Index: pkg/source_maps/lib/src/vlq.dart |
diff --git a/pkg/source_maps/lib/src/vlq.dart b/pkg/source_maps/lib/src/vlq.dart |
deleted file mode 100644 |
index e4ab4eb69c5aa28dc2009c560623344a7f43bcb0..0000000000000000000000000000000000000000 |
--- a/pkg/source_maps/lib/src/vlq.dart |
+++ /dev/null |
@@ -1,103 +0,0 @@ |
-// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
-// for details. All rights reserved. Use of this source code is governed by a |
-// BSD-style license that can be found in the LICENSE file. |
- |
- |
-/// Utilities to encode and decode VLQ values used in source maps. |
-/// |
-/// Sourcemaps are encoded with variable length numbers as base64 encoded |
-/// strings with the least significant digit coming first. Each base64 digit |
-/// encodes a 5-bit value (0-31) and a continuation bit. Signed values can be |
-/// represented by using the least significant bit of the value as the sign bit. |
-/// |
-/// For more details see the source map [version 3 documentation][spec]. |
-/// [spec]: https://docs.google.com/a/google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit |
-library source_maps.src.vlq; |
- |
-import 'dart:math'; |
- |
-const int VLQ_BASE_SHIFT = 5; |
- |
-const int VLQ_BASE_MASK = (1 << 5) - 1; |
- |
-const int VLQ_CONTINUATION_BIT = 1 << 5; |
- |
-const int VLQ_CONTINUATION_MASK = 1 << 5; |
- |
-const String BASE64_DIGITS = |
- 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'; |
- |
-final Map<String, int> _digits = () { |
- var map = <String, int>{}; |
- for (int i = 0; i < 64; i++) { |
- map[BASE64_DIGITS[i]] = i; |
- } |
- return map; |
-}(); |
- |
-final int MAX_INT32 = pow(2, 31) - 1; |
-final int MIN_INT32 = -pow(2, 31); |
- |
-/// Creates the VLQ encoding of [value] as a sequence of characters |
-Iterable<String> encodeVlq(int value) { |
- if (value < MIN_INT32 || value > MAX_INT32) { |
- throw new ArgumentError('expected 32 bit int, got: $value'); |
- } |
- var res = <String>[]; |
- int signBit = 0; |
- if (value < 0) { |
- signBit = 1; |
- value = -value; |
- } |
- value = (value << 1) | signBit; |
- do { |
- int digit = value & VLQ_BASE_MASK; |
- value >>= VLQ_BASE_SHIFT; |
- if (value > 0) { |
- digit |= VLQ_CONTINUATION_BIT; |
- } |
- res.add(BASE64_DIGITS[digit]); |
- } while (value > 0); |
- return res; |
-} |
- |
-/// Decodes a value written as a sequence of VLQ characters. The first input |
-/// character will be `chars.current` after calling `chars.moveNext` once. The |
-/// iterator is advanced until a stop character is found (a character without |
-/// the [VLQ_CONTINUATION_BIT]). |
-int decodeVlq(Iterator<String> chars) { |
- int result = 0; |
- bool stop = false; |
- int shift = 0; |
- while (!stop) { |
- if (!chars.moveNext()) throw new StateError('incomplete VLQ value'); |
- var char = chars.current; |
- if (!_digits.containsKey(char)) { |
- throw new FormatException('invalid character in VLQ encoding: $char'); |
- } |
- var digit = _digits[char]; |
- stop = (digit & VLQ_CONTINUATION_BIT) == 0; |
- digit &= VLQ_BASE_MASK; |
- result += (digit << shift); |
- shift += VLQ_BASE_SHIFT; |
- } |
- |
- // Result uses the least significant bit as a sign bit. We convert it into a |
- // two-complement value. For example, |
- // 2 (10 binary) becomes 1 |
- // 3 (11 binary) becomes -1 |
- // 4 (100 binary) becomes 2 |
- // 5 (101 binary) becomes -2 |
- // 6 (110 binary) becomes 3 |
- // 7 (111 binary) becomes -3 |
- bool negate = (result & 1) == 1; |
- result = result >> 1; |
- result = negate ? -result : result; |
- |
- // TODO(sigmund): can we detect this earlier? |
- if (result < MIN_INT32 || result > MAX_INT32) { |
- throw new FormatException( |
- 'expected an encoded 32 bit int, but we got: $result'); |
- } |
- return result; |
-} |