M2compiler-V1/M2c.atg

COMPILER M2c
(* Phase 0: module skeleton only.
   Accepts "MODULE <name> ; [ BEGIN ] END <name> ." and checks that
   the closing name matches (error 202). No declarations, no
   statements, no symbol table yet — those arrive in Phase 1. *)

CHARACTERS
  letter = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" .
  digit  = "0123456789" .

IGNORE CHR(9) .. CHR(13)

COMMENTS
  FROM "(*" TO "*)" NESTED

TOKENS
  ident = letter { letter | digit } .

PRODUCTIONS
  M2c                             (. VAR m1, m2: ARRAY [0 .. 63] OF CHAR;
                                       i: CARDINAL; same: BOOLEAN; .)
    = "MODULE" ident              (. LexName(m1); .)
      ";" [ "BEGIN" ] "END"
      ident                       (. LexName(m2);
                                     i := 0; same := TRUE;
                                     WHILE same & ((m1[i] # 0C)
                                           OR (m2[i] # 0C)) DO
                                       IF m1[i] # m2[i] THEN
                                         same := FALSE
                                       END;
                                       INC(i)
                                     END;
                                     IF ~same THEN SemError(202) END; .)
      "." .

END M2c.