commit | 42d1f447a3003d237497ea068b63751b55331ed4 | [log] [tgz] |
---|---|---|
author | Kevin Moore <kevmoo@google.com> | Mon Mar 09 12:28:23 2020 -0700 |
committer | Kevin Moore <kevmoo@users.noreply.github.com> | Mon Mar 09 13:05:04 2020 -0700 |
tree | 5898a8da7adc43ea11ab804e94dc9c011938a5df | |
parent | 1587bd7bc793c26c78865f16ebcc7f9454981823 [diff] |
Fix readme Align with example/example.dart
This package exposes a StringScanner
type that makes it easy to parse a string using a series of Pattern
s. 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; }