private static Type getFun(SymbolTable stable, CommonTree funId, List<Type> argTypes)
{
String sym = funId.Text;
int line = funId.Line;
if (!stable.exists(sym))
{
error(line, "function '" + sym + "' does not exist");
return null;
}
Type fType = stable.getType(sym);
if (!fType.isFun())
{
error(line, "'" + sym + "' is not a function");
return null;
}
List<Type> formals = fType.getArgs();
if (formals.Count != argTypes.Count)
{
error(line, "argument number mis-match when calling '" + sym + "' (need " + formals.Count + ", have " + argTypes.Count + ")");
return null;
}
for (int i = 0; i < formals.Count; i++)
{
Type t1, t2;
t1 = formals[i];
t2 = argTypes[i];
if (!t1.canAssign(t2))
{
error(line, "arg " + i + " to function '" + sym + "' is not right");
return null;
}
}
return fType.getReturnType();
}
public static TransformStep<Tuple<CommonTokenStream, CommonTree>> TypeCheck()
{
return new TransformStep<Tuple<CommonTokenStream, CommonTree>>(t =>
{
CommonTreeNodeStream nodes = new CommonTreeNodeStream(t.Item2);
nodes.TokenStream = t.Item1;
TypeChecker tparser = new TypeChecker(nodes);
tparser.TraceDestination = Console.Out;
StructTypes stypes = new StructTypes();
SymbolTable stable = new SymbolTable();
Program.Stypes.Value = stypes;
Program.Stable.Value = stable;
tparser.Program(stypes, stable);
if (tparser.NumberOfSyntaxErrors != 0)
throw new EvilException(EvilSystem.Typecheck, "Type check tree walking errors.");
return t;
});
}
public SymbolTable(SymbolTable parent)
{
this.parent = parent;
this.parent.children.Add(this);
}
public void Program(StructTypes stypes, SymbolTable stable)
{
this.program(stypes, stable);
}
private static Type getVar(SymbolTable stable, CommonTree sym)
{
if (stable.exists(sym.Text))
{
Type t = stable.getType(sym.Text);
if (t.isFun())
error(sym.Line, "sym '" + sym.Text + "' is a fun and that does not fly");
return t;
}
error(sym.Line, "could not find symbol '" + sym.Text + "'");
return null;
}