From f600634a8d29b6b6d45ebeac532839495c6531fc Mon Sep 17 00:00:00 2001
From: "Sven M. Hallberg" <pesco@khjk.org>
Date: Fri, 16 Sep 2022 11:55:24 +0200
Subject: [PATCH] refactor perform_lowlevel_parse for readability
Drive-by elimination of an age-old TODO. :)
Code should be functionally equivalent. Changes:
- Remove broken code under CONSISTENCY_CHECK.
- Transform to chip-away style.
- Remove braces around single statements.
- Declare variables at top of function.
- Shorten some variable names (tmp_res and bit_length).
- Limit line length to 80 columns.
---
src/backends/packrat.c | 61 +++++++++++++++++++++---------------------
1 file changed, 31 insertions(+), 30 deletions(-)
diff --git a/src/backends/packrat.c b/src/backends/packrat.c
index f95ba3de..dfda4367 100644
--- a/src/backends/packrat.c
+++ b/src/backends/packrat.c
@@ -34,37 +34,38 @@ HParserCacheValue *cached_lr(HParseState *state, HLeftRec *lr) {
return ret;
}
-// Really library-internal tool to perform an uncached parse, and handle any common error-handling.
-static inline HParseResult* perform_lowlevel_parse(HParseState *state, const HParser *parser) {
- // TODO(thequux): these nested conditions are ugly. Factor this appropriately, so that it is clear which codes is executed when.
- HParseResult *tmp_res;
- if (parser) {
- HInputStream bak = state->input_stream;
- tmp_res = parser->vtable->parse(parser->env, state);
- if (tmp_res) {
- tmp_res->arena = state->arena;
- if (!state->input_stream.overrun) {
- size_t bit_length = h_input_stream_pos(&state->input_stream) - h_input_stream_pos(&bak);
- if (tmp_res->bit_length == 0) { // Don't modify if forwarding.
- tmp_res->bit_length = bit_length;
- }
- if (tmp_res->ast && tmp_res->ast->bit_length != 0) {
- ((HParsedToken*)(tmp_res->ast))->bit_length = bit_length;
- }
- } else
- tmp_res->bit_length = 0;
- }
- } else
- tmp_res = NULL;
- if (state->input_stream.overrun)
- return NULL; // overrun is always failure.
-#ifdef CONSISTENCY_CHECK
- if (!tmp_res) {
- state->input_stream = INVALID;
- state->input_stream.input = key->input_pos.input;
+// internal helper to perform an uncached parse and common error-handling
+static inline
+HParseResult *perform_lowlevel_parse(HParseState *state, const HParser *parser)
+{
+ HParseResult *res;
+ HInputStream bak;
+ size_t len;
+
+ if (!parser)
+ return NULL;
+
+ bak = state->input_stream;
+ res = parser->vtable->parse(parser->env, state);
+
+ if (!res)
+ return NULL;
+
+ // overrun is always failure.
+ if (state->input_stream.overrun) {
+ res->bit_length = 0;
+ return NULL;
}
-#endif
- return tmp_res;
+
+ // update result
+ res->arena = state->arena;
+ len = h_input_stream_pos(&state->input_stream) - h_input_stream_pos(&bak);
+ if (res->bit_length == 0) // Don't modify if forwarding.
+ res->bit_length = len;
+ if (res->ast && res->ast->bit_length != 0)
+ ((HParsedToken *)(res->ast))->bit_length = len;
+
+ return res;
}
HParserCacheValue* recall(HParserCacheKey *k, HParseState *state, HHashValue keyhash) {
--
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