tools/Coco/Parser.FRM

   1 (* parser module generated by Coco-R *)
   2 MODULE -->modulename;
   3
   4 IMPORT -->scanner;
   5
   6 CONST
   7         -->constants
   8         setSize = 32;  nSets = (maxT DIV setSize) + 1;
   9
  10 TYPE
  11         SymbolSet = ARRAY nSets OF SET;
  12
  13 VAR
  14         sym:     INTEGER;   (* current input symbol *)
  15         symSet:  ARRAY nrSets OF SymbolSet;
  16
  17 -->declarations
  18
  19 PROCEDURE Error (n: INTEGER);
  20 BEGIN -->errors
  21 END Error;
  22
  23 PROCEDURE Get;
  24 BEGIN
  25         -->scanProc
  26 END Get;
  27
  28 PROCEDURE Expect(n: INTEGER);
  29 BEGIN IF sym = n THEN Get ELSE Error(n) END
  30 END Expect;
  31
  32 PROCEDURE StartOf(s: INTEGER): BOOLEAN;
  33 BEGIN RETURN (sym MOD setSize) IN symSet[s, sym DIV setSize]
  34 END StartOf;
  35
  36 PROCEDURE ExpectWeak(n, follow: INTEGER);
  37 BEGIN
  38         IF sym = n THEN Get
  39         ELSE Error(n); WHILE ~ StartOf(follow) DO Get END
  40         END
  41 END ExpectWeak;
  42
  43 PROCEDURE WeakSeparator(n, syFol, repFol: INTEGER): BOOLEAN;
  44         VAR s: SymbolSet; i: INTEGER;
  45 BEGIN
  46         IF sym = n THEN Get; RETURN TRUE
  47         ELSIF StartOf(repFol) THEN RETURN FALSE
  48         ELSE
  49                 i := 0; WHILE i < nSets DO s[i] := symSet[syFol, i] + symSet[repFol, i] + symSet[0, i]; INC(i) END;
  50                 Error(n); WHILE ~ ((sym MOD setSize) IN s[sym DIV setSize]) DO Get END;
  51                 RETURN StartOf(syFol)
  52         END
  53 END WeakSeparator;
  54
  55 -->productions
  56
  57 PROCEDURE Parse*;
  58 BEGIN
  59         Get;
  60 -->parseRoot
  61 END Parse;
  62
  63 BEGIN
  64 -->initialization
  65 END -->modulename.