Files
WoofWare.Myriad/WoofWare.Myriad.Plugins/CataGenerator.fs
2024-02-16 14:26:41 +00:00

865 lines
34 KiB
Forth

namespace WoofWare.Myriad.Plugins
open System.Transactions
open Fantomas.FCS.Syntax
open Fantomas.FCS.SyntaxTrivia
open Fantomas.FCS.Xml
open Myriad.Core
[<RequireQualifiedAccess>]
module internal CataGenerator =
open Fantomas.FCS.Text.Range
open Myriad.Core.Ast
/// Returns a function:
/// let run{Case} (cata : Cata<{typars}>) (x : {Case}) : {TyPar} =
/// let instructions = ResizeArray ()
/// instructions.Add (Instruction.Process{Case} e)
/// let {typar1}Results, {typar2}Results, ... = loop cata instructions
/// { for all non-relevant typars: }
/// if {typar}Results.Count > 0 then failwith "logic error"
/// Seq.exactlyOne {relevantTypar}Stack
let createRunFunction (allTypars : SynType list) (relevantTypar : SynType) (unionType : SynTypeDefn) : SynBinding =
let relevantTypeName =
match unionType with
| SynTypeDefn.SynTypeDefn (SynComponentInfo.SynComponentInfo (longId = id), _, _, _, _, _) -> List.last id
let allTyparNames =
allTypars
|> List.map (fun ty ->
match ty with
| SynType.Var (SynTypar.SynTypar (ident = ident), _) -> ident
| _ -> failwith "logic error in generator"
)
let relevantTyparName =
match relevantTypar with
| SynType.Var (SynTypar.SynTypar (ident = ident), _) -> ident
| _ -> failwith "logic error in generator"
SynBinding.SynBinding (
None,
SynBindingKind.Normal,
false,
false,
[],
PreXmlDoc.Create " Execute the catamorphism.",
SynValData.SynValData (
None,
SynValInfo.SynValInfo (
[ [ SynArgInfo.CreateIdString "cata" ] ; [ SynArgInfo.CreateIdString "x" ] ],
SynArgInfo.SynArgInfo ([], false, None)
),
None
),
SynPat.CreateLongIdent (
SynLongIdent.CreateString ("run" + relevantTypeName.idText),
[
SynPat.CreateParen (
SynPat.CreateTyped (
SynPat.CreateNamed (Ident.Create "cata"),
SynType.App (
SynType.CreateLongIdent "Cata",
Some range0,
allTypars,
List.replicate (allTypars.Length - 1) range0,
Some range0,
false,
range0
)
)
)
SynPat.CreateParen (
SynPat.CreateTyped (
SynPat.CreateNamed (Ident.Create "x"),
SynType.CreateLongIdent (SynLongIdent.CreateFromLongIdent [ relevantTypeName ])
)
)
]
),
Some (SynBindingReturnInfo.Create relevantTypar),
SynExpr.CreateTyped (
SynExpr.LetOrUse (
false,
false,
[
SynBinding.Let (
valData = SynValData.SynValData (None, SynValInfo.Empty, None),
pattern = SynPat.CreateNamed (Ident.Create "instructions"),
expr =
SynExpr.CreateApp (
SynExpr.CreateIdentString "ResizeArray",
SynExpr.CreateConst SynConst.Unit
)
)
],
SynExpr.CreateSequential
[
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.Create [ "instructions" ; "Add" ]),
SynExpr.CreateParen (
SynExpr.CreateApp (
SynExpr.CreateLongIdent (
SynLongIdent.Create [ "Instruction" ; "Process" + relevantTypeName.idText ]
),
SynExpr.CreateLongIdent (SynLongIdent.CreateString "x")
)
)
)
SynExpr.LetOrUse (
false,
false,
[
SynBinding.Let (
valData = SynValData.SynValData (None, SynValInfo.Empty, None),
pattern =
SynPat.Tuple (
false,
List.map
(fun (t : Ident) ->
SynPat.CreateNamed (Ident.Create (t.idText + "Stack"))
)
allTyparNames,
List.replicate (allTypars.Length - 1) range0,
range0
),
expr =
SynExpr.CreateApp (
SynExpr.CreateApp (
SynExpr.CreateIdentString "loop",
SynExpr.CreateIdentString "cata"
),
SynExpr.CreateIdentString "instructions"
)
)
],
// TODO: add the "all other stacks are empty" sanity checks
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.Create [ "Seq" ; "exactlyOne" ]),
SynExpr.CreateIdent (Ident.Create (relevantTyparName.idText + "Stack"))
),
range0,
{
SynExprLetOrUseTrivia.InKeyword = None
}
)
],
range0,
{
InKeyword = None
}
),
relevantTypar
),
range0,
DebugPointAtBinding.NoneAtLet,
{
LeadingKeyword = SynLeadingKeyword.Let range0
InlineKeyword = None
EqualsRange = Some range0
}
)
let getName (ty : SynTypeDefn) : LongIdent =
match ty with
| SynTypeDefn.SynTypeDefn (SynComponentInfo.SynComponentInfo (_, _, _, id, _, _, _, _), _, _, _, _, _) -> id
let getNameKey (ty : SynTypeDefn) : string =
getName ty |> List.map _.idText |> String.concat "/"
let getNameKeyUnion (unionType : SynType) : string =
match unionType with
| SynType.LongIdent (SynLongIdent.SynLongIdent (name, _, _)) -> name |> List.map _.idText |> String.concat "/"
| _ -> failwithf "unrecognised type: %+A" unionType
type UnionField =
{
Type : SynType
Name : Ident option
}
type UnionCase =
{
Name : SynIdent
Fields : UnionField list
}
let getCases (SynTypeDefn.SynTypeDefn (_, repr, _, _, _, _)) : UnionCase list =
match repr with
| SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Union (_, cases, _), range0) ->
cases
|> List.map (fun (SynUnionCase.SynUnionCase (_, ident, kind, _, _, _, _)) ->
match kind with
| SynUnionCaseKind.FullType _ -> failwith "FullType union cases not supported"
| SynUnionCaseKind.Fields fields ->
{
Name = ident
Fields =
fields
|> List.map (fun (SynField.SynField (_, _, id, ty, _, _, _, _, _)) ->
{
Type = ty
Name = id
}
)
}
)
| _ -> failwithf "Failed to get union cases for type that was: %+A" repr
type FieldDescription =
| ListSelf of SynType
/// One of the union types itself
| Self of SynType
| NonRecursive of SynType
let analyse (allUnionTypes : SynTypeDefn list) (case : UnionCase) : FieldDescription list =
let rec go (ty : SynType) : FieldDescription =
let stripped = SynType.stripOptionalParen ty
match stripped with
| ListType child ->
let gone = go child
match gone with
| FieldDescription.NonRecursive ty -> FieldDescription.NonRecursive stripped
| FieldDescription.Self ty -> FieldDescription.ListSelf ty
| FieldDescription.ListSelf _ -> failwith "Deeply nested lists not currently supported"
| PrimitiveType _ -> NonRecursive stripped
| SynType.LongIdent (SynLongIdent.SynLongIdent (ty, _, _)) ->
let key = ty |> List.map _.idText |> String.concat "/"
let isSelf = allUnionTypes |> List.exists (fun unionTy -> getNameKey unionTy = key)
if isSelf then
FieldDescription.Self stripped
else
FieldDescription.NonRecursive stripped
| _ -> failwithf "Unrecognised type: %+A" stripped
case.Fields |> List.map _.Type |> List.map go
/// Returns whether this type recursively contains a Self, and the emitted TODO
let rec toInstructionCase (field : FieldDescription) : bool * SynType option =
match field with
| FieldDescription.NonRecursive ty -> false, Some ty
| FieldDescription.Self ty -> true, None
| FieldDescription.ListSelf ty ->
// store the length of the list
true, Some (SynType.Int ())
/// Given the input `| Pair of Expr * Expr * PairOpKind`,
/// strips out any members which contain recursive calls.
/// Stores a list as an int which is "the length of the list".
/// TODO: support other compound types.
let createInstructionCases (allUnionTypes : SynTypeDefn list) (case : UnionCase) : UnionField list option =
let analysed = analyse allUnionTypes case
let hasRecursion, cases =
((false, []), analysed)
||> List.fold (fun (hasRecursion, cases) field ->
let newHasRecursion, case = toInstructionCase field
let cases =
match case with
| None -> cases
| Some case -> case :: cases
hasRecursion || newHasRecursion, cases
)
if hasRecursion then
cases
|> List.rev
|> List.map (fun ty ->
{
Name = None
Type = ty
}
)
|> Some
else
None
let createInstructionType (allUnionTypes : SynTypeDefn list) : SynTypeDefn =
// One union case for each union type, and then
// a union case for each union case which contains a recursive reference.
let casesFromProcess : SynUnionCase list =
allUnionTypes
|> List.map (fun unionType ->
let name = getName unionType
SynUnionCase.Create (
Ident.Create ("Process" + (List.last name).idText),
[
SynField.Create (SynType.CreateLongIdent (SynLongIdent.CreateFromLongIdent name))
]
)
)
let casesFromCases =
allUnionTypes
|> List.collect (fun unionType ->
getCases unionType
|> List.choose (fun case ->
let fields = createInstructionCases allUnionTypes case
match fields with
| None -> None
| Some fields ->
let name =
match case.Name with
| SynIdent.SynIdent (ident, _) ->
(List.last (getName unionType)).idText + ident.idText |> Ident.Create
SynUnionCase.Create (name, fields |> List.map (fun field -> SynField.Create field.Type))
|> Some
)
)
let cases = casesFromProcess @ casesFromCases
SynTypeDefn.SynTypeDefn (
SynComponentInfo.SynComponentInfo (
[ SynAttributeList.Create [ SynAttribute.RequireQualifiedAccess () ] ],
None,
[],
[ Ident.Create "Instruction" ],
PreXmlDoc.Empty,
false,
Some (SynAccess.Private range0),
range0
),
SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Union (None, cases, range0), range0),
[],
None,
range0,
{
LeadingKeyword = SynTypeDefnLeadingKeyword.Type range0
EqualsRange = Some range0
WithKeyword = None
}
)
let createCataStructure (allUnionTypes : SynTypeDefn list) : SynTypeDefn list =
let generics =
allUnionTypes
|> List.map (fun defn ->
let name = getName defn |> List.map _.idText |> String.concat "" |> Ident.Create
SynTypar.SynTypar (name, TyparStaticReq.None, false)
)
let tyToGenericMap =
let names = allUnionTypes |> List.map getNameKey
List.zip names generics |> Map.ofList
allUnionTypes
|> List.map (fun unionType ->
let name =
match getName unionType |> List.rev with
| [] -> failwith "empty name"
| head :: rest -> Ident.Create (head.idText + "Cata") :: rest |> List.rev
let componentInfo =
let generics = generics |> List.map (fun ty -> SynTyparDecl.SynTyparDecl ([], ty))
SynComponentInfo.SynComponentInfo (
[],
Some (SynTyparDecls.PostfixList (generics, [], range0)),
[],
name,
// TODO: better docstring
PreXmlDoc.Create " Description of how to combine cases during a fold",
false,
None,
range0
)
let slots =
let ourGenericName = tyToGenericMap.[getNameKey unionType]
let flags =
{
SynMemberFlags.IsInstance = true
SynMemberFlags.IsDispatchSlot = true
SynMemberFlags.IsOverrideOrExplicitImpl = false
SynMemberFlags.IsFinal = false
SynMemberFlags.GetterOrSetterIsCompilerGenerated = false
SynMemberFlags.MemberKind = SynMemberKind.Member
}
getCases unionType
|> List.map (fun case ->
let caseName =
match case.Name with
| SynIdent.SynIdent (name, _) -> name
let arity =
SynValInfo.SynValInfo (
case.Fields |> List.map (fun field -> [ SynArgInfo.Empty ]),
SynArgInfo.Empty
)
let ty =
let analysed = analyse allUnionTypes case
(SynType.Var (ourGenericName, range0), List.rev analysed)
||> List.fold (fun acc field ->
let place : SynType =
match field with
| FieldDescription.Self ty ->
SynType.Var (tyToGenericMap.[getNameKeyUnion ty], range0)
| FieldDescription.ListSelf ty ->
SynType.CreateApp (
SynType.CreateLongIdent "list",
[ SynType.Var (tyToGenericMap.[getNameKeyUnion ty], range0) ],
true
)
| FieldDescription.NonRecursive ty -> ty
SynType.Fun (
place,
acc,
range0,
{
ArrowRange = range0
}
)
)
let slot =
SynValSig.SynValSig (
[],
case.Name,
SynValTyparDecls.SynValTyparDecls (None, true),
ty,
arity,
false,
false,
PreXmlDoc.Create $" How to operate on the %s{caseName.idText} case",
None,
None,
range0,
{
EqualsRange = None
WithKeyword = None
InlineKeyword = None
LeadingKeyword = SynLeadingKeyword.Abstract range0
}
)
SynMemberDefn.AbstractSlot (
slot,
flags,
range0,
{
GetSetKeywords = None
}
)
)
let repr = SynTypeDefnRepr.ObjectModel (SynTypeDefnKind.Unspecified, slots, range0)
SynTypeDefn.SynTypeDefn (
componentInfo,
repr,
[],
None,
range0,
{
LeadingKeyword = SynTypeDefnLeadingKeyword.Type range0
EqualsRange = Some range0
WithKeyword = None
}
)
)
let createCataRecord (allUnionTypes : SynTypeDefn list) : SynTypeDefn =
let nameForDoc = List.last (getName allUnionTypes.[0]) |> _.idText
let generics =
allUnionTypes
|> List.map (fun defn ->
let name = getName defn |> List.map _.idText |> String.concat "" |> Ident.Create
SynTypar.SynTypar (name, TyparStaticReq.None, false)
)
let fields =
allUnionTypes
|> List.map (fun unionType ->
let doc = PreXmlDoc.Create " TODO: doc"
let name = getName unionType
let ty =
SynType.App (
SynType.CreateLongIdent (SynLongIdent.CreateString (List.last(name).idText + "Cata")),
Some range0,
generics |> List.map (fun v -> SynType.Var (v, range0)),
List.replicate (generics.Length - 1) range0,
Some range0,
false,
range0
)
SynField.SynField (
[],
false,
Some (List.last name),
ty,
false,
doc,
None,
range0,
{
LeadingKeyword = None
}
)
)
let componentInfo =
SynComponentInfo.SynComponentInfo (
[],
Some (
SynTyparDecls.PostfixList (
generics |> List.map (fun ty -> SynTyparDecl.SynTyparDecl ([], ty)),
[],
range0
)
),
[],
[ Ident.Create "Cata" ], // TODO: better name
PreXmlDoc.Create $" Specifies how to perform a fold (catamorphism) over the type %s{nameForDoc}.",
false,
None,
range0
)
SynTypeDefn.SynTypeDefn (
componentInfo,
SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Record (None, fields, range0), range0),
[],
None,
range0,
{
LeadingKeyword = SynTypeDefnLeadingKeyword.Type range0
WithKeyword = None
EqualsRange = Some range0
}
)
let minusN (ident : SynLongIdent) (n : int) : SynExpr =
SynExpr.CreateApp (
SynExpr.CreateAppInfix (
SynExpr.CreateLongIdent (
SynLongIdent.SynLongIdent (
[ Ident.Create "op_Subtraction" ],
[],
[ Some (IdentTrivia.OriginalNotation "-") ]
)
),
SynExpr.CreateLongIdent ident
),
SynExpr.CreateConst (SynConst.Int32 n)
)
let createLoopFunction (allUnionTypes : SynTypeDefn list) : SynBinding =
let valData =
SynValData.SynValData (
None,
SynValInfo.SynValInfo (
[
[ SynArgInfo.SynArgInfo ([], false, Some (Ident.Create "cata")) ]
[ SynArgInfo.SynArgInfo ([], false, Some (Ident.Create "instructions")) ]
],
SynArgInfo.Empty
),
None
)
let headPat =
SynPat.LongIdent (
SynLongIdent.CreateString "loop",
None,
None,
SynArgPats.Pats
[
SynPat.CreateParen (
SynPat.CreateTyped (
SynPat.CreateNamed (Ident.Create "cata"),
SynType.App (
// TODO: better type name
SynType.CreateLongIdent "Cata",
Some range0,
List.replicate allUnionTypes.Length (SynType.Anon range0),
List.replicate (allUnionTypes.Length - 1) range0,
Some range0,
false,
range0
)
)
)
SynPat.CreateParen (
SynPat.CreateTyped (
SynPat.CreateNamed (Ident.Create "instructions"),
SynType.App (
SynType.CreateLongIdent "ResizeArray",
Some range0,
[ SynType.CreateLongIdent "Instruction" ],
[],
Some range0,
false,
range0
)
)
)
],
Some (SynAccess.Private range0),
range0
)
let stackNames =
allUnionTypes
|> List.map (fun ty ->
// TODO this is jank
List.last(getName ty).idText + "Stack" |> Ident.Create
)
let matchStatement =
SynExpr.CreateMatch (SynExpr.CreateIdentString "currentInstruction", [])
let body =
SynExpr.CreateSequential
[
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.Create [ "instructions" ; "RemoveAt" ]),
SynExpr.CreateParen (minusN (SynLongIdent.Create [ "instructions" ; "Count" ]) 1)
)
matchStatement
]
let body =
SynExpr.LetOrUse (
false,
false,
[
SynBinding.SynBinding (
None,
SynBindingKind.Normal,
false,
false,
[],
PreXmlDoc.Empty,
SynValData.SynValData (None, SynValInfo.SynValInfo ([], SynArgInfo.Empty), None),
SynPat.CreateNamed (Ident.Create "currentInstruction"),
None,
SynExpr.DotIndexedGet (
SynExpr.CreateIdentString "instructions",
minusN (SynLongIdent.Create [ "instructions" ; "Count" ]) 1,
range0,
range0
),
range0,
DebugPointAtBinding.Yes range0,
{
LeadingKeyword = SynLeadingKeyword.Let range0
InlineKeyword = None
EqualsRange = Some range0
}
)
],
body,
range0,
{
InKeyword = None
}
)
let body =
SynExpr.CreateSequential
[
SynExpr.While (
DebugPointAtWhile.Yes range0,
SynExpr.CreateApp (
SynExpr.CreateAppInfix (
SynExpr.CreateLongIdent (
SynLongIdent.SynLongIdent (
[ Ident.Create "op_GreaterThan" ],
[],
[ Some (IdentTrivia.OriginalNotation ">") ]
)
),
SynExpr.CreateLongIdent (SynLongIdent.Create [ "instructions" ; "Count" ])
),
SynExpr.CreateConst (SynConst.Int32 0)
),
body,
range0
)
SynExpr.CreateTuple (
stackNames
|> List.map (List.singleton >> SynLongIdent.CreateFromLongIdent >> SynExpr.CreateLongIdent)
)
]
let body =
(body, List.zip stackNames allUnionTypes)
||> List.fold (fun body (stackName, unionType) ->
SynExpr.LetOrUse (
false,
false,
[
SynBinding.SynBinding (
None,
SynBindingKind.Normal,
false,
false,
[],
PreXmlDoc.Empty,
SynValData.SynValData (None, SynValInfo.Empty, None),
SynPat.Named (SynIdent.SynIdent (stackName, None), false, None, range0),
None,
SynExpr.CreateApp (
SynExpr.CreateLongIdent (SynLongIdent.CreateString "ResizeArray"),
SynExpr.CreateConst SynConst.Unit
),
range0,
DebugPointAtBinding.Yes range0,
{
LeadingKeyword = SynLeadingKeyword.Let range0
InlineKeyword = None
EqualsRange = Some range0
}
)
],
body,
range0,
{
SynExprLetOrUseTrivia.InKeyword = None
}
)
)
SynBinding.SynBinding (
Some (SynAccess.Private range0),
SynBindingKind.Normal,
false,
false,
[],
PreXmlDoc.Empty,
valData,
headPat,
None,
body,
range0,
DebugPointAtBinding.NoneAtLet,
trivia =
{
LeadingKeyword = SynLeadingKeyword.Let range0
InlineKeyword = None
EqualsRange = Some range0
}
)
let createModule
(opens : SynOpenDeclTarget list)
(ns : LongIdent)
(taggedType : SynTypeDefn)
(allUnionTypes : SynTypeDefn list)
: SynModuleOrNamespace
=
let parentName = List.last (getName taggedType) |> _.idText
let moduleName : LongIdent = parentName + "Cata" |> Ident.Create |> List.singleton
let attribs = [ SynAttributeList.Create (SynAttribute.RequireQualifiedAccess ()) ]
let modInfo =
SynComponentInfo.Create (
moduleName,
attributes = attribs,
xmldoc = PreXmlDoc.Create $" Methods to perform a catamorphism over the type {parentName}"
)
let allTypars =
allUnionTypes
|> List.map (fun unionType ->
List.last (getName unionType)
|> fun x -> x.idText + "Ret"
|> Ident.Create
|> fun x -> SynTypar.SynTypar (x, TyparStaticReq.None, false)
|> fun x -> SynType.Var (x, range0)
)
let runFunctions =
List.zip allUnionTypes allTypars
|> List.map (fun (unionType, relevantTypar) -> createRunFunction allTypars relevantTypar unionType)
let cataStructures =
createCataStructure allUnionTypes
|> List.map (fun repr -> SynModuleDecl.Types ([ repr ], range0))
let loopFunction = createLoopFunction allUnionTypes
let cataRecord = SynModuleDecl.Types ([ createCataRecord allUnionTypes ], range0)
SynModuleOrNamespace.CreateNamespace (
ns,
decls =
[
for openStatement in opens do
yield SynModuleDecl.CreateOpen openStatement
yield! cataStructures
yield cataRecord
yield
SynModuleDecl.CreateNestedModule (
modInfo,
[
SynModuleDecl.Types ([ createInstructionType allUnionTypes ], range0)
SynModuleDecl.CreateLet (loopFunction :: runFunctions)
]
)
]
)
/// Myriad generator that provides an HTTP client for an interface type using RestEase annotations.
[<MyriadGenerator("create-catamorphism")>]
type CreateCatamorphismGenerator () =
interface IMyriadGenerator with
member _.ValidInputExtensions = [ ".fs" ]
member _.Generate (context : GeneratorContext) =
let ast, _ =
Ast.fromFilename context.InputFilename |> Async.RunSynchronously |> Array.head
let types = Ast.extractTypeDefn ast
let opens = AstHelper.extractOpens ast
let namespaceAndTypes =
types
|> List.choose (fun (ns, types) ->
match types |> List.tryFind Ast.hasAttribute<CreateCatamorphismAttribute> with
| Some taggedType ->
let anyNonUnion =
types
|> List.exists (fun (SynTypeDefn.SynTypeDefn (_, repr, _, _, _, _)) ->
match repr with
| SynTypeDefnRepr.Simple (SynTypeDefnSimpleRepr.Union _, _) -> false
| _ -> true
)
if anyNonUnion then
failwith
"Error: all types recursively defined together with a CreateCatamorphism type must be discriminated unions"
Some (ns, taggedType, types)
| _ -> None
)
let modules =
namespaceAndTypes
|> List.map (fun (ns, taggedType, types) -> CataGenerator.createModule opens ns taggedType types)
Output.Ast modules