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use lookahead stream directly for LR (terminal) lookup

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This commit is contained in:
Sven M. Hallberg 2013-06-21 23:22:07 +02:00
parent 853e1fba46
commit 9585a5946e
4 changed files with 32 additions and 46 deletions
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25
src/backends/lr.c
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@ -216,7 +216,7 @@ HLREngine *h_lrengine_new(HArena *arena, HArena *tarena, const HLRTable *table,
}
static const HLRAction *
terminal_lookup(const HLREngine *engine, const HCFChoice *symbol)
terminal_lookup(const HLREngine *engine, const HInputStream *stream)
{
const HLRTable *table = engine->table;
size_t state = engine->state;
@ -226,11 +226,7 @@ terminal_lookup(const HLREngine *engine, const HCFChoice *symbol)
assert(h_lrtable_row_empty(table, state)); // that would be a conflict
return table->forall[state];
} else {
// XXX use the lookahead stream directly here (cf. llk)
if(symbol->type == HCF_END)
return table->tmap[state]->end_branch;
else
return h_stringmap_get(table->tmap[state], &symbol->chr, 1, false);
return h_stringmap_get_lookahead(table->tmap[state], *stream);
}
}
@ -248,22 +244,7 @@ nonterminal_lookup(const HLREngine *engine, const HCFChoice *symbol)
const HLRAction *h_lrengine_action(const HLREngine *engine)
{
HArena *tarena = engine->tarena;
// XXX use statically-allocated terminal symbols
HCFChoice *x = h_arena_malloc(tarena, sizeof(HCFChoice));
HInputStream lookahead = engine->input;
uint8_t c = h_read_bits(&lookahead, 8, false);
if(lookahead.overrun) { // end of input
x->type = HCF_END;
} else {
x->type = HCF_CHAR;
x->chr = c;
}
return terminal_lookup(engine, x);
return terminal_lookup(engine, &engine->input);
}
static HParsedToken *consume_input(HLREngine *engine)