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author | initial.commit <initial.commit@0039d316-1c4b-4281-b951-d872f2087c98> | 2008-07-26 21:49:38 +0000 |
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committer | initial.commit <initial.commit@0039d316-1c4b-4281-b951-d872f2087c98> | 2008-07-26 21:49:38 +0000 |
commit | d7cae12696b96500c05dd2d430f6238922c20c96 (patch) | |
tree | ecff27b367735535b2a66477f8cd89d3c462a6c0 /base/string_tokenizer.h | |
parent | ee2815e28d408216cf94e874825b6bcf76c69083 (diff) | |
download | chromium_src-d7cae12696b96500c05dd2d430f6238922c20c96.zip chromium_src-d7cae12696b96500c05dd2d430f6238922c20c96.tar.gz chromium_src-d7cae12696b96500c05dd2d430f6238922c20c96.tar.bz2 |
Add base to the repository.
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'base/string_tokenizer.h')
-rw-r--r-- | base/string_tokenizer.h | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/base/string_tokenizer.h b/base/string_tokenizer.h new file mode 100644 index 0000000..9b0c468 --- /dev/null +++ b/base/string_tokenizer.h @@ -0,0 +1,225 @@ +// Copyright 2008, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifndef BASE_STRING_TOKENIZER_H__ +#define BASE_STRING_TOKENIZER_H__ + +#include <string> + +// StringTokenizerT is a simple string tokenizer class. It works like an +// iterator that with each step (see the Advance method) updates members that +// refer to the next token in the input string. The user may optionally +// configure the tokenizer to return delimiters. +// +// +// EXAMPLE 1: +// +// StringTokenizer t("this is a test", " "); +// while (t.GetNext()) { +// printf("%s\n", t.token().c_str()); +// } +// +// Output: +// +// this +// is +// a +// test +// +// +// EXAMPLE 2: +// +// StringTokenizer t("no-cache=\"foo, bar\", private", ", "); +// t.set_quote_chars("\""); +// while (t.GetNext()) { +// printf("%s\n", t.token().c_str()); +// } +// +// Output: +// +// no-cache="foo, bar" +// private +// +// +// EXAMPLE 3: +// +// bool next_is_option = false, next_is_value = false; +// std::string input = "text/html; charset=UTF-8; foo=bar"; +// StringTokenizer t(input, "; ="); +// t.set_options(StringTokenizer::RETURN_DELIMS); +// while (t.GetNext()) { +// if (t.token_is_delim()) { +// switch (*t.token_begin()) { +// case ';': +// next_is_option = true; +// break; +// case '=': +// next_is_value = true; +// break; +// } +// } else { +// const char* label; +// if (next_is_option) { +// label = "option-name"; +// next_is_option = false; +// } else if (next_is_value) { +// label = "option-value"; +// next_is_value = false; +// } else { +// label = "mime-type"; +// } +// printf("%s: %s\n", label, t.token().c_str()); +// } +// } +// +// +template <class str> +class StringTokenizerT { + public: + typedef typename str::const_iterator const_iterator; + typedef typename str::value_type char_type; + + // Options that may be pass to set_options() + enum { + // Specifies the delimiters should be returned as tokens + RETURN_DELIMS = 1 << 0, + }; + + StringTokenizerT(const str& string, + const str& delims) { + Init(string.begin(), string.end(), delims); + } + + StringTokenizerT(const_iterator string_begin, + const_iterator string_end, + const str& delims) { + Init(string_begin, string_end, delims); + } + + // Set the options for this tokenizer. By default, this is 0. + void set_options(int options) { options_ = options; } + + // Set the characters to regard as quotes. By default, this is empty. When + // a quote char is encountered, the tokenizer will switch into a mode where + // it ignores delimiters that it finds. It switches out of this mode once it + // finds another instance of the quote char. If a backslash is encountered + // within a quoted string, then the next character is skipped. + void set_quote_chars(const std::string& quotes) { quotes_ = quotes; } + + // Call this method to advance the tokenizer to the next delimiter. This + // returns false if the tokenizer is complete. This method must be called + // before calling any of the token* methods. + bool GetNext() { + AdvanceState state; + token_is_delim_ = false; + for (;;) { + token_begin_ = token_end_; + if (token_end_ == end_) + return false; + ++token_end_; + if (AdvanceOne(&state, *token_begin_)) + break; + if (options_ & RETURN_DELIMS) { + token_is_delim_ = true; + return true; + } + // else skip over delim + } + while (token_end_ != end_ && AdvanceOne(&state, *token_end_)) + ++token_end_; + return true; + } + + // Returns true if token is a delimiter. When the tokenizer is constructed + // with the RETURN_DELIMS option, this method can be used to check if the + // returned token is actually a delimiter. + bool token_is_delim() const { return token_is_delim_; } + + // If GetNext() returned true, then these methods may be used to read the + // value of the token. + const_iterator token_begin() const { return token_begin_; } + const_iterator token_end() const { return token_end_; } + str token() const { return str(token_begin_, token_end_); } + + private: + void Init(const_iterator string_begin, + const_iterator string_end, + const str& delims) { + token_end_ = string_begin; + end_ = string_end; + delims_ = delims; + options_ = 0; + } + + bool IsDelim(char_type c) const { + return delims_.find(c) != str::npos; + } + + bool IsQuote(char_type c) const { + return quotes_.find(c) != str::npos; + } + + struct AdvanceState { + bool in_quote; + bool in_escape; + char_type quote_char; + AdvanceState() : in_quote(false), in_escape(false) {} + }; + + // Returns true if a delimiter was not hit. + bool AdvanceOne(AdvanceState* state, char_type c) { + if (state->in_quote) { + if (state->in_escape) { + state->in_escape = false; + } else if (c == '\\') { + state->in_escape = true; + } else if (c == state->quote_char) { + state->in_quote = false; + } + } else { + if (IsDelim(c)) + return false; + state->in_quote = IsQuote(state->quote_char = c); + } + return true; + } + + const_iterator token_begin_; + const_iterator token_end_; + const_iterator end_; + str delims_; + str quotes_; + int options_; + bool token_is_delim_; +}; + +typedef StringTokenizerT<std::string> StringTokenizer; +typedef StringTokenizerT<std::wstring> WStringTokenizer; + +#endif // BASE_STRING_TOKENIZER_H__ |