MODULE TAst;
// Stage-A self-test for the AST module: build a small tree and walk it.
// Prints "ok=<n>"; exit 42 when all 10 checks pass.
IMPORT AST, FileIO;

VAR ExitCode : INTEGER;
VAR root, e1, e2, e3 : AST.Node;
VAR s : ARRAY [0..63] OF CHAR;
VAR ok : INTEGER;

BEGIN
  ok := 0;
  AST.Init;

  e2 := AST.MakeLeaf(AST.NkIdent, "b");
  e3 := AST.MakeLeaf(AST.NkIntLit, "2");
  e1 := AST.MakeBin(AST.NkBinExpr, AST.OpAdd, e2, e3);
  root := AST.MakeBin(AST.NkAssign, 0,
             AST.MakeLeaf(AST.NkIdent, "a"), e1);

  IF AST.Kind(root) = AST.NkAssign THEN INC(ok) END;
  IF AST.NChild(root) = 2 THEN INC(ok) END;
  IF AST.Kind(AST.Child(root, 0)) = AST.NkIdent THEN INC(ok) END;
  IF AST.Kind(AST.Child(root, 1)) = AST.NkBinExpr THEN INC(ok) END;
  IF AST.Op(AST.Child(root, 1)) = AST.OpAdd THEN INC(ok) END;
  IF AST.Kind(AST.Child(AST.Child(root, 1), 1)) = AST.NkIntLit THEN
    INC(ok)
  END;

  AST.Txt(AST.Child(AST.Child(root, 0), 0), s);
  IF s[0] = "a" THEN INC(ok) END;
  IF AST.AddTxt("b") = AST.AddTxt("b") THEN INC(ok) END;

  e1 := AST.MakeUn(AST.NkUnary, AST.OpSub,
           AST.MakeLeaf(AST.NkIntLit, "1"));
  root := AST.MakeNode(AST.NkBlock);
  IF AST.AddChild(root, e1) THEN INC(ok) END;
  IF AST.AddChild(root, e2) THEN INC(ok) END;
  IF AST.NChild(root) = 2 THEN INC(ok) END;

  FileIO.WriteString(FileIO.StdOut, "ok=");
  FileIO.WriteInt(FileIO.StdOut, ok, 1);
  FileIO.WriteLn(FileIO.StdOut);

  IF ok = 11 THEN ExitCode := 42 ELSE ExitCode := ok END
END TAst.