add ERROR directive

[cpc.git] / src / generic / Dev / Mod / CPR.cp

diff --git a/src/generic/Dev/Mod/CPR.cp b/src/generic/Dev/Mod/CPR.cp
index 233b12166f49d168784e965a08de086fcda5069f..851d82e8b6000813164542de76d1b619d3e42194 100644 (file)
--- a/src/generic/Dev/Mod/CPR.cp
+++ b/src/generic/Dev/Mod/CPR.cp
@@ -7,10 +7,13 @@ MODULE DevCPR;
 
     (* symbol values *)
     null = 0;
-    if = 1; then = 2; else = 3; elsif = 4; end = 5; new = 6;
-    ident = 7; plus = 8; minus = 9;
-    not = 10; and = 11; or = 12; rpar = 13; lpar = 14;
-    endcom = 15; eof = 16;
+    if = 1; then = 2; else = 3; elsif = 4; end = 5;
+    new = 6; error = 7; ident = 8; plus = 9; minus = 10;
+    not = 11; and = 12; or = 13; rpar = 14; lpar = 15;
+    endcom = 16; eof = 17;
+
+    (* func numbers *)
+    var = 0; defined = 1;
 
   TYPE
     Context = POINTER TO RECORD
@@ -23,7 +26,8 @@ MODULE DevCPR;
     Selector = POINTER TO RECORD
       next: Selector;
       name: DevCPT.Name;
-      val: BOOLEAN
+      val: BOOLEAN;
+      num: BYTE
     END;
 
   VAR
@@ -70,6 +74,7 @@ MODULE DevCPR;
         IF name = "END" THEN sym := end
         ELSIF name = "ELSE" THEN sym := else
         ELSIF name = "ELSIF" THEN sym := elsif
+        ELSIF name = "ERROR" THEN sym := error
         END
     | "I": Identifier(sym); IF name = "IF" THEN sym := if END
     | "N": Identifier(sym); IF name = "NEW" THEN sym := new END
@@ -82,14 +87,16 @@ MODULE DevCPR;
     END
   END Get;
 
-  PROCEDURE New (IN name: DevCPT.Name; val: BOOLEAN);
+  PROCEDURE New (IN name: DevCPT.Name; val: BOOLEAN): Selector;
     VAR s: Selector;
   BEGIN
     s := scope;
     WHILE (s.next # NIL) & (s.next.name$ # name$) DO s := s.next END;
-    IF s.next = NIL THEN NEW(s.next); s.next.name := name$; s.next.val := val
+    IF s.next = NIL THEN
+      NEW(s.next); s.next.name := name$; s.next.num := var; s.next.val := val
     ELSE err(1)
-    END
+    END;
+    RETURN s.next
   END New;
 
   PROCEDURE Old (IN name: DevCPT.Name): Selector;
@@ -98,7 +105,7 @@ MODULE DevCPR;
     s := scope;
     WHILE (s.next # NIL) & (s.next.name$ # name$) DO s := s.next END;
     IF s.next = NIL THEN
-      err(0); NEW(s.next); s.next.name := name$; s.next.val := FALSE
+      err(0); NEW(s.next); s.next.name := name$; s.next.num := var; s.next.val := FALSE
     END;
     RETURN s.next
   END Old;
@@ -116,15 +123,32 @@ MODULE DevCPR;
   BEGIN
     s := scope;
     WHILE (s.next # NIL) & (s.next.name$ # name$) DO s := s.next END;
-    IF s.next = NIL THEN NEW(s.next); s.next.name := name$; s.next.val := val END
+    IF s.next = NIL THEN NEW(s.next) END;
+    s.next.name := name$; s.next.num := var; s.next.val := val
   END Set;
 
   PROCEDURE ^ Expression (VAR x: BOOLEAN);
 
   PROCEDURE Factor (VAR x: BOOLEAN);
+    VAR s: Selector;
   BEGIN x := FALSE;
     IF sym = ident THEN
-      x := Old(name).val; Get(sym)
+      s := Old(name); Get(sym);
+      IF s.num = var THEN
+         x := s.val
+      ELSIF sym = lpar THEN
+        Get(sym);
+        ASSERT(s.num = defined);
+        IF sym = ident THEN
+          x := Find(name) # NIL; Get(sym)
+        ELSE err(48)
+        END;
+        IF sym # rpar THEN err(23)
+        ELSE Get(sym)
+        END
+      ELSE
+        err(40)
+      END
     ELSIF sym = lpar THEN
       Get(sym); Expression(x);
       IF sym # rpar THEN err(23)
@@ -177,15 +201,25 @@ MODULE DevCPR;
     IF top = NIL THEN err(51); fold := 0; If(TRUE) END
   END End;
 
+  PROCEDURE Printable* (): BOOLEAN;
+    VAR c: Context;
+  BEGIN
+    c := top;
+    WHILE (c # NIL) & c.val DO c := c.next END;
+    RETURN c = NIL
+  END Printable;
+
   PROCEDURE Parse*;
-    VAR val: BOOLEAN;
+    VAR val: BOOLEAN; s: Selector;
   BEGIN
     Get(sym);
     IF sym = new THEN
       Get(sym);
-      IF sym = ident THEN New(name, FALSE); Get(sym)
+      IF sym = ident THEN s := New(name, FALSE); Get(sym)
       ELSE err(48)
       END
+    ELSIF sym = error THEN
+      IF Printable() THEN err(501) END; Get(sym)
     ELSIF sym = ident THEN
       Get(sym);
       IF sym = plus THEN Old(name).val := TRUE; Get(sym)
@@ -215,14 +249,6 @@ MODULE DevCPR;
     IF sym # endcom THEN err(5) ELSE DevCPM.errpos := DevCPM.curpos - 1 END
   END Parse;
 
-  PROCEDURE Printable* (): BOOLEAN;
-    VAR c: Context;
-  BEGIN
-    c := top;
-    WHILE (c # NIL) & c.val DO c := c.next END;
-    RETURN c = NIL
-  END Printable;
-
   PROCEDURE Check*;
   BEGIN
     IF fold # 1 THEN err(14) END
@@ -235,12 +261,14 @@ MODULE DevCPR;
   END Close;
 
   PROCEDURE Init*;
+    VAR s: Selector;
   BEGIN
     Close;
     If(TRUE);
     NEW(scope);
-    New("TRUE", TRUE);
-    New("FALSE", FALSE)
+    s := New("TRUE", TRUE);
+    s := New("FALSE", FALSE);
+    s := New("DEFINED", FALSE); s.num := defined
   END Init;
 
 END DevCPR.