diff --git a/lib/modules/LR.pmod/parser.pike b/lib/modules/LR.pmod/parser.pike
index 003b7deb8bbfccb177df71f25719e87127845cac..1faf7076cd9436b983f2e3aac3520e1c8646c2b1 100644
--- a/lib/modules/LR.pmod/parser.pike
+++ b/lib/modules/LR.pmod/parser.pike
@@ -1,5 +1,5 @@
/*
- * $Id: parser.pike,v 1.9 1998/11/14 01:20:02 grubba Exp $
+ * $Id: parser.pike,v 1.10 1998/11/14 04:22:06 grubba Exp $
*
* A BNF-grammar in Pike.
* Compiles to a LALR(1) state-machine.
@@ -9,7 +9,7 @@
//.
//. File: parser.pike
-//. RCSID: $Id: parser.pike,v 1.9 1998/11/14 01:20:02 grubba Exp $
+//. RCSID: $Id: parser.pike,v 1.10 1998/11/14 04:22:06 grubba Exp $
//. Author: Henrik Grubbstr�m (grubba@infovav.se)
//.
//. Synopsis: LALR(1) parser and compiler.
@@ -21,7 +21,6 @@
//. Normal use of this object would be:
//.
//. {add_rule, set_priority, set_associativity}*
-//. set_scanner
//. set_symbol_to_string
//. compile
//. {parse}*
@@ -72,6 +71,10 @@ class kernel {
//. Contains the items in this state.
array(object(item)) items = ({});
+ //. + item_id_to_items
+ //. Used to lookup items given rule and offset
+ mapping(int:object(item)) item_id_to_item = ([]);
+
//. + symbol_items
//. Contains the items whose next symbol is this non-terminal.
mapping(int : multiset(object(item))) symbol_items = ([]);
@@ -96,6 +99,8 @@ class kernel {
int|string symbol;
items += ({ i });
+ item_id_to_item[i->item_id] = i;
+
if (i->offset < sizeof(i->r->symbols)) {
symbol = i->r->symbols[i->offset];
@@ -768,16 +773,20 @@ static private int go_through(object(kernel) state, object(rule) r, int offset,
int index;
object(item) i, master;
+ i = state->item_id_to_item[r->number + offset];
+#if 0
for (index = 0; index < sizeof(state->items); index++) {
if ((state->items[index]->r == r) &&
(state->items[index]->offset == offset)) {
/* Found the index for the current rule and offset */
+ i = state->items[index];
break;
}
}
+#endif /* 0 */
/* What to do if not found? */
- if (index == sizeof(state->items)) {
+ if (!i) {
werror(sprintf("go_through: item with offset %d in rule\n%s\n"
"not found in state\n%s\n",
offset, rule_to_string(r), state_to_string(state)));
@@ -785,7 +794,6 @@ static private int go_through(object(kernel) state, object(rule) r, int offset,
return(0);
}
- i = state->items[index];
if (i->master_item) {
master = i->master_item;
} else {
@@ -1224,38 +1232,59 @@ int compile()
/* Compute lookback-sets */
for (int index = 0; index < s_q->tail; index++) {
array(object(item)) items = s_q->arr[index]->items;
+ // Set up a lookup table to speedup lookups later.
+ mapping(int:array(object(item))) lookup = ([]);
+ foreach (items, object(item) i) {
+ if (!i->offset) {
+ if (!lookup[i->r->nonterminal]) {
+ lookup[i->r->nonterminal] = ({ i });
+ } else {
+ lookup[i->r->nonterminal] += ({ i });
+ }
+ }
+ }
foreach (items, object(item) transition) {
int|string symbol;
- if ((transition->offset != sizeof(transition->r->symbols)) &&
- (intp(symbol = transition->r->symbols[transition->offset])) &&
- (!transition->master_item)) {
- /* NonTerminal and master item*/
+ if ((!transition->master_item) &&
+ (transition->offset != sizeof(transition->r->symbols)) &&
+ (intp(symbol = transition->r->symbols[transition->offset]))) {
+ /* Master item and
+ * Not a reduction item and
+ * next symbol is a NonTerminal
+ */
+ if (!lookup[symbol]) {
+ // Foo? Shouldn't these always exist since we've made
+ // a closure earlier?
+ werror(sprintf("WARNING: No item for symbol <%s>\n"
+ "in state:\n"
+ "%s\n",
+ symbol_to_string(symbol),
+ state_to_string(s_q->arr[index])));
+ continue;
+ }
/* Find items which can reduce to the nonterminal from above */
- foreach (items, object(item) i2) {
- if ((!i2->offset) &&
- (i2->r->nonterminal == symbol)) {
- if (sizeof(i2->r->symbols)) {
- if (go_through(i2->next_state, i2->r, i2->offset+1,
- transition)) {
- /* Nullable */
- object(item) master = i2;
- if (i2->master_item) {
- master = i2->master_item;
- }
- /* Is this a nonterminal transition? */
- if ((master->offset != sizeof(master->r->symbols)) &&
- (intp(master->r->symbols[master->offset]))) {
- /* Don't include ourselves */
- if (master != transition) {
- master->relation[transition] = 1;
- }
+ foreach (lookup[symbol], object(item) i) {
+ if (sizeof(i->r->symbols)) {
+ if (go_through(i->next_state, i->r, i->offset+1,
+ transition)) {
+ /* Nullable */
+ object(item) master = i;
+ if (i->master_item) {
+ master = i->master_item;
+ }
+ /* Is this a nonterminal transition? */
+ if ((master->offset != sizeof(master->r->symbols)) &&
+ (intp(master->r->symbols[master->offset]))) {
+ /* Don't include ourselves */
+ if (master != transition) {
+ master->relation[transition] = 1;
}
}
- } else {
- i2->relation[transition] = 1;
}
+ } else {
+ i->relation[transition] = 1;
}
}
}
@@ -1369,8 +1398,8 @@ int compile()
//. Parse the input according to the compiled grammar.
//. The last value reduced is returned.
//. NOTA BENE:
-//. The parser must have been compiled (with compile()), and a scanner
-//. been set (with set_scanner()) prior to calling this function.
+//. The parser must have been compiled (with compile())
+//. prior to calling this function.
//. BUGS
//. Errors should be throw()n.
//. > scanner
@@ -1381,7 +1410,7 @@ int compile()
//. > action_object
//. Object used to resolve those actions that have been specified as
//. strings.
-mixed parse(function(void:string|array(string|mixed)) scanner,
+mixed parse(object|function(void:string|array(string|mixed)) scanner,
void|object action_object)
{
object(Stack.stack) value_stack = Stack.stack();
@@ -1393,7 +1422,8 @@ mixed parse(function(void:string|array(string|mixed)) scanner,
error = 0; /* No parse error yet */
- if (!scanner || !functionp(scanner)) {
+ if (!functionp(scanner) &&
+ !(objectp(scanner) && functionp(scanner->`()))) {
werror("parser->parse(): scanner not set!\n");
error = ERROR_NO_SCANNER;
return(0);