AlkantarClanX12
Current Path : /opt/alt/ruby32/include/ruby/internal/core/ |
Current File : //opt/alt/ruby32/include/ruby/internal/core/rmatch.h |
#ifndef RBIMPL_RMATCH_H /*-*-C++-*-vi:se ft=cpp:*/ #define RBIMPL_RMATCH_H /** * @file * @author Ruby developers <ruby-core@ruby-lang.org> * @copyright This file is a part of the programming language Ruby. * Permission is hereby granted, to either redistribute and/or * modify this file, provided that the conditions mentioned in the * file COPYING are met. Consult the file for details. * @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are * implementation details. Don't take them as canon. They could * rapidly appear then vanish. The name (path) of this header file * is also an implementation detail. Do not expect it to persist * at the place it is now. Developers are free to move it anywhere * anytime at will. * @note To ruby-core: remember that this header can be possibly * recursively included from extension libraries written in C++. * Do not expect for instance `__VA_ARGS__` is always available. * We assume C99 for ruby itself but we don't assume languages of * extension libraries. They could be written in C++98. * @brief Defines struct ::RMatch. */ #include "ruby/internal/attr/artificial.h" #include "ruby/internal/attr/pure.h" #include "ruby/internal/cast.h" #include "ruby/internal/core/rbasic.h" #include "ruby/internal/value.h" #include "ruby/internal/value_type.h" #include "ruby/assert.h" /** * Convenient casting macro. * * @param obj An object, which is in fact an ::RMatch. * @return The passed object casted to ::RMatch. */ #define RMATCH(obj) RBIMPL_CAST((struct RMatch *)(obj)) /** @cond INTERNAL_MACRO */ #define RMATCH_REGS RMATCH_REGS /** @endcond */ struct re_patter_buffer; /* a.k.a. OnigRegexType, defined in onigmo.h */ struct re_registers; /* Also in onigmo.h */ /** * @old{re_pattern_buffer} * * @internal * * @shyouhei wonders: is anyone actively using this typedef ...? */ typedef struct re_pattern_buffer Regexp; /** * Represents the region of a capture group. This is basically for caching * purpose. re_registers have similar concepts (`beg` and `end`) but they are * in `ptrdiff_t*`. In order for us to implement `MatchData#offset` that info * has to be converted to offset integers. This is the struct to hold such * things. * * @internal * * But why on earth it has to be visible from extension libraries? */ struct rmatch_offset { long beg; /**< Beginning of a group. */ long end; /**< End of a group. */ }; /** Represents a match. */ struct rmatch { /** * "Registers" of a match. This is a quasi-opaque struct that holds * execution result of a match. Roughly resembles `&~`. */ struct re_registers regs; /** Capture group offsets, in C array. */ struct rmatch_offset *char_offset; /** Number of ::rmatch_offset that ::rmatch::char_offset holds. */ int char_offset_num_allocated; }; /** * Regular expression execution context. When a regular expression "matches" * to a string, it generates capture groups etc. This struct holds that info. * Visible from Ruby as an instance of `MatchData`. * * @note There is no way for extension libraries to manually generate this * struct except by actually exercising the match operation of a regular * expression. */ struct RMatch { /** Basic part, including flags and class. */ struct RBasic basic; /** * The target string that the match was made against. */ VALUE str; /** * The result of this match. */ struct rmatch *rmatch; /** * The expression of this match. */ VALUE regexp; /* RRegexp */ }; RBIMPL_ATTR_PURE_UNLESS_DEBUG() RBIMPL_ATTR_ARTIFICIAL() /** * Queries the raw ::re_registers. * * @param[in] match A match object * @pre `match` must be of ::RMatch. * @return Its execution result. * @note Good. So you are aware of the fact that it could return NULL. * Yes. It actually does. This is a really bizarre thing. The * situation is about `String#gsub` and its family. They take * strings as arguments, like `"foo".sub("bar", "baz")`. On such * situations, in order to optimise memory allocations, these * methods do not involve regular expressions at all. They just * sequentially scan the receiver. Okay. The story begins here. * Even when they do not kick our regexp engine, there must be * backref objects e.g. `$&`. But how? You know what? Ruby fakes * them. It allocates an empty ::RMatch and behaves as if there * were execution contexts. In reality there weren't. No * ::re_registers are allocated then. There is no way for this * function but to return NULL for those fake ::RMatch. This is * the reason for the nullability of this function. */ static inline struct re_registers * RMATCH_REGS(VALUE match) { RBIMPL_ASSERT_TYPE(match, RUBY_T_MATCH); RBIMPL_ASSERT_OR_ASSUME(RMATCH(match)->rmatch != NULL); return &RMATCH(match)->rmatch->regs; } #endif /* RBIMPL_RMATCH_H */