New file: skeleton for GLR (Generalized LR) parser.

[bison.git] / src / state.c

diff --git a/src/state.c b/src/state.c
index b8c647e823f8f16d915cf31d4d88dc2e299c4aac..cb4cd5bcc6bdab8a1023f7d8cc89a70b41c53dc2 100644 (file)
--- a/src/state.c
+++ b/src/state.c
@@ -1,5 +1,5 @@
 /* Type definitions for nondeterministic finite state machine for bison,
-   Copyright 2001 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002  Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -20,6 +20,7 @@
 
 
 #include "system.h"
+#include "gram.h"
 #include "state.h"
 
 /*---------------------------------.
@@ -80,3 +81,36 @@ reductions_new (int n)
   res->nreds = n;
   return res;
 }
+
+
+/*--------------------------------------------------------------.
+| Print on OUT all the lookaheads such that this STATE wants to |
+| reduce this RULE.                                             |
+`--------------------------------------------------------------*/
+
+void
+state_rule_lookaheads_print (state_t *state, rule_t *rule, FILE *out)
+{
+  int j, k;
+  int nlookaheads = 0;
+  /* Count the number of lookaheads corresponding to this rule.  */
+  for (j = 0; j < state->nlookaheads; ++j)
+    for (k = 0; k < ntokens; ++k)
+      if (bitset_test (state->lookaheads[j], k)
+         && state->lookaheads_rule[j]->number == rule->number)
+       nlookaheads++;
+
+  /* Print them if there are.  */
+  if (nlookaheads)
+    {
+      fprintf (out, "  [");
+      for (j = 0; j < state->nlookaheads; ++j)
+       for (k = 0; k < ntokens; ++k)
+         if (bitset_test (state->lookaheads[j], k)
+             && state->lookaheads_rule[j]->number == rule->number)
+           fprintf (out, "%s%s",
+                    symbol_tag_get (symbols[k]),
+                    --nlookaheads ? ", " : "");
+      fprintf (out, "]");
+    }
+}