Lemon update 2014-01-11 03:06:18 on branch lemon-updates

- Add the new "%token_class" directive for defining symbolic names that stand any one of a collection of tokens. (user: drh)

tools/lemon/lemon.c

@@ -1463,12 +1463,15 @@ int main(int argc, char **argv)
   }
 
   /* Count and index the symbols of the grammar */
-  lem.nsymbol = Symbol_count();
   Symbol_new("{default}");
+  lem.nsymbol = Symbol_count();
   lem.symbols = Symbol_arrayof();
-  for(i=0; i<=lem.nsymbol; i++) lem.symbols[i]->index = i;
+  for(i=0; i<lem.nsymbol; i++) lem.symbols[i]->index = i;
-  qsort(lem.symbols,lem.nsymbol+1,sizeof(struct symbol*), Symbolcmpp);
+  qsort(lem.symbols,lem.nsymbol,sizeof(struct symbol*), Symbolcmpp);
-  for(i=0; i<=lem.nsymbol; i++) lem.symbols[i]->index = i;
+  for(i=0; i<lem.nsymbol; i++) lem.symbols[i]->index = i;
+  while( lem.symbols[i-1]->type==MULTITERMINAL ){ i--; }
+  assert( strcmp(lem.symbols[i-1]->name,"{default}")==0 );
+  lem.nsymbol = i - 1;
   for(i=1; isupper(lem.symbols[i]->name[0]); i++);
   lem.nterminal = i;
 
@@ -1947,7 +1950,9 @@ enum e_state {
   WAITING_FOR_DESTRUCTOR_SYMBOL,
   WAITING_FOR_DATATYPE_SYMBOL,
   WAITING_FOR_FALLBACK_ID,
-  WAITING_FOR_WILDCARD_ID
+  WAITING_FOR_WILDCARD_ID,
+  WAITING_FOR_CLASS_ID,
+  WAITING_FOR_CLASS_TOKEN
 };
 struct pstate {
   char *filename;       /* Name of the input file */
@@ -1957,6 +1962,7 @@ struct pstate {
   struct lemon *gp;     /* Global state vector */
   enum e_state state;        /* The state of the parser */
   struct symbol *fallback;   /* The fallback token */
+  struct symbol *tkclass;    /* Token class symbol */
   struct symbol *lhs;        /* Left-hand side of current rule */
   const char *lhsalias;      /* Alias for the LHS */
   int nrhs;                  /* Number of right-hand side symbols seen */
@@ -2260,6 +2266,8 @@ to follow the previous rule.");
           psp->state = WAITING_FOR_FALLBACK_ID;
         }else if( strcmp(x,"wildcard")==0 ){
           psp->state = WAITING_FOR_WILDCARD_ID;
+        }else if( strcmp(x,"token_class")==0 ){
+          psp->state = WAITING_FOR_CLASS_ID;
         }else{
           ErrorMsg(psp->filename,psp->tokenlineno,
             "Unknown declaration keyword: \"%%%s\".",x);
@@ -2428,6 +2436,40 @@ to follow the previous rule.");
         }
       }
       break;
+    case WAITING_FOR_CLASS_ID:
+      if( !islower(x[0]) ){
+        ErrorMsg(psp->filename, psp->tokenlineno,
+          "%%token_class must be followed by an identifier: ", x);
+        psp->errorcnt++;
+        psp->state = RESYNC_AFTER_DECL_ERROR;
+     }else if( Symbol_find(x) ){
+        ErrorMsg(psp->filename, psp->tokenlineno,
+          "Symbol \"%s\" already used", x);
+        psp->errorcnt++;
+        psp->state = RESYNC_AFTER_DECL_ERROR;
+      }else{
+        psp->tkclass = Symbol_new(x);
+        psp->tkclass->type = MULTITERMINAL;
+        psp->state = WAITING_FOR_CLASS_TOKEN;
+      }
+      break;
+    case WAITING_FOR_CLASS_TOKEN:
+      if( x[0]=='.' ){
+        psp->state = WAITING_FOR_DECL_OR_RULE;
+      }else if( isupper(x[0]) || ((x[0]=='|' || x[0]=='/') && isupper(x[1])) ){
+        struct symbol *msp = psp->tkclass;
+        msp->nsubsym++;
+        msp->subsym = (struct symbol **) realloc(msp->subsym,
+          sizeof(struct symbol*)*msp->nsubsym);
+        if( !isupper(x[0]) ) x++;
+        msp->subsym[msp->nsubsym-1] = Symbol_new(x);
+      }else{
+        ErrorMsg(psp->filename, psp->tokenlineno,
+          "%%token_class argument \"%s\" should be a token", x);
+        psp->errorcnt++;
+        psp->state = RESYNC_AFTER_DECL_ERROR;
+      }
+      break;
     case RESYNC_AFTER_RULE_ERROR:
 /*      if( x[0]=='.' ) psp->state = WAITING_FOR_DECL_OR_RULE;
 **      break; */
@@ -2800,11 +2842,13 @@ void Reprint(struct lemon *lemp)
     printf(" ::=");
     for(i=0; i<rp->nrhs; i++){
       sp = rp->rhs[i];
-      printf(" %s", sp->name);
       if( sp->type==MULTITERMINAL ){
+        printf(" %s", sp->subsym[0]->name);
         for(j=1; j<sp->nsubsym; j++){
           printf("|%s", sp->subsym[j]->name);
         }
+      }else{
+        printf(" %s", sp->name);
       }
       /* if( rp->rhsalias[i] ) printf("(%s)",rp->rhsalias[i]); */
     }
@@ -2826,11 +2870,13 @@ void ConfigPrint(FILE *fp, struct config *cfp)
     if( i==cfp->dot ) fprintf(fp," *");
     if( i==rp->nrhs ) break;
     sp = rp->rhs[i];
-    fprintf(fp," %s", sp->name);
     if( sp->type==MULTITERMINAL ){
+      fprintf(fp," %s", sp->subsym[0]->name);
       for(j=1; j<sp->nsubsym; j++){
         fprintf(fp,"|%s",sp->subsym[j]->name);
       }
+    }else{
+      fprintf(fp," %s", sp->name);
     }
   }
 }
@@ -3587,9 +3633,11 @@ static void writeRuleText(FILE *out, struct rule *rp){
   fprintf(out,"%s ::=", rp->lhs->name);
   for(j=0; j<rp->nrhs; j++){
     struct symbol *sp = rp->rhs[j];
+    if( sp->type!=MULTITERMINAL ){
       fprintf(out," %s", sp->name);
-    if( sp->type==MULTITERMINAL ){
+    }else{
       int k;
+      fprintf(out," %s", sp->subsym[0]->name);
       for(k=1; k<sp->nsubsym; k++){
         fprintf(out,"|%s",sp->subsym[k]->name);
       }
@@ -4058,7 +4106,8 @@ void ReportHeader(struct lemon *lemp)
   if( in ){
     int nextChar;
     for(i=1; i<lemp->nterminal && fgets(line,LINESIZE,in); i++){
-      sprintf(pattern,"#define %s%-30s %2d\n",prefix,lemp->symbols[i]->name,i);
+      sprintf(pattern,"#define %s%-30s %2d\n",
+              prefix,lemp->symbols[i]->name,i);
       if( strcmp(line,pattern) ) break;
     }
     nextChar = fgetc(in);
@@ -4072,7 +4121,7 @@ void ReportHeader(struct lemon *lemp)
   out = file_open(lemp,".h","wb");
   if( out ){
     for(i=1; i<lemp->nterminal; i++){
-      fprintf(out,"#define %s%-30s %2d\n",prefix,lemp->symbols[i]->name,i);
+      fprintf(out,"#define %s%-30s %3d\n",prefix,lemp->symbols[i]->name,i);
     }
     fclose(out);  
   }
@@ -4442,11 +4491,15 @@ struct symbol *Symbol_new(const char *x)
   return sp;
 }
 
-/* Compare two symbols for working purposes
+/* Compare two symbols for sorting purposes.  Return negative,
+** zero, or positive if a is less then, equal to, or greater
+** than b.
 **
 ** Symbols that begin with upper case letters (terminals or tokens)
 ** must sort before symbols that begin with lower case letters
-** (non-terminals).  Other than that, the order does not matter.
+** (non-terminals).  And MULTITERMINAL symbols (created using the
+** %token_class directive) must sort at the very end. Other than
+** that, the order does not matter.
 **
 ** We find experimentally that leaving the symbols in their original
 ** order (the order they appeared in the grammar file) gives the
@@ -4454,12 +4507,11 @@ struct symbol *Symbol_new(const char *x)
 */
 int Symbolcmpp(const void *_a, const void *_b)
 {
-  const struct symbol **a = (const struct symbol **) _a;
+  const struct symbol *a = *(const struct symbol **) _a;
-  const struct symbol **b = (const struct symbol **) _b;
+  const struct symbol *b = *(const struct symbol **) _b;
-  int i1 = (**a).index + 10000000*((**a).name[0]>'Z');
+  int i1 = a->type==MULTITERMINAL ? 3 : a->name[0]>'Z' ? 2 : 1;
-  int i2 = (**b).index + 10000000*((**b).name[0]>'Z');
+  int i2 = b->type==MULTITERMINAL ? 3 : b->name[0]>'Z' ? 2 : 1;
-  assert( i1!=i2 || strcmp((**a).name,(**b).name)==0 );
+  return i1==i2 ? a->index - b->index : i1 - i2;
-  return i1-i2;
 }
 
 /* There is one instance of the following structure for each