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Diffstat (limited to 'absl/strings/ascii.cc')
-rw-r--r-- | absl/strings/ascii.cc | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/absl/strings/ascii.cc b/absl/strings/ascii.cc new file mode 100644 index 00000000..c9481e88 --- /dev/null +++ b/absl/strings/ascii.cc @@ -0,0 +1,198 @@ +// Copyright 2017 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "absl/strings/ascii.h" + +namespace absl { +namespace ascii_internal { + +// # Table generated by this Python code (bit 0x02 is currently unused): +// TODO(mbar) Move Python code for generation of table to BUILD and link here. + +// NOTE: The kAsciiPropertyBits table used within this code was generated by +// Python code of the following form. (Bit 0x02 is currently unused and +// available.) +// +// def Hex2(n): +// return '0x' + hex(n/16)[2:] + hex(n%16)[2:] +// def IsPunct(ch): +// return (ord(ch) >= 32 and ord(ch) < 127 and +// not ch.isspace() and not ch.isalnum()) +// def IsBlank(ch): +// return ch in ' \t' +// def IsCntrl(ch): +// return ord(ch) < 32 or ord(ch) == 127 +// def IsXDigit(ch): +// return ch.isdigit() or ch.lower() in 'abcdef' +// for i in range(128): +// ch = chr(i) +// mask = ((ch.isalpha() and 0x01 or 0) | +// (ch.isalnum() and 0x04 or 0) | +// (ch.isspace() and 0x08 or 0) | +// (IsPunct(ch) and 0x10 or 0) | +// (IsBlank(ch) and 0x20 or 0) | +// (IsCntrl(ch) and 0x40 or 0) | +// (IsXDigit(ch) and 0x80 or 0)) +// print Hex2(mask) + ',', +// if i % 16 == 7: +// print ' //', Hex2(i & 0x78) +// elif i % 16 == 15: +// print + +// clang-format off +// Array of bitfields holding character information. Each bit value corresponds +// to a particular character feature. For readability, and because the value +// of these bits is tightly coupled to this implementation, the individual bits +// are not named. Note that bitfields for all characters above ASCII 127 are +// zero-initialized. +const unsigned char kPropertyBits[256] = { + 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, // 0x00 + 0x40, 0x68, 0x48, 0x48, 0x48, 0x48, 0x40, 0x40, + 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, // 0x10 + 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, + 0x28, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, // 0x20 + 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, + 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, // 0x30 + 0x84, 0x84, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, + 0x10, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x05, // 0x40 + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, // 0x50 + 0x05, 0x05, 0x05, 0x10, 0x10, 0x10, 0x10, 0x10, + 0x10, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x05, // 0x60 + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, // 0x70 + 0x05, 0x05, 0x05, 0x10, 0x10, 0x10, 0x10, 0x40, +}; + +// Array of characters for the ascii_tolower() function. For values 'A' +// through 'Z', return the lower-case character; otherwise, return the +// identity of the passed character. +const char kToLower[256] = { + '\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07', + '\x08', '\x09', '\x0a', '\x0b', '\x0c', '\x0d', '\x0e', '\x0f', + '\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17', + '\x18', '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f', + '\x20', '\x21', '\x22', '\x23', '\x24', '\x25', '\x26', '\x27', + '\x28', '\x29', '\x2a', '\x2b', '\x2c', '\x2d', '\x2e', '\x2f', + '\x30', '\x31', '\x32', '\x33', '\x34', '\x35', '\x36', '\x37', + '\x38', '\x39', '\x3a', '\x3b', '\x3c', '\x3d', '\x3e', '\x3f', + '\x40', 'a', 'b', 'c', 'd', 'e', 'f', 'g', + 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', + 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', + 'x', 'y', 'z', '\x5b', '\x5c', '\x5d', '\x5e', '\x5f', + '\x60', '\x61', '\x62', '\x63', '\x64', '\x65', '\x66', '\x67', + '\x68', '\x69', '\x6a', '\x6b', '\x6c', '\x6d', '\x6e', '\x6f', + '\x70', '\x71', '\x72', '\x73', '\x74', '\x75', '\x76', '\x77', + '\x78', '\x79', '\x7a', '\x7b', '\x7c', '\x7d', '\x7e', '\x7f', + '\x80', '\x81', '\x82', '\x83', '\x84', '\x85', '\x86', '\x87', + '\x88', '\x89', '\x8a', '\x8b', '\x8c', '\x8d', '\x8e', '\x8f', + '\x90', '\x91', '\x92', '\x93', '\x94', '\x95', '\x96', '\x97', + '\x98', '\x99', '\x9a', '\x9b', '\x9c', '\x9d', '\x9e', '\x9f', + '\xa0', '\xa1', '\xa2', '\xa3', '\xa4', '\xa5', '\xa6', '\xa7', + '\xa8', '\xa9', '\xaa', '\xab', '\xac', '\xad', '\xae', '\xaf', + '\xb0', '\xb1', '\xb2', '\xb3', '\xb4', '\xb5', '\xb6', '\xb7', + '\xb8', '\xb9', '\xba', '\xbb', '\xbc', '\xbd', '\xbe', '\xbf', + '\xc0', '\xc1', '\xc2', '\xc3', '\xc4', '\xc5', '\xc6', '\xc7', + '\xc8', '\xc9', '\xca', '\xcb', '\xcc', '\xcd', '\xce', '\xcf', + '\xd0', '\xd1', '\xd2', '\xd3', '\xd4', '\xd5', '\xd6', '\xd7', + '\xd8', '\xd9', '\xda', '\xdb', '\xdc', '\xdd', '\xde', '\xdf', + '\xe0', '\xe1', '\xe2', '\xe3', '\xe4', '\xe5', '\xe6', '\xe7', + '\xe8', '\xe9', '\xea', '\xeb', '\xec', '\xed', '\xee', '\xef', + '\xf0', '\xf1', '\xf2', '\xf3', '\xf4', '\xf5', '\xf6', '\xf7', + '\xf8', '\xf9', '\xfa', '\xfb', '\xfc', '\xfd', '\xfe', '\xff', +}; + +// Array of characters for the ascii_toupper() function. For values 'a' +// through 'z', return the upper-case character; otherwise, return the +// identity of the passed character. +const char kToUpper[256] = { + '\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07', + '\x08', '\x09', '\x0a', '\x0b', '\x0c', '\x0d', '\x0e', '\x0f', + '\x10', '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17', + '\x18', '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f', + '\x20', '\x21', '\x22', '\x23', '\x24', '\x25', '\x26', '\x27', + '\x28', '\x29', '\x2a', '\x2b', '\x2c', '\x2d', '\x2e', '\x2f', + '\x30', '\x31', '\x32', '\x33', '\x34', '\x35', '\x36', '\x37', + '\x38', '\x39', '\x3a', '\x3b', '\x3c', '\x3d', '\x3e', '\x3f', + '\x40', '\x41', '\x42', '\x43', '\x44', '\x45', '\x46', '\x47', + '\x48', '\x49', '\x4a', '\x4b', '\x4c', '\x4d', '\x4e', '\x4f', + '\x50', '\x51', '\x52', '\x53', '\x54', '\x55', '\x56', '\x57', + '\x58', '\x59', '\x5a', '\x5b', '\x5c', '\x5d', '\x5e', '\x5f', + '\x60', 'A', 'B', 'C', 'D', 'E', 'F', 'G', + 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', + 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', + 'X', 'Y', 'Z', '\x7b', '\x7c', '\x7d', '\x7e', '\x7f', + '\x80', '\x81', '\x82', '\x83', '\x84', '\x85', '\x86', '\x87', + '\x88', '\x89', '\x8a', '\x8b', '\x8c', '\x8d', '\x8e', '\x8f', + '\x90', '\x91', '\x92', '\x93', '\x94', '\x95', '\x96', '\x97', + '\x98', '\x99', '\x9a', '\x9b', '\x9c', '\x9d', '\x9e', '\x9f', + '\xa0', '\xa1', '\xa2', '\xa3', '\xa4', '\xa5', '\xa6', '\xa7', + '\xa8', '\xa9', '\xaa', '\xab', '\xac', '\xad', '\xae', '\xaf', + '\xb0', '\xb1', '\xb2', '\xb3', '\xb4', '\xb5', '\xb6', '\xb7', + '\xb8', '\xb9', '\xba', '\xbb', '\xbc', '\xbd', '\xbe', '\xbf', + '\xc0', '\xc1', '\xc2', '\xc3', '\xc4', '\xc5', '\xc6', '\xc7', + '\xc8', '\xc9', '\xca', '\xcb', '\xcc', '\xcd', '\xce', '\xcf', + '\xd0', '\xd1', '\xd2', '\xd3', '\xd4', '\xd5', '\xd6', '\xd7', + '\xd8', '\xd9', '\xda', '\xdb', '\xdc', '\xdd', '\xde', '\xdf', + '\xe0', '\xe1', '\xe2', '\xe3', '\xe4', '\xe5', '\xe6', '\xe7', + '\xe8', '\xe9', '\xea', '\xeb', '\xec', '\xed', '\xee', '\xef', + '\xf0', '\xf1', '\xf2', '\xf3', '\xf4', '\xf5', '\xf6', '\xf7', + '\xf8', '\xf9', '\xfa', '\xfb', '\xfc', '\xfd', '\xfe', '\xff', +}; +// clang-format on + +} // namespace ascii_internal + +void AsciiStrToLower(std::string* s) { + for (auto& ch : *s) { + ch = absl::ascii_tolower(ch); + } +} + +void AsciiStrToUpper(std::string* s) { + for (auto& ch : *s) { + ch = absl::ascii_toupper(ch); + } +} + +void RemoveExtraAsciiWhitespace(std::string* str) { + auto stripped = StripAsciiWhitespace(*str); + + if (stripped.empty()) { + str->clear(); + return; + } + + auto input_it = stripped.begin(); + auto input_end = stripped.end(); + auto output_it = &(*str)[0]; + bool is_ws = false; + + for (; input_it < input_end; ++input_it) { + if (is_ws) { + // Consecutive whitespace? Keep only the last. + is_ws = absl::ascii_isspace(*input_it); + if (is_ws) --output_it; + } else { + is_ws = absl::ascii_isspace(*input_it); + } + + *output_it = *input_it; + ++output_it; + } + + str->erase(output_it - &(*str)[0]); +} + +} // namespace absl |