parsergen: allow $$OUT as well as $$NEWLINE

[ocean] / csrc / parsergen.mdc

diff --git a/csrc/parsergen.mdc b/csrc/parsergen.mdc
index 1981c901ac013afe1a2ab932dbc2d8742666b964..76fec3a70a779cefe4589a9d79e861a61acd726e 100644 (file)
--- a/csrc/parsergen.mdc
+++ b/csrc/parsergen.mdc
@@ -499,6 +499,8 @@ Now we have all the bits we need to parse a full production.
                        vs = sym_find(g, tk.txt);
                        if (vs->num == TK_newline)
                                p.line_like = 1;
+                       else if (vs->num == TK_out)
+                               p.line_like = 2;
                        else if (vs->precedence == 0) {
                                err = "symbol after $$ must have precedence";
                                goto abort;
@@ -1348,7 +1350,8 @@ into the go to set, so the item is ineffective.
                        }
                        sn = save_set(g, LA);
                        LA = set_find(g, sn);
-                       symset_add(&LAnl, TK_newline, 0);
+                       if (symset_find(&LA, TK_newline))
+                               symset_add(&LAnl, TK_newline, 0);
                        snnl = save_set(g, LAnl);
                        LAnl = set_find(g, snnl);
                }
@@ -1650,8 +1653,10 @@ it up a bit.  First the items, with production number and associativity.
                        printf(" [%d%s]", s->precedence,
                               assoc_names[s->assoc]);
                }
-               if (pr->line_like)
+               if (pr->line_like == 1)
                        printf(" $$NEWLINE");
+               else if (pr->line_like)
+                       printf(" $$OUT");
                printf("\n");
        }
 
@@ -1790,14 +1795,10 @@ terminals to items where that terminal could be shifted and another
 which maps terminals to items that could be reduced when the terminal
 is in look-ahead.  We report when we get conflicts between the two.
 
-As a special case, if we find a SHIFT/REDUCE conflict, where a
-terminal that could be shifted is in the lookahead set of some
-reducable item, then set check if the reducable item also have
-`TK_newline` in its lookahead set.  If it does, then a newline will
-force the reduction, but anything else can reasonably be shifted, so
-that isn't really a conflict.  Such apparent conflicts do not get
-counted, and are reported as non-critical.  This will not affect a
-"traditional" grammar that does not include newlines as token.
+As a special case, if we find a SHIFT/REDUCE conflict, on the NEWLINE
+terminal, we ignore it.  NEWLINES are handled specially with its own
+rules for when to shift and when to reduce.  Conflicts are expected,
+but handled internally.
 
        static int conflicts_slr(struct grammar *g, enum grammar_type type)
        {
@@ -1851,12 +1852,9 @@ counted, and are reported as non-critical.  This will not affect a
                                for (k = 0; k < la.cnt; k++) {
                                        int pos = symset_find(&shifts, la.syms[k]);
                                        if (pos >= 0 && la.syms[k] != TK_newline) {
-                                               if (symset_find(&la, TK_newline) < 0) {
-                                                       printf("  State %d has SHIFT/REDUCE conflict on ", i);
-                                                       cnt++;
-                                               } else
-                                                       printf("  State %d has non-critical SHIFT/REDUCE conflict on ", i);
-                                               prtxt(g->symtab[la.syms[k]]->name);
+                                               printf("  State %d has SHIFT/REDUCE conflict on ", i);
+                                               cnt++;
+                                                       prtxt(g->symtab[la.syms[k]]->name);
                                                printf(":\n");
                                                report_item(g, shifts.data[pos]);
                                                report_item(g, itm);