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Diffstat (limited to 'third_party/abseil_cpp/absl/strings/ascii.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/strings/ascii.h | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/strings/ascii.h b/third_party/abseil_cpp/absl/strings/ascii.h new file mode 100644 index 000000000000..b46bc71f35b9 --- /dev/null +++ b/third_party/abseil_cpp/absl/strings/ascii.h @@ -0,0 +1,242 @@ +// +// 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 +// +// https://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. +// +// ----------------------------------------------------------------------------- +// File: ascii.h +// ----------------------------------------------------------------------------- +// +// This package contains functions operating on characters and strings +// restricted to standard ASCII. These include character classification +// functions analogous to those found in the ANSI C Standard Library <ctype.h> +// header file. +// +// C++ implementations provide <ctype.h> functionality based on their +// C environment locale. In general, reliance on such a locale is not ideal, as +// the locale standard is problematic (and may not return invariant information +// for the same character set, for example). These `ascii_*()` functions are +// hard-wired for standard ASCII, much faster, and guaranteed to behave +// consistently. They will never be overloaded, nor will their function +// signature change. +// +// `ascii_isalnum()`, `ascii_isalpha()`, `ascii_isascii()`, `ascii_isblank()`, +// `ascii_iscntrl()`, `ascii_isdigit()`, `ascii_isgraph()`, `ascii_islower()`, +// `ascii_isprint()`, `ascii_ispunct()`, `ascii_isspace()`, `ascii_isupper()`, +// `ascii_isxdigit()` +// Analogous to the <ctype.h> functions with similar names, these +// functions take an unsigned char and return a bool, based on whether the +// character matches the condition specified. +// +// If the input character has a numerical value greater than 127, these +// functions return `false`. +// +// `ascii_tolower()`, `ascii_toupper()` +// Analogous to the <ctype.h> functions with similar names, these functions +// take an unsigned char and return a char. +// +// If the input character is not an ASCII {lower,upper}-case letter (including +// numerical values greater than 127) then the functions return the same value +// as the input character. + +#ifndef ABSL_STRINGS_ASCII_H_ +#define ABSL_STRINGS_ASCII_H_ + +#include <algorithm> +#include <string> + +#include "absl/base/attributes.h" +#include "absl/base/config.h" +#include "absl/strings/string_view.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace ascii_internal { + +// Declaration for an array of bitfields holding character information. +ABSL_DLL extern const unsigned char kPropertyBits[256]; + +// Declaration for the array of characters to upper-case characters. +ABSL_DLL extern const char kToUpper[256]; + +// Declaration for the array of characters to lower-case characters. +ABSL_DLL extern const char kToLower[256]; + +} // namespace ascii_internal + +// ascii_isalpha() +// +// Determines whether the given character is an alphabetic character. +inline bool ascii_isalpha(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x01) != 0; +} + +// ascii_isalnum() +// +// Determines whether the given character is an alphanumeric character. +inline bool ascii_isalnum(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x04) != 0; +} + +// ascii_isspace() +// +// Determines whether the given character is a whitespace character (space, +// tab, vertical tab, formfeed, linefeed, or carriage return). +inline bool ascii_isspace(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x08) != 0; +} + +// ascii_ispunct() +// +// Determines whether the given character is a punctuation character. +inline bool ascii_ispunct(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x10) != 0; +} + +// ascii_isblank() +// +// Determines whether the given character is a blank character (tab or space). +inline bool ascii_isblank(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x20) != 0; +} + +// ascii_iscntrl() +// +// Determines whether the given character is a control character. +inline bool ascii_iscntrl(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x40) != 0; +} + +// ascii_isxdigit() +// +// Determines whether the given character can be represented as a hexadecimal +// digit character (i.e. {0-9} or {A-F}). +inline bool ascii_isxdigit(unsigned char c) { + return (ascii_internal::kPropertyBits[c] & 0x80) != 0; +} + +// ascii_isdigit() +// +// Determines whether the given character can be represented as a decimal +// digit character (i.e. {0-9}). +inline bool ascii_isdigit(unsigned char c) { return c >= '0' && c <= '9'; } + +// ascii_isprint() +// +// Determines whether the given character is printable, including whitespace. +inline bool ascii_isprint(unsigned char c) { return c >= 32 && c < 127; } + +// ascii_isgraph() +// +// Determines whether the given character has a graphical representation. +inline bool ascii_isgraph(unsigned char c) { return c > 32 && c < 127; } + +// ascii_isupper() +// +// Determines whether the given character is uppercase. +inline bool ascii_isupper(unsigned char c) { return c >= 'A' && c <= 'Z'; } + +// ascii_islower() +// +// Determines whether the given character is lowercase. +inline bool ascii_islower(unsigned char c) { return c >= 'a' && c <= 'z'; } + +// ascii_isascii() +// +// Determines whether the given character is ASCII. +inline bool ascii_isascii(unsigned char c) { return c < 128; } + +// ascii_tolower() +// +// Returns an ASCII character, converting to lowercase if uppercase is +// passed. Note that character values > 127 are simply returned. +inline char ascii_tolower(unsigned char c) { + return ascii_internal::kToLower[c]; +} + +// Converts the characters in `s` to lowercase, changing the contents of `s`. +void AsciiStrToLower(std::string* s); + +// Creates a lowercase string from a given absl::string_view. +ABSL_MUST_USE_RESULT inline std::string AsciiStrToLower(absl::string_view s) { + std::string result(s); + absl::AsciiStrToLower(&result); + return result; +} + +// ascii_toupper() +// +// Returns the ASCII character, converting to upper-case if lower-case is +// passed. Note that characters values > 127 are simply returned. +inline char ascii_toupper(unsigned char c) { + return ascii_internal::kToUpper[c]; +} + +// Converts the characters in `s` to uppercase, changing the contents of `s`. +void AsciiStrToUpper(std::string* s); + +// Creates an uppercase string from a given absl::string_view. +ABSL_MUST_USE_RESULT inline std::string AsciiStrToUpper(absl::string_view s) { + std::string result(s); + absl::AsciiStrToUpper(&result); + return result; +} + +// Returns absl::string_view with whitespace stripped from the beginning of the +// given string_view. +ABSL_MUST_USE_RESULT inline absl::string_view StripLeadingAsciiWhitespace( + absl::string_view str) { + auto it = std::find_if_not(str.begin(), str.end(), absl::ascii_isspace); + return str.substr(it - str.begin()); +} + +// Strips in place whitespace from the beginning of the given string. +inline void StripLeadingAsciiWhitespace(std::string* str) { + auto it = std::find_if_not(str->begin(), str->end(), absl::ascii_isspace); + str->erase(str->begin(), it); +} + +// Returns absl::string_view with whitespace stripped from the end of the given +// string_view. +ABSL_MUST_USE_RESULT inline absl::string_view StripTrailingAsciiWhitespace( + absl::string_view str) { + auto it = std::find_if_not(str.rbegin(), str.rend(), absl::ascii_isspace); + return str.substr(0, str.rend() - it); +} + +// Strips in place whitespace from the end of the given string +inline void StripTrailingAsciiWhitespace(std::string* str) { + auto it = std::find_if_not(str->rbegin(), str->rend(), absl::ascii_isspace); + str->erase(str->rend() - it); +} + +// Returns absl::string_view with whitespace stripped from both ends of the +// given string_view. +ABSL_MUST_USE_RESULT inline absl::string_view StripAsciiWhitespace( + absl::string_view str) { + return StripTrailingAsciiWhitespace(StripLeadingAsciiWhitespace(str)); +} + +// Strips in place whitespace from both ends of the given string +inline void StripAsciiWhitespace(std::string* str) { + StripTrailingAsciiWhitespace(str); + StripLeadingAsciiWhitespace(str); +} + +// Removes leading, trailing, and consecutive internal whitespace. +void RemoveExtraAsciiWhitespace(std::string*); + +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_STRINGS_ASCII_H_ |