> shouldEqual
-            """Errors during parse!
-Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `--dont-grab-everything=` syntax, or place them after a trailing `--`. --b=false --c"""
+        |> shouldEqual """Unable to process argument --b=false as key --b and value false"""
 
         let exc =
             Assert.Throws<exn> (fun () ->
@@ -703,6 +703,4 @@ Unmatched args which look like they are meant to be flags. If you intended them
         // Again perhaps eccentric!
         // Again, we don't try to detect that the user has missed out the desired argument to `--a`.
         exc.Message
-        |> shouldEqual
-            """Errors during parse!
-Unmatched args which look like they are meant to be flags. If you intended them as positional args, explicitly pass them with the `--my-arg-name=` syntax, or place them after a trailing `--`. --c=hi"""
+        |> shouldEqual """Unable to process argument --c=hi as key --c and value hi"""

WoofWare.Myriad.Plugins.Test/TestArgParser/TestArgsWithUnions.fs

@@ -1,21 +0,0 @@
-namespace WoofWare.Myriad.Plugins.Test
-
-open FsUnitTyped
-open NUnit.Framework
-open ConsumePlugin.ArgsWithUnions
-
-[<TestFixture>]
-module TestArgsWithUnions =
-
-    let argsWithUnionsCases =
-        [
-            ["--token" ; "hello" ; "--foo" ; "3" ; "--bar=hi" ; "--baz"], { Auth = AuthOptions.Token { Token = "hello" } ; Basics = { Foo = 3 ; Bar = "hi" ; Baz = true ; Rest = [] } }
-        ]
-        |> List.map TestCaseData
-
-    [<TestCaseSource (nameof argsWithUnionsCases)>]
-    let ``foo`` (args : string list, expected : DoTheThing) : unit =
-        args
-        |> DoTheThing.parse' (fun _ -> failwith "didn't expect env var")
-        |> shouldEqual expected
-

WoofWare.Myriad.Plugins.Test/WoofWare.Myriad.Plugins.Test.fsproj

@@ -13,7 +13,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <!--
     <Compile Include="HttpClient.fs"/>
     <Compile Include="PureGymDtos.fs"/>
     <Compile Include="TestJsonParse\TestJsonParse.fs" />
@@ -35,14 +34,10 @@
     <Compile Include="TestCataGenerator\TestGift.fs" />
     <Compile Include="TestCataGenerator\TestMyList.fs" />
     <Compile Include="TestCataGenerator\TestMyList2.fs" />
-    -->
     <Compile Include="TestArgParser\TestArgParser.fs" />
-    <Compile Include="TestArgParser\TestArgsWithUnions.fs" />
-    <!--
     <Compile Include="TestSwagger\TestSwaggerParse.fs" />
     <Compile Include="TestRemoveOptions.fs"/>
     <Compile Include="TestSurface.fs"/>
-    -->
     <None Include="../.github/workflows/dotnet.yaml" />
   </ItemGroup>
 

WoofWare.Myriad.Plugins/ArgParserGenerator.fs

@@ -7,6 +7,82 @@ open Fantomas.FCS.Text.Range
 open TypeEquality
 open WoofWare.Whippet.Fantomas
 
+type internal ArgParserOutputSpec =
+    {
+        ExtensionMethods : bool
+    }
+
+type internal FlagDu =
+    {
+        Name : Ident
+        Case1Name : Ident
+        Case2Name : Ident
+        /// Hopefully this is simply the const bool True or False, but it might e.g. be a literal
+        Case1Arg : SynExpr
+        /// Hopefully this is simply the const bool True or False, but it might e.g. be a literal
+        Case2Arg : SynExpr
+    }
+
+    static member FromBoolean (flagDu : FlagDu) (value : SynExpr) =
+        SynExpr.ifThenElse
+            (SynExpr.equals value flagDu.Case1Arg)
+            (SynExpr.createLongIdent' [ flagDu.Name ; flagDu.Case2Name ])
+            (SynExpr.createLongIdent' [ flagDu.Name ; flagDu.Case1Name ])
+
+/// The default value of an argument which admits default values can be pulled from different sources.
+/// This defines which source a particular default value comes from.
+type private ArgumentDefaultSpec =
+    /// From parsing the environment variable with the given name (e.g. "WOOFWARE_DISABLE_FOO" or whatever).
+    | EnvironmentVariable of name : SynExpr
+    /// From calling the static member `{typeWeParseInto}.Default{name}()`
+    /// For example, if `type MyArgs = { Thing : Choice<int, int> }`, then
+    /// we would use `MyArgs.DefaultThing () : int`.
+    ///
+    | FunctionCall of name : Ident
+
+type private Accumulation<'choice> =
+    | Required
+    | Optional
+    | Choice of 'choice
+    | List of Accumulation<'choice>
+
+type private ParseFunction<'acc> =
+    {
+        FieldName : Ident
+        TargetVariable : Ident
+        /// Any of the forms in this set are acceptable, but make sure they all start with a dash, or we might
+        /// get confused with positional args or something! I haven't thought that hard about this.
+        /// In the default case, this is `Const("arg-name")` for the `ArgName : blah` field; note that we have
+        /// omitted the initial `--` that will be required at runtime.
+        ArgForm : SynExpr list
+        /// If this is a boolean-like field (e.g. a bool or a flag DU), the help text should look a bit different:
+        /// we should lie to the user about the value of the cases there.
+        /// Similarly, if we're reading from an environment variable with the laxer parsing rules of accepting e.g.
+        /// "0" instead of "false", we need to know if we're reading a bool.
+        /// In that case, `boolCases` is Some, and contains the construction of the flag (or boolean, in which case
+        /// you get no data).
+        BoolCases : Choice<FlagDu, unit> option
+        Help : SynExpr option
+        /// A function string -> %TargetType%, where TargetVariable is probably a `%TargetType% option`.
+        /// (Depending on `Accumulation`, we'll remove the `option` at the end of the parse, asserting that the
+        /// argument was supplied.)
+        /// This is allowed to throw if it fails to parse.
+        Parser : SynExpr
+        /// If `Accumulation` is `List`, then this is the type of the list *element*; analogously for optionals
+        /// and choices and so on.
+        TargetType : SynType
+        Accumulation : 'acc
+    }
+
+    /// A SynExpr of type `string` which we can display to the user at generated-program runtime to display all
+    /// the ways they can refer to this arg.
+    member arg.HumanReadableArgForm : SynExpr =
+        let formatString = List.replicate arg.ArgForm.Length "--%s" |> String.concat " / "
+
+        (SynExpr.applyFunction (SynExpr.createIdent "sprintf") (SynExpr.CreateConst formatString), arg.ArgForm)
+        ||> List.fold SynExpr.applyFunction
+        |> SynExpr.paren
+
 [<RequireQualifiedAccess>]
 type private ChoicePositional =
     | Normal of includeFlagLike : SynExpr option
@@ -38,14 +114,14 @@ type private ParseTree<'hasPositional> =
     /// `assemble` takes the SynExpr's (e.g. each record field contents) corresponding to each `Ident` in
     /// the branch (e.g. each record field name),
     /// and composes them into a `SynExpr` (e.g. the record-typed object).
-    | DescendRecord of
+    | Branch of
         fields : (Ident * ParseTree<HasNoPositional>) list *
         assemble : (Map<string, SynExpr> -> SynExpr) *
         Teq<'hasPositional, HasNoPositional>
     /// `assemble` takes the SynExpr's (e.g. each record field contents) corresponding to each `Ident` in
     /// the branch (e.g. each record field name),
     /// and composes them into a `SynExpr` (e.g. the record-typed object).
-    | DescendRecordPos of
+    | BranchPos of
         posField : Ident *
         fields : ParseTree<HasPositional> *
         (Ident * ParseTree<HasNoPositional>) list *
@@ -108,6 +184,63 @@ module private ParseTree =
 
         go None ([], None) subs
 
+    let rec accumulatorsNonPos (tree : ParseTree<HasNoPositional>) : ParseFunctionNonPositional list =
+        match tree with
+        | ParseTree.PositionalLeaf (_, teq) -> exFalso teq
+        | ParseTree.BranchPos (_, _, _, _, teq) -> exFalso teq
+        | ParseTree.NonPositionalLeaf (pf, _) -> [ pf ]
+        | ParseTree.Branch (trees, _, _) -> trees |> List.collect (snd >> accumulatorsNonPos)
+
+    /// Returns the positional arg separately.
+    let rec accumulatorsPos
+        (tree : ParseTree<HasPositional>)
+        : ParseFunctionNonPositional list * ParseFunctionPositional
+        =
+        match tree with
+        | ParseTree.PositionalLeaf (pf, _) -> [], pf
+        | ParseTree.NonPositionalLeaf (_, teq) -> exFalso' teq
+        | ParseTree.Branch (_, _, teq) -> exFalso' teq
+        | ParseTree.BranchPos (_, tree, trees, _, _) ->
+            let nonPos = trees |> List.collect (snd >> accumulatorsNonPos)
+
+            let nonPos2, pos = accumulatorsPos tree
+            nonPos @ nonPos2, pos
+
+    /// Collect all the ParseFunctions which are necessary to define variables, throwing away
+    /// all information relevant to composing the resulting variables into records.
+    /// Returns the list of non-positional parsers, and any positional parser that exists.
+    let accumulators<'a> (tree : ParseTree<'a>) : ParseFunctionNonPositional list * ParseFunctionPositional option =
+        // Sad duplication of some code here, but it was the easiest way to make it type-safe :(
+        match tree with
+        | ParseTree.PositionalLeaf (pf, _) -> [], Some pf
+        | ParseTree.NonPositionalLeaf (pf, _) -> [ pf ], None
+        | ParseTree.Branch (trees, _, _) -> trees |> List.collect (snd >> accumulatorsNonPos) |> (fun i -> i, None)
+        | ParseTree.BranchPos (_, tree, trees, _, _) ->
+            let nonPos = trees |> List.collect (snd >> accumulatorsNonPos)
+
+            let nonPos2, pos = accumulatorsPos tree
+            nonPos @ nonPos2, Some pos
+
+        |> fun (nonPos, pos) ->
+            let duplicateArgs =
+                // This is best-effort. We can't necessarily detect all SynExprs here, but usually it'll be strings.
+                Option.toList (pos |> Option.map _.ArgForm) @ (nonPos |> List.map _.ArgForm)
+                |> Seq.concat
+                |> Seq.choose (fun expr ->
+                    match expr |> SynExpr.stripOptionalParen with
+                    | SynExpr.Const (SynConst.String (s, _, _), _) -> Some s
+                    | _ -> None
+                )
+                |> List.ofSeq
+                |> List.groupBy id
+                |> List.choose (fun (key, v) -> if v.Length > 1 then Some key else None)
+
+            match duplicateArgs with
+            | [] -> nonPos, pos
+            | dups ->
+                let dups = dups |> String.concat " "
+                failwith $"Duplicate args detected! %s{dups}"
+
     /// Build the return value.
     let rec instantiate<'a> (tree : ParseTree<'a>) : SynExpr =
         match tree with

WoofWare.Myriad.Plugins/JsonParseGenerator.fs

@@ -26,7 +26,7 @@ module internal JsonParseGenerator =
             }
 
     /// (match {indexed} with | null -> raise (System.Collections.Generic.KeyNotFoundException ({propertyName} not found)) | v -> v)
-    let assertNotNull (propertyName : SynExpr) (indexed : SynExpr) =
+    let assertPropertyExists (propertyName : SynExpr) (indexed : SynExpr) =
         let raiseExpr =
             SynExpr.applyFunction
                 (SynExpr.createIdent "sprintf")
@@ -46,28 +46,42 @@ module internal JsonParseGenerator =
         |> SynExpr.createMatch indexed
         |> SynExpr.paren
 
+    let assertNotNull (body : SynExpr) (boundIdent : Ident) : SynExpr =
+        let raiseExpr =
+            SynExpr.CreateConst ()
+            |> SynExpr.applyFunction (SynExpr.createLongIdent [ "System" ; "ArgumentNullException" ])
+            |> SynExpr.paren
+            |> SynExpr.applyFunction (SynExpr.createIdent "raise")
+
+        [
+            SynMatchClause.create SynPat.createNull raiseExpr
+            SynMatchClause.create (SynPat.namedI boundIdent) body
+        ]
+        |> SynExpr.createMatch (SynExpr.createIdent' boundIdent)
+        |> SynExpr.paren
+
     /// {node}.AsValue().GetValue<{typeName}> ()
-    /// If `propertyName` is Some, uses `assertNotNull {node}` instead of `{node}`.
+    /// If `propertyName` is Some, uses `assertPropertyExists {node}` instead of `{node}`.
     let asValueGetValue (propertyName : SynExpr option) (typeName : string) (node : SynExpr) : SynExpr =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsValue"
         |> SynExpr.callGenericMethod' "GetValue" typeName
 
     let asValueGetValueIdent (propertyName : SynExpr option) (typeName : LongIdent) (node : SynExpr) : SynExpr =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsValue"
         |> SynExpr.callGenericMethod (SynLongIdent.createS "GetValue") [ SynType.createLongIdent typeName ]
 
     /// {node}.AsObject()
-    /// If `propertyName` is Some, uses `assertNotNull {node}` instead of `{node}`.
+    /// If `propertyName` is Some, uses `assertPropertyExists {node}` instead of `{node}`.
     let asObject (propertyName : SynExpr option) (node : SynExpr) : SynExpr =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsObject"
 
     /// {type}.jsonParse {node}
@@ -77,8 +91,8 @@ module internal JsonParseGenerator =
 
     /// collectionType is e.g. "List"; we'll be calling `ofSeq` on it.
     /// body is the body of a lambda which takes a parameter `elt`.
-    /// {assertNotNull node}.AsArray()
-    /// |> Seq.map (fun elt -> {body})
+    /// {assertPropertyExists node}.AsArray()
+    /// |> Seq.map (fun elt -> {assertNotNull} {body})
     /// |> {collectionType}.ofSeq
     let asArrayMapped
         (propertyName : SynExpr option)
@@ -89,10 +103,12 @@ module internal JsonParseGenerator =
         =
         match propertyName with
         | None -> node
-        | Some propertyName -> assertNotNull propertyName node
+        | Some propertyName -> assertPropertyExists propertyName node
         |> SynExpr.callMethod "AsArray"
         |> SynExpr.pipeThroughFunction (
-            SynExpr.applyFunction (SynExpr.createLongIdent [ "Seq" ; "map" ]) (SynExpr.createLambda "elt" body)
+            SynExpr.applyFunction
+                (SynExpr.createLongIdent [ "Seq" ; "map" ])
+                (SynExpr.createLambda "elt" (assertNotNull body (Ident.create "elt")))
         )
         |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ collectionType ; "ofSeq" ])
 
@@ -177,27 +193,29 @@ module internal JsonParseGenerator =
         =
         // TODO: parsing format for DateTime etc
         match fieldType with
+        // Struct types
         | DateOnly ->
             node
             |> asValueGetValue propertyName "string"
             |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "DateOnly" ; "Parse" ])
-        | Uri ->
-            node
-            |> asValueGetValue propertyName "string"
-            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Uri" ])
-        | Guid ->
-            node
-            |> asValueGetValue propertyName "string"
-            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Guid" ; "Parse" ])
         | DateTime ->
             node
             |> asValueGetValue propertyName "string"
             |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "DateTime" ; "Parse" ])
+        | NumberType typeName -> parseNumberType options propertyName node typeName
+        | Guid ->
+            node
+            |> asValueGetValue propertyName "string"
+            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Guid" ; "Parse" ])
+        // Reference types
+        | Uri ->
+            node
+            |> asValueGetValue propertyName "string"
+            |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "Uri" ])
         | DateTimeOffset ->
             node
             |> asValueGetValue propertyName "string"
             |> SynExpr.pipeThroughFunction (SynExpr.createLongIdent [ "System" ; "DateTimeOffset" ; "Parse" ])
-        | NumberType typeName -> parseNumberType options propertyName node typeName
         | PrimitiveType typeName -> asValueGetValueIdent propertyName typeName node
         | OptionType ty ->
             let someClause =
@@ -291,7 +309,7 @@ module internal JsonParseGenerator =
 
             match propertyName with
             | None -> node
-            | Some propertyName -> assertNotNull propertyName node
+            | Some propertyName -> assertPropertyExists propertyName node
             |> typeJsonParse typeName
 
     /// propertyName is probably a string literal, but it could be a [<Literal>] variable
@@ -505,7 +523,7 @@ module internal JsonParseGenerator =
                     |> SynExpr.createLet
                         [
                             SynExpr.index (SynExpr.CreateConst "data") (SynExpr.createIdent "node")
-                            |> assertNotNull (SynExpr.CreateConst "data")
+                            |> assertPropertyExists (SynExpr.CreateConst "data")
                             |> SynBinding.basic [ Ident.create "node" ] []
                         ]
 
@@ -553,7 +571,7 @@ module internal JsonParseGenerator =
 
                 SynExpr.createIdent "node"
                 |> SynExpr.index property
-                |> assertNotNull property
+                |> assertPropertyExists property
                 |> SynExpr.pipeThroughFunction (
                     SynExpr.createLambda "v" (SynExpr.callGenericMethod' "GetValue" "string" (SynExpr.createIdent "v"))
                 )

WoofWare.Myriad.Plugins/List.fs

@@ -21,13 +21,3 @@ module private List =
             | Some head :: tail -> go (head :: acc) tail
 
         go [] l
-
-    /// Return the first error encountered, or the entire list.
-    let allOkOrError<'ok, 'err> (l : Result<'ok, 'err> list) : Result<'ok list, 'err> =
-        let rec go acc l =
-            match l with
-            | [] -> Ok (List.rev acc)
-            | Error e :: _ -> Error e
-            | Ok o :: rest -> go (o :: acc) rest
-
-        go [] l

WoofWare.Myriad.Plugins/WoofWare.Myriad.Plugins.fsproj

@@ -40,8 +40,7 @@
     <Compile Include="JsonParseGenerator.fs"/>
     <Compile Include="HttpClientGenerator.fs"/>
     <Compile Include="CataGenerator.fs" />
-    <Compile Include="ShibaGenerator.fs" />
-    <None Include="ArgParserGenerator.fs" />
+    <Compile Include="ArgParserGenerator.fs" />
     <Compile Include="Swagger.fs" />
     <Compile Include="SwaggerClientGenerator.fs" />
     <None Include="ApacheLicence.txt" />

WoofWare.Myriad.Plugins/version.json

@@ -1,5 +1,5 @@
 {
-  "version": "4.0",
+  "version": "5.0",
   "publicReleaseRefSpec": [
     "^refs/heads/main$"
   ],
@@ -11,4 +11,4 @@
     ":/README.md",
     ":/Directory.Build.props"
   ]
-}
+}

WoofWare.Myriad.sln

@@ -10,8 +10,6 @@ Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "WoofWare.Myriad.Plugins.Att
 EndProject
 Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "WoofWare.Myriad.Plugins.Attributes.Test", "WoofWare.Myriad.Plugins.Attributes\Test\WoofWare.Myriad.Plugins.Attributes.Test.fsproj", "{26DC0C94-85F2-45B4-8FA1-1B27201F7AFB}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Playground", "Playground\Playground.fsproj", "{6DF8C756-DE59-4AFF-A4BB-2D05C74192A4}"
-EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -38,9 +36,5 @@ Global
 		{26DC0C94-85F2-45B4-8FA1-1B27201F7AFB}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{26DC0C94-85F2-45B4-8FA1-1B27201F7AFB}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{26DC0C94-85F2-45B4-8FA1-1B27201F7AFB}.Release|Any CPU.Build.0 = Release|Any CPU
-		{6DF8C756-DE59-4AFF-A4BB-2D05C74192A4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{6DF8C756-DE59-4AFF-A4BB-2D05C74192A4}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{6DF8C756-DE59-4AFF-A4BB-2D05C74192A4}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{6DF8C756-DE59-4AFF-A4BB-2D05C74192A4}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

flake.lock

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1744502386,
-        "narHash": "sha256-QAd1L37eU7ktL2WeLLLTmI6P9moz9+a/ONO8qNBYJgM=",
+        "lastModified": 1744868846,
+        "narHash": "sha256-5RJTdUHDmj12Qsv7XOhuospjAjATNiTMElplWnJE9Hs=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "f6db44a8daa59c40ae41ba6e5823ec77fe0d2124",
+        "rev": "ebe4301cbd8f81c4f8d3244b3632338bbeb6d49c",
         "type": "github"
       },
       "original": {