// create a function value
// BUG: a persistent function must not reference a non-persistent global
public AstValue Funval(AstType rettype, IList <AstField> arguments, AstBodyStatement body)
{
var code = Code(body.Statement as AstValue, Headingof(arguments), "λ", false, body.AccumCount, body.HasWin);
return(new AstFunval {
Value = code, DataType = DataTypeCode.Get(code.DataType, code.Lookup)
});
}
// finalise function definition, from basic definition previously created
// set or check return type
// null body just defines type
// Note: null arguments means argless (lazy) rather than deffun
// BUG: a persistent function must not reference a non-persistent global
public AstStatement Deffun(string ident, AstType rettype, IList <AstField> arguments, AstBodyStatement body)
{
var op = FindDefFunc(ident);
var callinfo = op.CallInfo;
if (callinfo.ReturnType == DataTypes.Unknown)
{
callinfo.ReturnType = body.DataType;
}
else if (callinfo.ReturnType != body.DataType)
{
Parser.ParseError($"{ident} return type mismatch");
}
if (op.DataType == DataTypes.Unknown)
{
if (arguments == null)
{
op.DataType = callinfo.ReturnType;
}
}
else if (op.DataType != callinfo.ReturnType)
{
Parser.ParseError("body does not match declared type");
}
// assume top overload is the one being defined
//op.callinfo.ReturnType = op.DataType;
callinfo.AccumCount = body.AccumCount;
callinfo.HasWin = body.HasWin;
// symbol is foldable if all overloads are foldable
// FIX: put this test where it's used
var foldable = (callinfo.NumArgs == 2 && arguments[0].DataType == callinfo.ReturnType && arguments[1].DataType == callinfo.ReturnType) &&
(callinfo.OverLoad == null || op.IsFoldable);
if (foldable && !op.IsFoldable)
{
op.Foldable = FoldableFlags.ANY;
}
Symbols.AddCatalog(op);
// assemble node
var code = Code(body.Statement as AstValue, Headingof(arguments), callinfo.Name, true, body.AccumCount, body.HasWin);
return(GenFunCall(FindFunc(SymNames.Defer), Args(code)));
}