http://d.puremagic.com/issues/show_bug.cgi?id=5511
Summary: std.regex optional capture with no-match cause error Product: D Version: D2 Platform: All OS/Version: All Status: NEW Keywords: patch Severity: normal Priority: P2 Component: Phobos AssignedTo: nob...@puremagic.com ReportedBy: himana.kar...@orange.fr --- Comment #0 from karasu <himana.kar...@orange.fr> 2011-01-31 05:33:58 PST --- version used: 2.051 An matching optional capture works: auto ms = match("ab", "(a(.*))?(b)"); assert(ms.captures.length == 4); // Ok assert(ms.captures[0] == "ab"); // Ok assert(ms.captures[1] == "a"); // Ok assert(ms.captures[2] == ""); // Ok assert(ms.captures[3] == "b"); // Ok But if optional capture doesn't match : auto ms = match("b", "(a(.*))?(b)"); // same issue with pattern "(a(.*))*(b)" assert(ms.captures.length == 4); // Failed length = 1 assert(ms.captures[0] == "b"); // Ok assert(ms.captures[1] == ""); // core.exception.AssertError@regex.d(1724): 1 assert(ms.captures[2] == ""); // core.exception.AssertError@regex.d(1724): 1 assert(ms.captures[3] == "b"); // core.exception.AssertError@regex.d(1724): 1 In Captures.length (line 1713 in v2.051): @property size_t length() { foreach (i; 0 .. matches.length) { if (matches[i].startIdx >= input.length) return i; } return matches.length; } for matches[1] and matches[2], startIdx == endIdx == startIdx.max but matches[3] is fine: startIdx == 0 and endIdx == 1 in RegexMatch.trymatch (line 2397 in v2.051) startIdx and endIdx are set only if matching: case engine.REparen: // ... pass if (!trymatch(pop, pop + len)) goto Lnomatch; pmatch[n + 1].startIdx = ss; pmatch[n + 1].endIdx = src; pc = pop + len; break; and in RegexMatch.test (line 1905 in v2.051) startIdx and endIdx are initialized to max for each match: foreach (i; 0 .. engine.re_nsub + 1) { pmatch[i].startIdx = -1; pmatch[i].endIdx = -1; } in RegexMatch.test (line 1905 in v2.051) initializing startIdx and endIdx to startindex instead of max seems to fix the problem: foreach (i; 0 .. engine.re_nsub + 1) { pmatch[i].startIdx = startindex; pmatch[i].endIdx = startindex; } -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------