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WoofWare.Myriad/WoofWare.Myriad.Plugins/JsonSerializeGenerator.fs
2024-02-07 01:27:57 +00:00

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namespace WoofWare.Myriad.Plugins
open System
open System.Text
open Fantomas.FCS.Syntax
open Fantomas.FCS.SyntaxTrivia
open Fantomas.FCS.Xml
open Myriad.Core
type internal JsonSerializeOutputSpec =
{
ExtensionMethods : bool
}
[<RequireQualifiedAccess>]
module internal JsonSerializeGenerator =
open Fantomas.FCS.Text.Range
open Myriad.Core.Ast
/// Given `input.Ident`, for example, choose how to add it to the ambient `node`.
/// The result is a line like `(fun ident -> InnerType.toJsonNode ident)` or `(fun ident -> JsonValue.Create ident)`.
let rec serializeNode (fieldType : SynType) : SynExpr =
// TODO: serialization format for DateTime etc
match fieldType with
| DateOnly
| DateTime
| NumberType _
| PrimitiveType _
| Guid
| Uri ->
// JsonValue.Create<type>
SynExpr.TypeApp (
SynExpr.CreateLongIdent (
SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonValue" ; "Create" ]
),
range0,
[ fieldType ],
[],
Some range0,
range0,
range0
)
| OptionType ty ->
// fun field -> match field with | None -> JsonValue.Create null | Some v -> {serializeNode ty} field
SynExpr.CreateMatch (
SynExpr.CreateIdentString "field",
[
SynMatchClause.Create (
SynPat.CreateLongIdent (SynLongIdent.CreateString "None", []),
None,
// The absolutely galaxy-brained implementation of JsonValue has `JsonValue.Parse "null"`
// identically equal to null. We have to work around this later, but we might as well just
// be efficient here and whip up the null directly.
SynExpr.CreateNull
|> SynExpr.upcast' (
SynType.CreateLongIdent (
SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ]
)
)
)
SynMatchClause.Create (
SynPat.CreateLongIdent (
SynLongIdent.CreateString "Some",
[ SynPat.CreateNamed (Ident.Create "field") ]
),
None,
SynExpr.CreateApp (serializeNode ty, SynExpr.CreateIdentString "field")
|> SynExpr.CreateParen
|> SynExpr.upcast' (
SynType.CreateLongIdent (
SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ]
)
)
)
]
)
|> SynExpr.createLambda "field"
| ArrayType ty
| ListType ty ->
// fun field ->
// let arr = JsonArray ()
// for mem in field do arr.Add ({serializeNode} mem)
// arr
SynExpr.LetOrUse (
false,
false,
[
SynBinding.Let (
pattern = SynPat.CreateNamed (Ident.Create "arr"),
expr =
SynExpr.CreateApp (
SynExpr.CreateLongIdent (
SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonArray" ]
),
SynExpr.CreateConst SynConst.Unit
)
)
],
SynExpr.CreateSequential
[
SynExpr.ForEach (
DebugPointAtFor.Yes range0,
DebugPointAtInOrTo.Yes range0,
SeqExprOnly.SeqExprOnly false,
true,
SynPat.CreateNamed (Ident.Create "mem"),
SynExpr.CreateIdent (Ident.Create "field"),
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.Create [ "arr" ; "Add" ]),
SynExpr.CreateParen (
SynExpr.CreateApp (serializeNode ty, SynExpr.CreateIdentString "mem")
)
),
range0
)
SynExpr.CreateIdentString "arr"
],
range0,
{
InKeyword = None
}
)
|> SynExpr.createLambda "field"
| IDictionaryType (keyType, valueType)
| DictionaryType (keyType, valueType)
| IReadOnlyDictionaryType (keyType, valueType)
| MapType (keyType, valueType) ->
// fun field ->
// let ret = JsonObject ()
// for (KeyValue(key, value)) in field do
// ret.Add (key.ToString (), {serializeNode} value)
// ret
SynExpr.LetOrUse (
false,
false,
[
SynBinding.Let (
pattern = SynPat.CreateNamed (Ident.Create "ret"),
expr =
SynExpr.CreateApp (
SynExpr.CreateLongIdent (
SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonObject" ]
),
SynExpr.CreateConst SynConst.Unit
)
)
],
SynExpr.CreateSequential
[
SynExpr.ForEach (
DebugPointAtFor.Yes range0,
DebugPointAtInOrTo.Yes range0,
SeqExprOnly.SeqExprOnly false,
true,
SynPat.CreateParen (
SynPat.CreateLongIdent (
SynLongIdent.CreateString "KeyValue",
[
SynPat.CreateParen (
SynPat.Tuple (
false,
[
SynPat.CreateNamed (Ident.Create "key")
SynPat.CreateNamed (Ident.Create "value")
],
[ range0 ],
range0
)
)
]
)
),
SynExpr.CreateIdent (Ident.Create "field"),
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.Create [ "ret" ; "Add" ]),
SynExpr.CreateParenedTuple
[
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.Create [ "key" ; "ToString" ]),
SynExpr.CreateConst SynConst.Unit
)
SynExpr.CreateApp (serializeNode valueType, SynExpr.CreateIdentString "value")
]
),
range0
)
SynExpr.CreateIdentString "ret"
],
range0,
{
InKeyword = None
}
)
|> SynExpr.createLambda "field"
| _ ->
// {type}.toJsonNode
let typeName =
match fieldType with
| SynType.LongIdent ident -> ident.LongIdent
| _ -> failwith $"Unrecognised type: %+A{fieldType}"
SynExpr.CreateLongIdent (SynLongIdent.CreateFromLongIdent (typeName @ [ Ident.Create "toJsonNode" ]))
/// propertyName is probably a string literal, but it could be a [<Literal>] variable
/// `node.Add ({propertyName}, {toJsonNode})`
let createSerializeRhs (propertyName : SynExpr) (fieldId : Ident) (fieldType : SynType) : SynExpr =
let func = SynExpr.CreateLongIdent (SynLongIdent.Create [ "node" ; "Add" ])
let args =
SynExpr.CreateParenedTuple
[
propertyName
SynExpr.CreateApp (
serializeNode fieldType,
SynExpr.CreateLongIdent (SynLongIdent.CreateFromLongIdent [ Ident.Create "input" ; fieldId ])
)
]
SynExpr.CreateApp (func, args)
let createMaker (spec : JsonSerializeOutputSpec) (typeName : LongIdent) (fields : SynField list) =
let xmlDoc = PreXmlDoc.Create " Serialize to a JSON node"
let returnInfo =
SynBindingReturnInfo.Create (
SynType.LongIdent (SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonNode" ])
)
let inputArg = Ident.Create "input"
let functionName = Ident.Create "toJsonNode"
let inputVal =
let memberFlags =
if spec.ExtensionMethods then
{
SynMemberFlags.IsInstance = false
SynMemberFlags.IsDispatchSlot = false
SynMemberFlags.IsOverrideOrExplicitImpl = false
SynMemberFlags.IsFinal = false
SynMemberFlags.GetterOrSetterIsCompilerGenerated = false
SynMemberFlags.MemberKind = SynMemberKind.Member
}
|> Some
else
None
let thisIdOpt = if spec.ExtensionMethods then None else Some inputArg
SynValData.SynValData (
memberFlags,
SynValInfo.SynValInfo ([ [ SynArgInfo.CreateId functionName ] ], SynArgInfo.Empty),
thisIdOpt
)
let assignments =
fields
|> List.map (fun (SynField (attrs, _, id, fieldType, _, _, _, _, _)) ->
let id =
match id with
| None -> failwith "didn't get an ID on field"
| Some id -> id
let attrs = attrs |> List.collect (fun l -> l.Attributes)
let propertyNameAttr =
attrs
|> List.tryFind (fun attr ->
attr.TypeName.AsString.EndsWith ("JsonPropertyName", StringComparison.Ordinal)
)
let propertyName =
match propertyNameAttr with
| None ->
let sb = StringBuilder id.idText.Length
sb.Append (Char.ToLowerInvariant id.idText.[0]) |> ignore
if id.idText.Length > 1 then
sb.Append id.idText.[1..] |> ignore
sb.ToString () |> SynConst.CreateString |> SynExpr.CreateConst
| Some name -> name.ArgExpr
let pattern =
SynPat.LongIdent (
SynLongIdent.CreateFromLongIdent [ id ],
None,
None,
SynArgPats.Empty,
None,
range0
)
createSerializeRhs propertyName id fieldType
)
let finalConstruction =
fields
|> List.map (fun (SynField (_, _, id, _, _, _, _, _, _)) ->
let id =
match id with
| None -> failwith "Expected record field to have an identifying name"
| Some id -> id
(SynLongIdent.CreateFromLongIdent [ id ], true),
Some (SynExpr.CreateLongIdent (SynLongIdent.CreateFromLongIdent [ id ]))
)
|> AstHelper.instantiateRecord
let assignments = assignments |> SynExpr.CreateSequential
let assignments =
SynExpr.LetOrUse (
false,
false,
[
SynBinding.Let (
pattern = SynPat.CreateNamed (Ident.Create "node"),
expr =
SynExpr.CreateApp (
SynExpr.CreateLongIdent (
SynLongIdent.Create [ "System" ; "Text" ; "Json" ; "Nodes" ; "JsonObject" ]
),
SynExpr.CreateConst SynConst.Unit
)
)
],
SynExpr.CreateSequential
[
SynExpr.Do (assignments, range0)
SynExpr.Upcast (SynExpr.CreateIdentString "node", SynType.Anon range0, range0)
],
range0,
{
InKeyword = None
}
)
let pattern =
SynPat.LongIdent (
SynLongIdent.CreateFromLongIdent [ functionName ],
None,
None,
SynArgPats.Pats
[
SynPat.CreateTyped (
SynPat.CreateNamed inputArg,
SynType.LongIdent (SynLongIdent.CreateFromLongIdent typeName)
)
|> SynPat.CreateParen
],
None,
range0
)
if spec.ExtensionMethods then
let binding =
SynBinding.SynBinding (
None,
SynBindingKind.Normal,
false,
false,
[],
xmlDoc,
inputVal,
pattern,
Some returnInfo,
assignments,
range0,
DebugPointAtBinding.NoneAtInvisible,
{
LeadingKeyword = SynLeadingKeyword.StaticMember (range0, range0)
InlineKeyword = None
EqualsRange = Some range0
}
)
let mem = SynMemberDefn.Member (binding, range0)
let containingType =
SynTypeDefn.SynTypeDefn (
SynComponentInfo.Create (typeName, xmldoc = PreXmlDoc.Create " Extension methods for JSON parsing"),
SynTypeDefnRepr.ObjectModel (SynTypeDefnKind.Augmentation range0, [], range0),
[ mem ],
None,
range0,
{
LeadingKeyword = SynTypeDefnLeadingKeyword.Type range0
EqualsRange = None
WithKeyword = None
}
)
SynModuleDecl.Types ([ containingType ], range0)
else
let binding =
SynBinding.Let (
isInline = false,
isMutable = false,
xmldoc = xmlDoc,
returnInfo = returnInfo,
expr = assignments,
valData = inputVal,
pattern = pattern
)
SynModuleDecl.CreateLet [ binding ]
let createRecordModule
(namespaceId : LongIdent)
(opens : SynOpenDeclTarget list)
(spec : JsonSerializeOutputSpec)
(typeDefn : SynTypeDefn)
=
let (SynTypeDefn (synComponentInfo, synTypeDefnRepr, _members, _implicitCtor, _, _)) =
typeDefn
let (SynComponentInfo (_attributes, _typeParams, _constraints, recordId, _, _preferPostfix, _access, _)) =
synComponentInfo
match synTypeDefnRepr with
| SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Record (_accessibility, recordFields, _recordRange), _) ->
let decls = [ createMaker spec recordId recordFields ]
let attributes =
if spec.ExtensionMethods then
[ SynAttributeList.Create SynAttribute.autoOpen ]
else
[
SynAttributeList.Create (SynAttribute.RequireQualifiedAccess ())
SynAttributeList.Create SynAttribute.compilationRepresentation
]
let xmlDoc =
let fullyQualified = recordId |> Seq.map (fun i -> i.idText) |> String.concat "."
let description =
if spec.ExtensionMethods then
"extension members"
else
"methods"
$" Module containing JSON serializing %s{description} for the %s{fullyQualified} type"
|> PreXmlDoc.Create
let moduleName =
if spec.ExtensionMethods then
match recordId with
| [] -> failwith "unexpectedly got an empty identifier for record name"
| recordId ->
let expanded =
List.last recordId
|> fun i -> i.idText
|> fun s -> s + "JsonSerializeExtension"
|> Ident.Create
List.take (List.length recordId - 1) recordId @ [ expanded ]
else
recordId
let info =
SynComponentInfo.Create (moduleName, attributes = attributes, xmldoc = xmlDoc)
let mdl = SynModuleDecl.CreateNestedModule (info, decls)
SynModuleOrNamespace.CreateNamespace (
namespaceId,
decls = (opens |> List.map SynModuleDecl.CreateOpen) @ [ mdl ]
)
| _ -> failwithf "Not a record type"
/// Myriad generator that provides a method (possibly an extension method) for a record type,
/// containing a JSON serialization function.
[<MyriadGenerator("json-serialize")>]
type JsonSerializeGenerator () =
interface IMyriadGenerator with
member _.ValidInputExtensions = [ ".fs" ]
member _.Generate (context : GeneratorContext) =
let ast, _ =
Ast.fromFilename context.InputFilename |> Async.RunSynchronously |> Array.head
let records = Ast.extractRecords ast
let namespaceAndRecords =
records
|> List.choose (fun (ns, types) ->
types
|> List.choose (fun typeDef ->
match Ast.getAttribute<JsonSerializeAttribute> typeDef with
| None -> None
| Some attr ->
let arg =
match SynExpr.stripOptionalParen attr.ArgExpr with
| SynExpr.Const (SynConst.Bool value, _) -> value
| SynExpr.Const (SynConst.Unit, _) -> JsonSerializeAttribute.DefaultIsExtensionMethod
| arg ->
failwith
$"Unrecognised argument %+A{arg} to [<%s{nameof JsonSerializeAttribute}>]. Literals are not supported. Use `true` or `false` (or unit) only."
let spec =
{
ExtensionMethods = arg
}
Some (typeDef, spec)
)
|> function
| [] -> None
| ty -> Some (ns, ty)
)
let opens = AstHelper.extractOpens ast
let modules =
namespaceAndRecords
|> List.collect (fun (ns, records) ->
records
|> List.map (fun (record, spec) ->
let recordModule = JsonSerializeGenerator.createRecordModule ns opens spec record
recordModule
)
)
Output.Ast modules