Optimize parsers: O(n²) → O(n) offset calculation#121
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RegexParser and WordpressParser recomputed each match's character offset with mb_strlen(substr($text, 0, $match[1])), rescanning the whole prefix for every match, which is O(n^2) in the number of shortcodes. Accumulate the character offset incrementally instead, measuring only the new segment since the previous match. Matches come back in ascending offset order, so the running total stays exact. On a 504 KB document with 1,500 shortcodes: RegexParser 223.5 ms -> 3.4 ms (66x) WordpressParser 221.7 ms -> 1.0 ms (222x) Also: - replace the hand-rolled per-character backslash escaping with preg_quote() in RegularParser and RegexBuilderUtility, - drop a no-op array_filter() in RegexParser::parse() (parseSingle() never returns null), - iterate replacements with a reverse for-loop instead of allocating an array_reverse() copy in Processor, - short-circuit the Shortcode parameter-type check on the first invalid value instead of array_filter over all of them. No behavior change: the full test suite passes (288 tests, 2256 assertions).
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Summary
RegexParserandWordpressParsercomputed each match's character offset withmb_strlen(substr($text, 0, $match[1])), which rescans the entire prefix for every match. That makes parsing O(n²) in the number of shortcodes, and on large documents it dominates the parse time.This PR accumulates the character offset incrementally, measuring only the new segment of text since the previous match.
preg_match_all(and the WordPress loop) return matches in ascending offset order, so the running total stays exact. The result is O(n).Benchmark
504 KB document, 1,500 shortcodes:
RegexParserWordpressParserRegularParseris unaffected by the offset change (it tokenizes differently).Also included (small, behavior-preserving)
preg_replace('/(.)/us', '\\$0', ...)) withpreg_quote()inRegularParserandRegexBuilderUtility.array_filter()inRegexParser::parse();parseSingle()always returns aParsedShortcode, nevernull.forloop instead of allocating anarray_reverse()copy inProcessor.Shortcodeparameter-type validation on the first invalid value instead ofarray_filterover all of them, and cache a fewSyntaxaccessors inRegexParser.Tests
No behavior change. The full suite passes: 288 tests, 2256 assertions.