Add the EXACT literal regex engine (--regextype=EXACT), unify -grep's literal path (#85) - #314
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… literal path (#85) EXACT becomes a first-class match engine (Grammar::kExact) behind the RegexBackend seam, not a -grep-only bool - the first non-RE2 engine, proving the multi-engine architecture with a trivial core (always-linked, no dependency) backend. - regex: ExactBackend implements RegexBackend via std::string comparison - FullMatch = equality, PartialMatch = substring, FindFirst = first occurrence span, Rewrite = literal find/replace (no backreferences); case_insensitive folds ASCII case on both sides. Compile(kExact) never fails (no pattern to compile). - parser: GrammarFromGlobals maps --regextype=EXACT -> kExact, so EXACT now reaches every pattern predicate (-regex/-rxc/-grep), not just -grep. - engine: unify -grep. The old ctx.grep_literal StrContains path is exactly what ExactBackend.PartialMatch/FindFirst do, so -grep now runs through the pre-compiled matcher like -rxc; drop the grep_literal EvalContext field. Behavior is preserved (the existing EXACT -grep test still passes) and EXACT now respects case mode uniformly (the old StrContains path ignored -i/smart-case). - run: ResolveGrepLiteral (returned the literal bool) becomes ValidateRegextype (validates the selector only; PCRE2-not-built / MATCH-reserved / unknown are still usage errors before the walk). The grammar is resolved by the parser. - help: --regextype summary reframed as "match engine: RE2 / EXACT / PCRE2". Tests: regex_test (kExact ops + ci + literal span), parser_test (EXACT -> kExact), evaluate_test (-grep and -rxc under EXACT). bazel test //xff/... -> 72/72.
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EXACT becomes a first-class match engine (
Grammar::kExact) behind theRegexBackendseam, not a-grep-only bool. It's the first non-RE2 engine - a trivial, always-linked core backend that proves the multi-engine architecture ahead of the PCRE2 (build-extra) work.What this does
ExactBackendimplementsRegexBackendviastd::stringcomparison:FullMatch= equality,PartialMatch= substring,FindFirst= first-occurrence span,Rewrite= literal find/replace (no backreferences);case_insensitivefolds ASCII case on both sides.Compile(kExact)never fails (no pattern to compile).--regextype=EXACTnow reaches every pattern predicate (-regex/-rxc/-grep), not just-grep:GrammarFromGlobalsmapsEXACT -> kExact.-grepunified. The oldctx.grep_literalStrContainspath is exactly whatExactBackend.PartialMatch/FindFirstdo, so-grepnow runs through the pre-compiled matcher like-rxc; thegrep_literalEvalContextfield is gone. Behavior is preserved (the existing EXACT-greptest still passes), and EXACT now respects case-mode uniformly (the oldStrContainspath silently ignored-i/smart-case).ResolveGrepLiteral->ValidateRegextype(validates the selector only; PCRE2-not-built / MATCH-reserved / unknown remain usage errors before the walk). The grammar is resolved by the parser.--regextypesummary reframed as "match engine: RE2 / EXACT / PCRE2".Test
regex_test(kExact ops + case-insensitive + literal span),parser_test(EXACT -> kExact),evaluate_test(-grepand-rxcunder EXACT).bazel test //xff/...-> 72/72.Next (regextype engine family, #85 / #121)
FNMATCH (flat wildcard via
::fnmatch) and GLOB (path-aware, via theignore.ccglob->RE2 translator) core engines, then PCRE2 (the build extra:third_party/pcre2+ notice + full CI cell).