| Summary: | Expressions using {0,n} match 0 to n+1 times instead of 0 to n times | ||
|---|---|---|---|
| Product: | Regexp | Reporter: | Chris Scheuble <chriss> |
| Component: | Other | Assignee: | Jakarta Notifications Mailing List <notifications> |
| Status: | CLOSED DUPLICATE | ||
| Severity: | normal | ||
| Priority: | P3 | ||
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Hardware: | PC | ||
| OS: | All | ||
patches applied and tested closed I belive this is not correct solution; testcase #174 output must be '', and Perl
agrees with me:
#!/usr/bin/perl
print "Matching '123abcdefg123' with regexp '([a-z]{0,3})':\n";
if ("123abcdefg123" =~ /([a-z]{0,3})/) {
print "Matches. Result: '$1'\n";
}
Output:
Matching '123abcdefg123' with regexp '([a-z]{0,3})':
Matches. Result: ''
Patch will follow...
*** This bug has been marked as a duplicate of 19329 *** Fixed by Bug #19329 |
Expressions using {0,n} match 0 to n+1 times instead of 0 to n times. Expression "[a-z]{0,3}" against "123abcdefg123" matches "abcd" not "abc". I fixed the problem in the compiler by changing the method void bracket()... /** * Match bracket {m,n} expression put results in bracket member variables * @exception RESyntaxException Thrown if the regular expression has invalid syntax. */ void bracket() throws RESyntaxException { // Current character must be a '{' if (idx >= len || pattern.charAt(idx++) != '{') { internalError(); } // Next char must be a digit if (idx >= len || !Character.isDigit(pattern.charAt(idx))) { syntaxError("Expected digit"); } // Get min ('m' of {m,n}) number StringBuffer number = new StringBuffer(); while (idx < len && Character.isDigit(pattern.charAt(idx))) { number.append(pattern.charAt(idx++)); } try { bracketMin[brackets] = Integer.parseInt(number.toString()); } catch (NumberFormatException e) { syntaxError("Expected valid number"); } // If out of input, fail if (idx >= len) { syntaxError("Expected comma or right bracket"); } // If end of expr, optional limit is 0 if (pattern.charAt(idx) == '}') { if (bracketMin[brackets] < 1) { syntaxError("Bad zero range"); } idx++; bracketOpt[brackets] = 0; return; } // Must have at least {m,} and maybe {m,n}. if (idx >= len || pattern.charAt(idx++) != ',') { syntaxError("Expected comma"); } // If out of input, fail if (idx >= len) { syntaxError("Expected comma or right bracket"); } // If {m,} max is unlimited if (pattern.charAt(idx) == '}') { idx++; bracketOpt[brackets] = bracketUnbounded; return; } // Next char must be a digit if (idx >= len || !Character.isDigit(pattern.charAt(idx))) { syntaxError("Expected digit"); } // Get max number number.setLength(0); while (idx < len && Character.isDigit(pattern.charAt(idx))) { number.append(pattern.charAt(idx++)); } try { bracketOpt[brackets] = Integer.parseInt(number.toString()) - bracketMin[brackets]; /**/ if (bracketMin[brackets] < 1) bracketOpt[brackets]--; /**/ } catch (NumberFormatException e) { syntaxError("Expected valid number"); } // Optional repetitions must be > 0 /* if (bracketOpt[brackets] <= 0) */ if (bracketOpt[brackets] < 0) { syntaxError("Bad range"); } // Must have close brace if (idx >= len || pattern.charAt(idx++) != '}') { syntaxError("Missing close brace"); } }