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#ifndef RBIMPL_ITERATOR_H /*-*-C++-*-vi:se ft=cpp:*/
#define RBIMPL_ITERATOR_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 Block related APIs.
*/
#include "ruby/internal/attr/deprecated.h"
#include "ruby/internal/attr/noreturn.h"
#include "ruby/internal/dllexport.h"
#include "ruby/internal/value.h"
RBIMPL_SYMBOL_EXPORT_BEGIN()
/**
* @private
*
* @deprecated This macro once was a thing in the old days, but makes no sense
* any longer today. Exists here for backwards compatibility
* only. You can safely forget about it.
*/
#define RB_BLOCK_CALL_FUNC_STRICT 1
/**
* @private
*
* @deprecated This macro once was a thing in the old days, but makes no sense
* any longer today. Exists here for backwards compatibility
* only. You can safely forget about it.
*/
#define RUBY_BLOCK_CALL_FUNC_TAKES_BLOCKARG 1
/**
* Shim for block function parameters. Historically ::rb_block_call_func_t had
* only two parameters. Over time it evolved to have much more than that. By
* using this macro you can absorb such API differences.
*
* ```CXX
* // This works since 2.1.0
* VALUE my_own_iterator(RB_BLOCK_CALL_FUNC_ARGLIST(y, c));
* ```
*/
#define RB_BLOCK_CALL_FUNC_ARGLIST(yielded_arg, callback_arg) \
VALUE yielded_arg, VALUE callback_arg, int argc, const VALUE *argv, VALUE blockarg
/**
* This is the type of a function that the interpreter expect for C-backended
* blocks. Blocks are often written in Ruby. But C extensions might want to
* have their own blocks. In order to do so authors have to create a separate
* C function of this type, and pass its pointer to rb_block_call().
*
* ```CXX
* VALUE
* my_own_iterator(RB_BLOCK_CALL_FUNC_ARGLIST(y, c))
* {
* const auto plus = rb_intern("+");
* return rb_funcall(c, plus, 1, y);
* }
*
* VALUE
* my_own_method(VALUE self)
* {
* const auto each = rb_intern("each");
* return rb_block_call(self, each, 0, 0, my_own_iterator, self);
* }
* ```
*/
typedef VALUE rb_block_call_func(RB_BLOCK_CALL_FUNC_ARGLIST(yielded_arg, callback_arg));
/**
* Shorthand type that represents an iterator-written-in-C function pointer.
*/
typedef rb_block_call_func *rb_block_call_func_t;
/**
* This is a shorthand of calling `obj.each`.
*
* @param[in] obj The receiver.
* @return What `obj.each` returns.
*
* @internal
*
* Does anyone still need it? This API was to use with rb_iterate(), which is
* marked deprecated (see below). Old idiom to call an iterator was:
*
* ```CXX
* VALUE recv;
* VALUE iter_func(ANYARGS);
* VALUE iter_data;
* rb_iterate(rb_each, recv, iter_func, iter_data);
* ```
*/
VALUE rb_each(VALUE obj);
/**
* Yields the block. In Ruby there is a concept called a block. You can pass
* one to a method. In a method, when called with a block, you can yield it
* using this function.
*
* ```CXX
* VALUE
* iterate(VALUE self)
* {
* extern int get_n(VALUE);
* extern VALUE get_v(VALUE, VALUE);
* const auto n = get_n(self);
*
* for (int i=0; i<n; i++) {
* auto v = get_v(self, i);
*
* rb_yield(v);
* }
* return self;
* }
* ```
*
* @param[in] val Passed to the block.
* @exception rb_eLocalJumpError There is no block given.
* @return Evaluated value of the given block.
*/
VALUE rb_yield(VALUE val);
/**
* Identical to rb_yield(), except it takes variadic number of parameters and
* pass them to the block.
*
* @param[in] n Number of parameters.
* @param[in] ... List of arguments passed to the block.
* @exception rb_eLocalJumpError There is no block given.
* @return Evaluated value of the given block.
*/
VALUE rb_yield_values(int n, ...);
/**
* Identical to rb_yield_values(), except it takes the parameters as a C array
* instead of variadic arguments.
*
* @param[in] n Number of parameters.
* @param[in] argv List of arguments passed to the block.
* @exception rb_eLocalJumpError There is no block given.
* @return Evaluated value of the given block.
*/
VALUE rb_yield_values2(int n, const VALUE *argv);
/**
* Identical to rb_yield_values2(), except you can specify how to handle the
* last element of the given array.
*
* @param[in] n Number of parameters.
* @param[in] argv List of arguments passed to the block.
* @param[in] kw_splat Handling of keyword parameters:
* - RB_NO_KEYWORDS `ary`'s last is not a keyword argument.
* - RB_PASS_KEYWORDS `ary`'s last is a keyword argument.
* - RB_PASS_CALLED_KEYWORDS makes no sense here.
* @exception rb_eLocalJumpError There is no block given.
* @return Evaluated value of the given block.
*/
VALUE rb_yield_values_kw(int n, const VALUE *argv, int kw_splat);
/**
* Identical to rb_yield_values(), except it splats an array to generate the
* list of parameters.
*
* @param[in] ary Array to splat.
* @exception rb_eLocalJumpError There is no block given.
* @return Evaluated value of the given block.
*/
VALUE rb_yield_splat(VALUE ary);
/**
* Identical to rb_yield_splat(), except you can specify how to handle the last
* element of the given array.
*
* @param[in] ary Array to splat.
* @param[in] kw_splat Handling of keyword parameters:
* - RB_NO_KEYWORDS `ary`'s last is not a keyword argument.
* - RB_PASS_KEYWORDS `ary`'s last is a keyword argument.
* - RB_PASS_CALLED_KEYWORDS makes no sense here.
* @exception rb_eLocalJumpError There is no block given.
* @return Evaluated value of the given block.
*/
VALUE rb_yield_splat_kw(VALUE ary, int kw_splat);
/**
* Pass a passed block.
*
* Sometimes you want to "pass" a block form one method to another. Suppose
* you have this Ruby method `foo`:
*
* ```ruby
* def foo(x, y)
* x.open(y) do |*z|
* yield(*z)
* end
* end
* ```
*
* And suppose you want to translate this into C. Then rb_yield_block()
* function is usable in this situation.
*
* ```CXX
* VALUE
* foo_translated_into_C(VALUE self, VALUE x, VALUE y)
* {
* const auto open = rb_intern("open");
*
* return rb_block_call(x, open, 1, &y, rb_yield_block, Qfalse);
* // ^^^^^^^^^^^^^^ Here.
* }
* ```
*
* @see rb_funcall_passing_block
*
* @internal
*
* @shyouhei honestly doesn't understand why this is needed, given there
* already was rb_funcall_passing_block() at the time it was implemented. If
* somebody knows its raison d'etre, please improve the document :FIXME:
*/
VALUE rb_yield_block(RB_BLOCK_CALL_FUNC_ARGLIST(yielded_arg, callback_arg)); /* rb_block_call_func */
/**
* Determines if the current method is given a keyword argument.
*
* @retval false No keyword argument is given.
* @retval true Keyword argument(s) are given.
* @ingroup defmethod
*/
int rb_keyword_given_p(void);
/**
* Determines if the current method is given a block.
*
* @retval false No block is given.
* @retval true A block is given.
* @ingroup defmethod
*
* @internal
*
* This function should have returned a bool. But at the time it was designed
* the project was entirely written in K&R C.
*/
int rb_block_given_p(void);
/**
* Declares that the current method needs a block.
*
* @exception rb_eLocalJumpError No block given.
* @ingroup defmethod
*/
void rb_need_block(void);
#ifndef __cplusplus
RBIMPL_ATTR_DEPRECATED(("by: rb_block_call since 1.9"))
#endif
/**
* Old way to iterate a block.
*
* @deprecated This is an old API. Use rb_block_call() instead.
* @warning The passed function must at least once call a ruby method
* (to handle interrupts etc.)
* @param[in] func1 A function that could yield a value.
* @param[in,out] data1 Passed to `func1`
* @param[in] proc A function acts as a block.
* @param[in,out] data2 Passed to `proc` as the data2 parameter.
* @return What `func1` returns.
*/
VALUE rb_iterate(VALUE (*func1)(VALUE), VALUE data1, rb_block_call_func_t proc, VALUE data2);
#ifdef __cplusplus
namespace ruby {
namespace backward {
/**
* Old way to iterate a block.
*
* @deprecated This is an old API. Use rb_block_call() instead.
* @warning The passed function must at least once call a ruby method
* (to handle interrupts etc.)
* @param[in] iter A function that could yield a value.
* @param[in,out] data1 Passed to `func1`
* @param[in] bl A function acts as a block.
* @param[in,out] data2 Passed to `proc` as the data2 parameter.
* @return What `func1` returns.
*/
static inline VALUE
rb_iterate_deprecated(VALUE (*iter)(VALUE), VALUE data1, rb_block_call_func_t bl, VALUE data2)
{
return ::rb_iterate(iter, data1, bl, data2);
}}}
RBIMPL_ATTR_DEPRECATED(("by: rb_block_call since 1.9"))
VALUE rb_iterate(VALUE (*func1)(VALUE), VALUE data1, rb_block_call_func_t proc, VALUE data2);
#endif
/**
* Identical to rb_funcallv(), except it additionally passes a function as a
* block. When the method yields, `proc` is called with the yielded value as
* its first argument, and `data2` as the second. Yielded values would be
* packed into an array if multiple values are yielded at once.
*
* @param[in,out] obj Receiver.
* @param[in] mid Method signature.
* @param[in] argc Number of arguments.
* @param[in] argv Arguments passed to `obj.mid`.
* @param[in] proc A function acts as a block.
* @param[in,out] data2 Passed to `proc` as the data2 parameter.
* @return What `obj.mid` returns.
*/
VALUE rb_block_call(VALUE obj, ID mid, int argc, const VALUE *argv, rb_block_call_func_t proc, VALUE data2);
/**
* Identical to rb_funcallv_kw(), except it additionally passes a function as a
* block. It can also be seen as a routine identical to rb_block_call(),
* except it handles keyword-ness of `argv[argc-1]`.
*
* @param[in,out] obj Receiver.
* @param[in] mid Method signature.
* @param[in] argc Number of arguments including the keywords.
* @param[in] argv Arguments passed to `obj.mid`.
* @param[in] proc A function acts as a block.
* @param[in,out] data2 Passed to `proc` as the data2 parameter.
* @param[in] kw_splat Handling of keyword parameters:
* - RB_NO_KEYWORDS `argv`'s last is not a keyword argument.
* - RB_PASS_KEYWORDS `argv`'s last is a keyword argument.
* - RB_PASS_CALLED_KEYWORDS it depends if there is a passed block.
* @return What `obj.mid` returns.
*/
VALUE rb_block_call_kw(VALUE obj, ID mid, int argc, const VALUE *argv, rb_block_call_func_t proc, VALUE data2, int kw_splat);
/**
* Identical to rb_rescue2(), except it does not take a list of exception
* classes. This is a shorthand of:
*
* ```CXX
* rb_rescue2(b_proc, data1, r_proc, data2, rb_eStandardError, (VALUE)0);
* ```
*
* @param[in] b_proc A function which potentially raises an exception.
* @param[in,out] data1 Passed to `b_proc`.
* @param[in] r_proc A function which rescues an exception in `b_proc`.
* @param[in,out] data2 The first argument of `r_proc`.
* @return The return value of `b_proc` if no exception occurs, or the
* return value of `r_proc` otherwise.
* @see rb_rescue
* @see rb_ensure
* @see rb_protect
* @ingroup exception
*/
VALUE rb_rescue(VALUE (*b_proc)(VALUE), VALUE data1, VALUE (*r_proc)(VALUE, VALUE), VALUE data2);
/**
* An equivalent of `rescue` clause.
*
* First it calls the function `b_proc` with `data1` as the argument. If
* nothing is thrown the function happily returns the return value of `b_proc`.
* When `b_proc` raises an exception, and the exception is a kind of one of the
* given exception classes, it then calls `r_proc` with `data2` and that
* exception. If the exception does not match any of them, it propagates.
*
* @param[in] b_proc A function which potentially raises an exception.
* @param[in,out] data1 Passed to `b_proc`.
* @param[in] r_proc A function which rescues an exception in `b_proc`.
* @param[in,out] data2 The first argument of `r_proc`.
* @param[in] ... 1 or more exception classes. Must be terminated by
* `(VALUE)0`
* @return The return value of `b_proc` if no exception occurs, or the
* return value of `r_proc` otherwise.
* @see rb_rescue
* @see rb_ensure
* @see rb_protect
* @ingroup exception
*/
VALUE rb_rescue2(VALUE (*b_proc)(VALUE), VALUE data1, VALUE (*r_proc)(VALUE, VALUE), VALUE data2, ...);
/**
* Identical to rb_rescue2(), except it takes `va_list` instead of variadic
* number of arguments. This is exposed to 3rd parties because inline
* functions use it. Basically you don't have to bother.
*
* @param[in] b_proc A function which potentially raises an exception.
* @param[in,out] data1 Passed to `b_proc`.
* @param[in] r_proc A function which rescues an exception in `b_proc`.
* @param[in,out] data2 The first argument of `r_proc`.
* @param[in] ap 1 or more exception classes. Must be terminated by
* `(VALUE)0`
* @return The return value of `b_proc` if no exception occurs, or the
* return value of `r_proc` otherwise.
* @see rb_rescue
* @see rb_ensure
* @see rb_protect
* @ingroup exception
*/
VALUE rb_vrescue2(VALUE (*b_proc)(VALUE), VALUE data1, VALUE (*r_proc)(VALUE, VALUE), VALUE data2, va_list ap);
/**
* An equivalent to `ensure` clause. Calls the function `b_proc` with `data1`
* as the argument, then calls `e_proc` with `data2` when execution terminated.
*
* @param[in] b_proc A function representing begin clause.
* @param[in,out] data1 Passed to `b_proc`.
* @param[in] e_proc A function representing ensure clause.
* @param[in,out] data2 Passed to `e_proc`.
* @retval RUBY_Qnil exception occurred inside of `b_proc`.
* @retval otherwise The return value of `b_proc`.
* @see rb_rescue
* @see rb_rescue2
* @see rb_protect
* @ingroup exception
*/
VALUE rb_ensure(VALUE (*b_proc)(VALUE), VALUE data1, VALUE (*e_proc)(VALUE), VALUE data2);
/**
* Executes the passed block and catches values thrown from inside of it.
*
* In case the block does not contain any throw`, this function returns the
* value of the last expression evaluated.
*
* ```CXX
* VALUE
* iter(RB_BLOCK_CALL_FUNC_ARGLIST(yielded, callback))
* {
* return INT2FIX(123);
* }
*
* VALUE
* method(VALUE self)
* {
* return rb_catch("tag", iter, Qnil); // returns 123
* }
* ```
*
* In case there do exist `throw`, Ruby searches up its execution context for a
* `catch` block. When a matching catch is found, the block stops executing
* and returns that thrown value instead.
*
* ```CXX
* VALUE
* iter(RB_BLOCK_CALL_FUNC_ARGLIST(yielded, callback))
* {
* rb_throw("tag", 456);
* return INT2FIX(123);
* }
*
* VALUE
* method(VALUE self)
* {
* return rb_catch("tag", iter, Qnil); // returns 456
* }
* ```
*
* @param[in] tag Arbitrary tag string.
* @param[in] func Function pointer that acts as a block.
* @param[in,out] data Extra parameter passed to `func`.
* @return Either caught value for `tag`, or the return value of `func`
* if nothing is thrown.
*/
VALUE rb_catch(const char *tag, rb_block_call_func_t func, VALUE data);
/**
* Identical to rb_catch(), except it catches arbitrary Ruby objects.
*
* @param[in] tag Arbitrary tag object.
* @param[in] func Function pointer that acts as a block.
* @param[in,out] data Extra parameter passed to `func`.
* @return Either caught value for `tag`, or the return value of `func`
* if nothing is thrown.
*/
VALUE rb_catch_obj(VALUE tag, rb_block_call_func_t func, VALUE data);
RBIMPL_ATTR_NORETURN()
/**
* Transfers control to the end of the active `catch` block waiting for `tag`.
* Raises rb_eUncughtThrow if there is no `catch` block for the tag. The
* second parameter supplies a return value for the `catch` block, which
* otherwise defaults to ::RUBY_Qnil. For examples, see rb_catch().
*
* @param[in] tag Tag string.
* @param[in] val Value to throw.
* @exception rb_eUncughtThrow There is no corresponding `catch` clause.
* @note It never returns.
*/
void rb_throw(const char *tag, VALUE val);
RBIMPL_ATTR_NORETURN()
/**
* Identical to rb_throw(), except it allows arbitrary Ruby object to become a
* tag.
*
* @param[in] tag Arbitrary object.
* @param[in] val Value to throw.
* @exception rb_eUncughtThrow There is no corresponding `catch` clause.
* @note It never returns.
*/
void rb_throw_obj(VALUE tag, VALUE val);
RBIMPL_SYMBOL_EXPORT_END()
#endif /* RBIMPL_ITERATOR_H */