Files
MycLib/Src/AST/Myc.Ast.Compiler.TypeChecker.pas
T
2025-12-26 13:47:10 +01:00

881 lines
29 KiB
ObjectPascal

unit Myc.Ast.Compiler.TypeChecker;
interface
uses
System.SysUtils,
System.Classes,
System.Generics.Collections,
Myc.Data.Scalar,
Myc.Data.Value,
Myc.Ast.Nodes,
Myc.Ast.Visitor,
Myc.Ast.Scope,
Myc.Ast.Types,
Myc.Ast.Identities,
Myc.Ast;
type
IAstTypeChecker = interface(IAstVisitor)
function Execute(const RootNode: IAstNode): IAstNode;
end;
TTypeChecker = class(TAstTransformer, IAstTypeChecker)
private
type
TTypeContext = class
private
FParent: TTypeContext;
FLayout: IScopeLayout;
FSlotTypes: TArray<IStaticType>;
FUpvalueTypes: TArray<IStaticType>;
public
constructor Create(
AParent: TTypeContext;
ALayout: IScopeLayout;
const AUpvalueTypes: TArray<IStaticType>;
ADescriptor: IScopeDescriptor
);
function LookupType(const Address: TResolvedAddress): IStaticType;
procedure SetType(SlotIndex: Integer; AType: IStaticType);
property Types: TArray<IStaticType> read FSlotTypes;
end;
private
FCurrentContext: TTypeContext;
FLog: ICompilerLog;
FRootScope: IExecutionScope;
function CreateContextChain(L: IScopeLayout): TTypeContext;
// Helpers for Null Propagation
function PrepareBaseType(const BaseNode: IAstNode; out IsOptional: Boolean): IStaticType;
function ApplyOptionality(const AType: IStaticType; IsOptional: Boolean): IStaticType;
protected
function VisitIdentifier(const Node: IIdentifierNode): IAstNode; override;
function VisitVariableDeclaration(const Node: IVariableDeclarationNode): IAstNode; override;
function VisitAssignment(const Node: IAssignmentNode): IAstNode; override;
function VisitLambdaExpression(const Node: ILambdaExpressionNode): IAstNode; override;
function VisitFunctionCall(const Node: IFunctionCallNode): IAstNode; override;
function VisitBlockExpression(const Node: IBlockExpressionNode): IAstNode; override;
function VisitIfExpression(const Node: IIfExpressionNode): IAstNode; override;
function VisitMemberAccess(const Node: IMemberAccessNode): IAstNode; override;
function VisitIndexer(const Node: IIndexerNode): IAstNode; override;
function VisitCreateSeries(const Node: ICreateSeriesNode): IAstNode; override;
function VisitSeriesLength(const Node: ISeriesLengthNode): IAstNode; override;
function VisitRecurNode(const Node: IRecurNode): IAstNode; override;
function VisitNop(const Node: INopNode): IAstNode; override;
function VisitRecordLiteral(const Node: IRecordLiteralNode): IAstNode; override;
function VisitConstant(const Node: IConstantNode): IAstNode; override;
function VisitKeyword(const Node: IKeywordNode): IAstNode; override;
// Pipe Support
function VisitPipeInput(const Node: IPipeInputNode): IAstNode; override;
function VisitPipe(const Node: IPipeNode): IAstNode; override;
public
constructor Create(const RootLayout: IScopeLayout; const RootScope: IExecutionScope; const ALog: ICompilerLog);
destructor Destroy; override;
function Execute(const RootNode: IAstNode): IAstNode;
class function CheckTypes(
const RootNode: IAstNode;
const Layout: IScopeLayout;
const RootScope: IExecutionScope;
const ALog: ICompilerLog
): IAstNode; static;
end;
implementation
uses
System.Generics.Defaults,
Myc.Data.Keyword;
{ TTypeChecker.TTypeContext }
constructor TTypeChecker.TTypeContext.Create(
AParent: TTypeContext;
ALayout: IScopeLayout;
const AUpvalueTypes: TArray<IStaticType>;
ADescriptor: IScopeDescriptor
);
var
i: Integer;
begin
inherited Create;
FParent := AParent;
FLayout := ALayout;
FUpvalueTypes := AUpvalueTypes;
if Assigned(FLayout) then
begin
SetLength(FSlotTypes, FLayout.SlotCount);
if Assigned(ADescriptor) then
begin
// Load known types from descriptor (e.g. for Root Scope / RTL)
for i := 0 to High(FSlotTypes) do
FSlotTypes[i] := ADescriptor.GetSymbolType(i);
end
else
begin
// Initialize with Unknown for new scopes
for i := 0 to High(FSlotTypes) do
FSlotTypes[i] := TTypes.Unknown;
end;
end;
end;
function TTypeChecker.TTypeContext.LookupType(const Address: TResolvedAddress): IStaticType;
var
ctx: TTypeContext;
i: Integer;
begin
case Address.Kind of
akLocalOrParent:
begin
ctx := Self;
for i := 1 to Address.ScopeDepth do
begin
if not Assigned(ctx.FParent) then
begin
Result := TTypes.Unknown;
Exit;
end;
ctx := ctx.FParent;
end;
if (Address.SlotIndex >= 0) and (Address.SlotIndex < Length(ctx.FSlotTypes)) then
Result := ctx.FSlotTypes[Address.SlotIndex]
else
Result := TTypes.Unknown;
end;
akUpvalue:
begin
if (Address.SlotIndex >= 0) and (Address.SlotIndex < Length(FUpvalueTypes)) then
Result := FUpvalueTypes[Address.SlotIndex]
else
Result := TTypes.Unknown;
end;
else
Result := TTypes.Unknown;
end;
end;
procedure TTypeChecker.TTypeContext.SetType(SlotIndex: Integer; AType: IStaticType);
begin
if (SlotIndex >= 0) and (SlotIndex < Length(FSlotTypes)) then
FSlotTypes[SlotIndex] := AType;
end;
{ TTypeChecker }
function TTypeChecker.CreateContextChain(L: IScopeLayout): TTypeContext;
var
p: TTypeContext;
desc: IScopeDescriptor;
begin
if L = nil then
exit(nil);
p := CreateContextChain(L.Parent);
desc := nil;
if (L.Parent = nil) and Assigned(FRootScope) then
begin
desc := FRootScope.Descriptor;
end;
Result := TTypeContext.Create(p, L, [], desc);
end;
constructor TTypeChecker.Create(const RootLayout: IScopeLayout; const RootScope: IExecutionScope; const ALog: ICompilerLog);
begin
inherited Create;
FLog := ALog;
FRootScope := RootScope;
FCurrentContext := CreateContextChain(RootLayout);
if FCurrentContext = nil then
FCurrentContext := TTypeContext.Create(nil, nil, [], nil);
end;
destructor TTypeChecker.Destroy;
begin
while Assigned(FCurrentContext) do
begin
var temp := FCurrentContext;
FCurrentContext := FCurrentContext.FParent;
temp.Free;
end;
inherited;
end;
class function TTypeChecker.CheckTypes(
const RootNode: IAstNode;
const Layout: IScopeLayout;
const RootScope: IExecutionScope;
const ALog: ICompilerLog
): IAstNode;
var
startLayout: IScopeLayout;
begin
if Assigned(Layout) then
startLayout := Layout.Parent
else
startLayout := nil;
var checker := TTypeChecker.Create(startLayout, RootScope, ALog) as IAstTypeChecker;
Result := checker.Execute(RootNode);
end;
function TTypeChecker.Execute(const RootNode: IAstNode): IAstNode;
begin
Result := Accept(RootNode);
if not Assigned(Result) then
Result := TAst.Block([], nil);
end;
// --- Helper ---
function TTypeChecker.PrepareBaseType(const BaseNode: IAstNode; out IsOptional: Boolean): IStaticType;
var
baseType: IStaticType;
begin
baseType := BaseNode.AsTypedNode.StaticType;
IsOptional := baseType.IsOptional;
Result := TTypes.Unwrap(baseType);
end;
function TTypeChecker.ApplyOptionality(const AType: IStaticType; IsOptional: Boolean): IStaticType;
begin
if IsOptional and (AType.Kind <> stUnknown) then
Result := TTypes.MakeOptional(AType)
else
Result := AType;
end;
// --- Visits ---
function TTypeChecker.VisitConstant(const Node: IConstantNode): IAstNode;
begin
Result := Node;
end;
function TTypeChecker.VisitKeyword(const Node: IKeywordNode): IAstNode;
begin
Result := Node;
end;
function TTypeChecker.VisitIdentifier(const Node: IIdentifierNode): IAstNode;
var
typ: IStaticType;
adr: TResolvedAddress;
identity: INamedIdentity;
begin
adr := Node.Address;
identity := Node.Identity.AsNamed;
if adr.Kind = akUnresolved then
begin
Result := TAst.Identifier(identity, adr, TTypes.Unknown);
Exit;
end;
typ := FCurrentContext.LookupType(adr);
Result := TAst.Identifier(identity, adr, typ);
end;
function TTypeChecker.VisitRecurNode(const Node: IRecurNode): IAstNode;
var
newArgs: TArray<IAstNode>;
i: Integer;
begin
SetLength(newArgs, Node.Arguments.Count);
for i := 0 to Node.Arguments.Count - 1 do
newArgs[i] := Accept(Node.Arguments[i]);
var argList := TArgumentList.Create(newArgs, Node.Arguments.Identity);
Result := TAst.Recur(Node.Identity, argList, TTypes.Void);
end;
function TTypeChecker.VisitVariableDeclaration(const Node: IVariableDeclarationNode): IAstNode;
var
initType: IStaticType;
newInitializer, newIdent: IAstNode;
adr: TResolvedAddress;
identNode: IIdentifierNode;
begin
identNode := Node.Target.AsIdentifier;
adr := identNode.Address;
initType := TTypes.Unknown;
if adr.Kind = akUnresolved then
begin
if Assigned(Node.Initializer) then
Accept(Node.Initializer);
Result := Node;
Exit;
end;
if Assigned(Node.Initializer) then
newInitializer := Accept(Node.Initializer)
else
newInitializer := nil;
if Assigned(newInitializer) then
initType := newInitializer.AsTypedNode.StaticType;
if initType.Kind <> stUnknown then
FCurrentContext.SetType(adr.SlotIndex, initType);
newIdent := TAst.Identifier(identNode.Identity.AsNamed, adr, initType);
Result := TAst.VarDecl(Node.Identity, newIdent, newInitializer, initType, Node.IsBoxed);
end;
function TTypeChecker.VisitAssignment(const Node: IAssignmentNode): IAstNode;
var
targetType, sourceType: IStaticType;
newIdent, newValue: IAstNode;
adr: TResolvedAddress;
identNode: IIdentifierNode;
begin
identNode := Node.Target.AsIdentifier;
newIdent := Accept(Node.Target);
targetType := newIdent.AsTypedNode.StaticType;
adr := identNode.Address;
if adr.Kind = akUnresolved then
begin
Accept(Node.Value);
Result := Node;
Exit;
end;
newValue := Accept(Node.Value);
sourceType := newValue.AsTypedNode.StaticType;
if (targetType.Kind <> stUnknown) and (sourceType.Kind <> stUnknown) then
begin
if not TTypeRules.CanAssign(targetType, sourceType) then
begin
if Assigned(FLog) then
FLog.AddError(Format('Cannot assign type %s to %s', [sourceType.ToString, targetType.ToString]), Node);
end;
end;
if (targetType.Kind = stUnknown) and (sourceType.Kind <> stUnknown) then
begin
FCurrentContext.SetType(adr.SlotIndex, sourceType);
newIdent := TAst.Identifier(identNode.Identity.AsNamed, adr, sourceType);
targetType := sourceType;
end;
Result := TAst.Assign(Node.Identity, newIdent, newValue, targetType);
end;
function TTypeChecker.VisitBlockExpression(const Node: IBlockExpressionNode): IAstNode;
var
blockType: IStaticType;
newExprs: TArray<IAstNode>;
i: Integer;
begin
SetLength(newExprs, Node.Expressions.Count);
for i := 0 to Node.Expressions.Count - 1 do
newExprs[i] := Accept(Node.Expressions[i]);
if Length(newExprs) > 0 then
blockType := newExprs[High(newExprs)].AsTypedNode.StaticType
else
blockType := TTypes.Void;
var exprList := TExpressionList.Create(newExprs, Node.Expressions.Identity);
Result := TAst.Block(Node.Identity, exprList, blockType);
end;
function TTypeChecker.VisitLambdaExpression(const Node: ILambdaExpressionNode): IAstNode;
var
newParams: TArray<IIdentifierNode>;
newBody: IAstNode;
bodyType, methodType: IStaticType;
paramTypes: TArray<IStaticType>;
upvalueTypes: TArray<IStaticType>;
i: Integer;
finalDescriptor: IScopeDescriptor;
paramIdent: IIdentifierNode;
injectedType: IStaticType;
begin
// 1. Resolve Upvalue Types
var upvalueAddrs := Node.Upvalues;
SetLength(upvalueTypes, Length(upvalueAddrs));
for i := 0 to High(upvalueAddrs) do
begin
var lookupAddr := upvalueAddrs[i];
if lookupAddr.Kind = akLocalOrParent then
begin
if lookupAddr.ScopeDepth > 0 then
Dec(lookupAddr.ScopeDepth);
end;
upvalueTypes[i] := FCurrentContext.LookupType(lookupAddr);
end;
// 2. Enter New Scope
FCurrentContext := TTypeContext.Create(FCurrentContext, Node.Layout, upvalueTypes, nil);
try
SetLength(newParams, Node.Parameters.Count);
SetLength(paramTypes, Node.Parameters.Count);
for i := 0 to Node.Parameters.Count - 1 do
begin
paramIdent := Node.Parameters[i];
// Check if there is already a type assigned (e.g. injected by Pipe Visitor)
injectedType := paramIdent.AsTypedNode.StaticType;
if injectedType.Kind = stUnknown then
paramTypes[i] := TTypes.Unknown
else
paramTypes[i] := injectedType;
if paramIdent.Address.Kind <> akUnresolved then
FCurrentContext.SetType(paramIdent.Address.SlotIndex, paramTypes[i]);
newParams[i] := TAst.Identifier(paramIdent.Identity.AsNamed, paramIdent.Address, paramTypes[i]);
end;
newBody := Accept(Node.Body);
bodyType := newBody.AsTypedNode.StaticType;
methodType := TTypes.CreateMethod(paramTypes, bodyType);
finalDescriptor := TScope.CreateDescriptor(Node.Layout, FCurrentContext.Types);
finally
var temp := FCurrentContext;
FCurrentContext := FCurrentContext.FParent;
temp.Free;
end;
var paramList := TParameterList.Create(newParams, Node.Parameters.Identity);
Result :=
TAst.LambdaExpr(
Node.Identity,
paramList,
newBody,
Node.Layout,
finalDescriptor,
Node.Upvalues,
Node.HasNestedLambdas,
Node.IsPure,
methodType
);
end;
function TTypeChecker.VisitFunctionCall(const Node: IFunctionCallNode): IAstNode;
var
calleeType, retType: IStaticType;
i, j: Integer;
newCallee: IAstNode;
newArgs: TArray<IAstNode>;
argTypes: TArray<IStaticType>;
hasUnknownArgs: Boolean;
bestSig: IMethodSignature;
match: Boolean;
begin
newCallee := Accept(Node.Callee);
SetLength(newArgs, Node.Arguments.Count);
SetLength(argTypes, Node.Arguments.Count);
hasUnknownArgs := False;
for i := 0 to Node.Arguments.Count - 1 do
begin
newArgs[i] := Accept(Node.Arguments[i]);
argTypes[i] := newArgs[i].AsTypedNode.StaticType;
if argTypes[i].Kind = stUnknown then
hasUnknownArgs := True;
end;
calleeType := newCallee.AsTypedNode.StaticType;
retType := TTypes.Unknown;
if calleeType.Kind = stMethod then
begin
if not hasUnknownArgs then
begin
bestSig := nil;
for var sig in calleeType.Signatures do
begin
if Length(sig.ParamTypes) <> Length(argTypes) then
continue;
match := True;
for j := 0 to High(argTypes) do
if not TTypeRules.CanAssign(sig.ParamTypes[j], argTypes[j]) then
begin
match := False;
break;
end;
if match then
begin
bestSig := sig;
break;
end;
end;
if Assigned(bestSig) then
retType := bestSig.ReturnType
else if Assigned(FLog) then
FLog.AddError(Format('No matching signature found for method call on %s', [calleeType.ToString]), Node);
end;
end
else if calleeType.Kind <> stUnknown then
if Assigned(FLog) then
FLog.AddError(Format('Cannot invoke type %s as a function.', [calleeType.ToString]), Node);
var argList := TArgumentList.Create(newArgs, Node.Arguments.Identity);
Result := TAst.FunctionCall(Node.Identity, newCallee, argList, retType, Node.IsTailCall, nil, False);
end;
function TTypeChecker.VisitIfExpression(const Node: IIfExpressionNode): IAstNode;
var
newCond, newThen, newElse: IAstNode;
resType: IStaticType;
begin
newCond := Accept(Node.Condition);
newThen := Accept(Node.ThenBranch);
newElse := Accept(Node.ElseBranch);
// Simple promotion logic
if (newElse <> nil) then
resType := TTypeRules.Promote(newThen.AsTypedNode.StaticType, newElse.AsTypedNode.StaticType)
else
resType := TTypes.MakeOptional(newThen.AsTypedNode.StaticType);
Result := TAst.IfExpr(Node.Identity, newCond, newThen, newElse, resType);
end;
function TTypeChecker.VisitIndexer(const Node: IIndexerNode): IAstNode;
var
newBase, newIndex: IAstNode;
baseType, elemType: IStaticType;
isOpt: Boolean;
begin
newBase := Accept(Node.Base);
newIndex := Accept(Node.Index);
baseType := PrepareBaseType(newBase, isOpt);
elemType := TTypes.Unknown;
if baseType.Kind = stSeries then
elemType := baseType.ElementType
else if baseType.Kind = stRecordSeries then
elemType := TTypes.CreateRecord(baseType.Definition);
elemType := ApplyOptionality(elemType, isOpt);
Result := TAst.Indexer(Node.Identity, newBase, newIndex, elemType);
end;
function TTypeChecker.VisitMemberAccess(const Node: IMemberAccessNode): IAstNode;
var
newBase: IAstNode;
baseType, resType: IStaticType;
idx: Integer;
isOpt: Boolean;
begin
newBase := Accept(Node.Base);
baseType := PrepareBaseType(newBase, isOpt);
resType := TTypes.Unknown;
if (baseType.Kind = stRecord) or (baseType.Kind = stRecordSeries) then
begin
idx := baseType.Definition.IndexOf(Node.Member.Value);
if idx >= 0 then
begin
var fieldType := TTypes.FromScalarKind(baseType.Definition.Items[idx].Value);
if baseType.Kind = stRecordSeries then
resType := TTypes.CreateSeries(fieldType)
else
resType := fieldType;
end
else if Assigned(FLog) then
FLog.AddError('Member not found', Node);
end;
resType := ApplyOptionality(resType, isOpt);
Result := TAst.MemberAccess(Node.Identity, newBase, Node.Member, resType);
end;
function TTypeChecker.VisitRecordLiteral(const Node: IRecordLiteralNode): IAstNode;
var
i: Integer;
newFields: TArray<IRecordFieldNode>;
fieldTypes: TArray<TPair<IKeyword, IStaticType>>;
scalarFieldTypes: TArray<TPair<IKeyword, TScalar.TKind>>;
isScalar: Boolean;
valType: IStaticType;
key: IKeyword;
visitedValue: IAstNode;
newFieldList: IRecordFieldList;
begin
SetLength(newFields, Node.Fields.Count);
SetLength(fieldTypes, Node.Fields.Count);
SetLength(scalarFieldTypes, Node.Fields.Count);
isScalar := True;
for i := 0 to Node.Fields.Count - 1 do
begin
var oldField := Node.Fields[i];
visitedValue := Accept(oldField.Value);
// Keys are guaranteed to be keywords by parser
key := oldField.Key.Value;
// Recreate the field node with the typed value
newFields[i] := TAst.RecordField(oldField.Identity, oldField.Key, visitedValue);
// Analyze Type
valType := visitedValue.AsTypedNode.StaticType;
// Check if strict scalar (no optionals allowed in packed ScalarRecord)
if (valType.Kind in [stOrdinal, stFloat, stBoolean, stDateTime, stKeyword]) and (not valType.IsOptional) then
begin
var kind: TScalar.TKind;
// Map StaticType Kind to Scalar Kind
case valType.Kind of
stOrdinal: kind := TScalar.TKind.Ordinal;
stFloat: kind := TScalar.TKind.Float;
stBoolean: kind := TScalar.TKind.Boolean;
stDateTime: kind := TScalar.TKind.DateTime;
stKeyword: kind := TScalar.TKind.Keyword;
else
kind := TScalar.TKind.Ordinal; // Should not happen given check above
end;
scalarFieldTypes[i] := TPair<IKeyword, TScalar.TKind>.Create(key, kind);
end
else
begin
isScalar := False;
end;
fieldTypes[i] := TPair<IKeyword, IStaticType>.Create(key, valType);
end;
// Build Definition
var scalarDef: IScalarRecordDefinition := nil;
var genericDef: IGenericRecordDefinition := nil;
var resultType: IStaticType;
if isScalar and (Length(newFields) > 0) then
begin
scalarDef := TKeywordMappingRegistry<TScalar.TKind>.Intern(scalarFieldTypes);
resultType := TTypes.CreateRecord(scalarDef);
end
else
begin
genericDef := TGenericRecordRegistry.Intern(fieldTypes);
resultType := TTypes.CreateGenericRecord(genericDef);
end;
newFieldList := TRecordFieldList.Create(newFields, Node.Fields.Identity);
Result := TAst.RecordLiteral(Node.Identity, newFieldList, scalarDef, genericDef, resultType);
end;
function TTypeChecker.VisitCreateSeries(const Node: ICreateSeriesNode): IAstNode;
var
elemType: IStaticType;
def: string;
begin
def := Node.Definition;
// Simple heuristic for type
if def.StartsWith('[') then
elemType := TTypes.CreateRecord(nil) // Placeholder, normally parses JSON
else
elemType := TTypes.FromScalarKind(TScalar.StringToKind(def));
Result := TAst.CreateSeries(Node.Identity.AsDefinition, TTypes.CreateSeries(elemType));
end;
function TTypeChecker.VisitSeriesLength(const Node: ISeriesLengthNode): IAstNode;
begin
Result := TAst.SeriesLength(Node.Identity, Accept(Node.Series).AsIdentifier, TTypes.Ordinal);
end;
function TTypeChecker.VisitNop(const Node: INopNode): IAstNode;
begin
Result := TAst.Nop(Node.Identity, TTypes.Void);
end;
// =============================================================================
// PIPE IMPLEMENTATION (Type Checking)
// =============================================================================
function TTypeChecker.VisitPipeInput(const Node: IPipeInputNode): IAstNode;
var
newSource: IIdentifierNode;
sourceType: IStaticType;
newSelectors: TArray<IKeywordNode>;
i: Integer;
begin
newSource := Accept(Node.StreamSource).AsIdentifier;
sourceType := newSource.AsTypedNode.StaticType;
// 1. Verify Source is a Series-compatible type
if (sourceType.Kind <> stUnknown) then
begin
if not ((sourceType.Kind = stSeries) or (sourceType.Kind = stRecordSeries)) then
begin
if Assigned(FLog) then
FLog.AddError(
Format('Pipe input "%s" must be a Series or RecordSeries, but got %s.', [newSource.Name, sourceType.ToString]),
Node
);
end
else if (sourceType.Kind = stRecordSeries) then
begin
// 2. Verify Selectors exist in Record Definition
var def := sourceType.Definition;
for var sel in Node.Selectors do
begin
if def.IndexOf(sel.Value) < 0 then
begin
if Assigned(FLog) then
FLog.AddError(Format('Field ":%s" not found in stream "%s".', [sel.Value.Name, newSource.Name]), sel);
end;
end;
end;
end;
// Reconstruct list simply to pass through
SetLength(newSelectors, Node.Selectors.Count);
for i := 0 to Node.Selectors.Count - 1 do
newSelectors[i] := Node.Selectors[i];
Result := TAst.PipeInput(newSource, TAst.PipeSelectorList(newSelectors, Node.Selectors.Identity.Location), Node.Identity.Location);
end;
function TTypeChecker.VisitPipe(const Node: IPipeNode): IAstNode;
var
i, k: Integer;
inputNode: IPipeInputNode;
newInputs: TArray<IPipeInputNode>;
streamType: IStaticType;
paramTypes: TList<IStaticType>;
lambda: ILambdaExpressionNode;
newParams: TArray<IIdentifierNode>;
inferredType: IStaticType;
begin
SetLength(newInputs, Node.Inputs.Count);
paramTypes := TList<IStaticType>.Create;
try
// 1. Visit Inputs and collect types for Lambda parameters
for i := 0 to Node.Inputs.Count - 1 do
begin
inputNode := Accept(Node.Inputs[i]).AsPipeInput;
newInputs[i] := inputNode;
streamType := inputNode.StreamSource.AsTypedNode.StaticType;
// Flatten logic: One lambda param per selector
for var sel in inputNode.Selectors do
begin
inferredType := TTypes.Unknown;
if streamType.Kind = stRecordSeries then
begin
// Extract field type from definition
var def := streamType.Definition;
var idx := def.IndexOf(sel.Value);
if idx >= 0 then
inferredType := TTypes.FromScalarKind(def.Items[idx].Value);
end
else if streamType.Kind = stSeries then
begin
// If simple series, use its element type
if Assigned(streamType.ElementType) then
inferredType := streamType.ElementType
else
inferredType := TTypes.Ordinal; // Fallback default
end;
paramTypes.Add(inferredType);
end;
end;
// 2. Prepare Lambda with Inferred Types
lambda := Node.Transformation;
if lambda.Parameters.Count <> paramTypes.Count then
begin
if Assigned(FLog) then
FLog.AddError(
Format(
'Pipe lambda expects %d parameters (one per selector), but got %d.',
[paramTypes.Count, lambda.Parameters.Count]
),
lambda
);
end;
SetLength(newParams, lambda.Parameters.Count);
for k := 0 to lambda.Parameters.Count - 1 do
begin
var oldP := lambda.Parameters[k];
var typeToInject :=
if k < paramTypes.Count then paramTypes[k]
else TTypes.Unknown;
// Create new identifier with the inferred type!
newParams[k] := TAst.Identifier(oldP.Identity.AsNamed, oldP.Address, typeToInject);
end;
// Recreate Lambda NODE with Typed Parameters
var preTypedLambda :=
TAst.LambdaExpr(
lambda.Identity,
TParameterList.Create(newParams, lambda.Parameters.Identity),
lambda.Body,
lambda.Layout,
lambda.Descriptor,
lambda.Upvalues,
lambda.HasNestedLambdas,
lambda.IsPure,
TTypes.Unknown // Will be recalculated in Accept
);
// 3. Visit the Lambda (This will now type-check the Body using the types we just injected)
var typedLambda := Accept(preTypedLambda).AsLambdaExpression;
// 4. Infer Pipe Return Type & Validate Strictness
var lambdaRetType := typedLambda.AsTypedNode.StaticType.Signatures[0].ReturnType;
var pipeType: IStaticType;
if lambdaRetType.Kind = stRecord then
begin
// Valid: Record -> RecordSeries
pipeType := TTypes.CreateRecordSeries(lambdaRetType.Definition);
end
else
begin
// STRICT CHECK: Scalars are NOT allowed.
if (lambdaRetType.Kind <> stUnknown) and (lambdaRetType.Kind <> stVoid) then
begin
if Assigned(FLog) then
FLog.AddError(
Format('Pipe function must return a Record (e.g. {:res ...}). Type "%s" is invalid.', [lambdaRetType.ToString]),
lambda
);
end;
// If Void or Unknown, or Error case:
pipeType := TTypes.Unknown;
end;
Result := TAst.Pipe(Node.Identity, TPipeInputList.Create(newInputs, Node.Inputs.Identity), typedLambda, pipeType);
finally
paramTypes.Free;
end;
end;
end.