From 4c5ca5ceab9efbe76c470661982971b83e14b0fb Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Thu, 23 May 2013 22:54:49 +0200
Subject: [PATCH] clean up a bit
---
src/backends/llk.c | 28 +++++++++++++++-------------
1 file changed, 15 insertions(+), 13 deletions(-)
diff --git a/src/backends/llk.c b/src/backends/llk.c
index acd6c5f5..ad09aa5a 100644
--- a/src/backends/llk.c
+++ b/src/backends/llk.c
@@ -171,8 +171,7 @@ static void stringmap_merge(HHashSet *workset, HCFStringMap *dst, HCFStringMap *
static int fill_table_row(size_t kmax, HCFGrammar *g, HCFStringMap *row,
const HCFChoice *A)
{
- HHashSet *workset; // to be deleted after compile
- // ~> alloc in g->arena
+ HHashSet *workset;
// initialize working set to the productions of A
workset = h_hashset_new(g->arena, h_eq_ptr, h_hash_ptr);
@@ -182,7 +181,10 @@ static int fill_table_row(size_t kmax, HCFGrammar *g, HCFStringMap *row,
// run until workset exhausted or kmax hit
size_t k;
for(k=1; k<=kmax; k++) {
- // iterate over productions in workset...
+ // allocate a fresh workset for the next round
+ HHashSet *nextset = h_hashset_new(g->arena, h_eq_ptr, h_hash_ptr);
+
+ // iterate over the productions in workset...
const HHashTable *ht = workset;
for(size_t i=0; i < ht->capacity; i++) {
for(HHashTableEntry *hte = &ht->contents[i]; hte; hte = hte->next) {
@@ -193,18 +195,20 @@ static int fill_table_row(size_t kmax, HCFGrammar *g, HCFStringMap *row,
assert(rhs != NULL);
assert(rhs != CONFLICT); // just to be sure there's no mixup
- // remove this production from workset
- h_hashset_del(workset, rhs);
-
// calculate predict set; let values map to rhs
HCFStringMap *pred = h_predict(k, g, A, rhs);
h_stringmap_replace(pred, NULL, rhs);
- // merge predict set into the row; accumulates conflicts in workset
- stringmap_merge(workset, row, pred);
+ // merge predict set into the row
+ // accumulates conflicts in new workset
+ stringmap_merge(nextset, row, pred);
}
}
+ // switch to the updated workset
+ h_hashtable_free(workset);
+ workset = nextset;
+
// if the workset is empty, row is without conflict; we're done
if(h_hashset_empty(workset))
break;
@@ -213,10 +217,8 @@ static int fill_table_row(size_t kmax, HCFGrammar *g, HCFStringMap *row,
h_stringmap_replace(row, CONFLICT, NULL);
}
- if(k>kmax) // conflicts remain
- return -1;
- else
- return 0;
+ h_hashset_free(workset);
+ return (k>kmax)? -1 : 0;
}
/* Generate the LL(k) parse table from the given grammar.
@@ -483,7 +485,7 @@ int test_llk(void)
return 2;
}
- HParseResult *res = h_parse(p, (uint8_t *)"xya", 3);
+ HParseResult *res = h_parse(p, (uint8_t *)"xa", 2);
if(res)
h_pprint(stdout, res->ast, 0, 2);
else
--
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