| commit | 4933cef850c0c8a22eee3194ddf1c08b76c31828 | [log] [tgz] |
|---|---|---|
| author | Nate Bosch <nbosch1@gmail.com> | Tue Nov 03 14:35:30 2020 -0800 |
| committer | GitHub <noreply@github.com> | Tue Nov 03 14:35:30 2020 -0800 |
| tree | 8eec0039846341ae1983f01b2b6153a6d474309b | |
| parent | d01cd8000f28571db79e5b7c6c98767fcedd9286 [diff] |
Bump SDK constraints for pub (#28) Use a 2.12.0 lower bound since pub does not understand allowed experiments for earlier versions. Use a 3.0.0 upper bound to avoid a warning in pub and to give some flexibility in publishing for stable.
This package exposes a StringScanner type that makes it easy to parse a string using a series of Patterns. For example:
import 'dart:math' as math; import 'package:string_scanner/string_scanner.dart'; num parseNumber(String source) { // Scan a number ("1", "1.5", "-3"). final scanner = StringScanner(source); // [Scanner.scan] tries to consume a [Pattern] and returns whether or not it // succeeded. It will move the scan pointer past the end of the pattern. final negative = scanner.scan('-'); // [Scanner.expect] consumes a [Pattern] and throws a [FormatError] if it // fails. Like [Scanner.scan], it will move the scan pointer forward. scanner.expect(RegExp(r'\d+')); // [Scanner.lastMatch] holds the [MatchData] for the most recent call to // [Scanner.scan], [Scanner.expect], or [Scanner.matches]. var number = num.parse(scanner.lastMatch[0]); if (scanner.scan('.')) { scanner.expect(RegExp(r'\d+')); final decimal = scanner.lastMatch[0]; number += int.parse(decimal) / math.pow(10, decimal.length); } // [Scanner.expectDone] will throw a [FormatError] if there's any input that // hasn't yet been consumed. scanner.expectDone(); return (negative ? -1 : 1) * number; }