commit | ac159dedba7e6ac9d0e03ade0c6b435285ae1014 | [log] [tgz] |
---|---|---|
author | Kevin Moore <kevmoo@google.com> | Wed Jul 31 13:09:28 2019 -0700 |
committer | Kevin Moore <kevmoo@users.noreply.github.com> | Wed Jul 31 13:15:18 2019 -0700 |
tree | d51dab2d4000f3ec750f8135af1587785b61cc1f | |
parent | 9d57ff361b9971a4d868118b3692e4290aa81dc0 [diff] |
Added example/example.dart, update README to working, valid code Fixes https://github.com/dart-lang/string_scanner/issues/9
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'; import 'package:string_scanner/string_scanner.dart'; num parseNumber(String source) { // Scan a number ("1", "1.5", "-3"). var 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. var 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+")); var 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; }