diff options
Diffstat (limited to 'include/ruby/internal/iterator.h')
| -rw-r--r-- | include/ruby/internal/iterator.h | 481 |
1 files changed, 464 insertions, 17 deletions
diff --git a/include/ruby/internal/iterator.h b/include/ruby/internal/iterator.h index a2aee15d31..5f706460f8 100644 --- a/include/ruby/internal/iterator.h +++ b/include/ruby/internal/iterator.h @@ -17,49 +17,496 @@ * 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. + * 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; -VALUE rb_each(VALUE); -VALUE rb_yield(VALUE); +/** + * 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); -VALUE rb_yield_splat(VALUE); -VALUE rb_yield_splat_kw(VALUE, int); + +/** + * 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); -VALUE rb_iterate(VALUE(*)(VALUE),VALUE,rb_block_call_func_t,VALUE); -DEPRECATED_BY(rb_block_call since 1.9, VALUE rb_iterate(VALUE(*)(VALUE),VALUE,rb_block_call_func_t,VALUE)); -VALUE rb_block_call(VALUE,ID,int,const VALUE*,rb_block_call_func_t,VALUE); -VALUE rb_block_call_kw(VALUE,ID,int,const VALUE*,rb_block_call_func_t,VALUE,int); -VALUE rb_rescue(VALUE(*)(VALUE),VALUE,VALUE(*)(VALUE,VALUE),VALUE); -VALUE rb_rescue2(VALUE(*)(VALUE),VALUE,VALUE(*)(VALUE,VALUE),VALUE,...); -VALUE rb_vrescue2(VALUE(*)(VALUE),VALUE,VALUE(*)(VALUE,VALUE),VALUE,va_list); -VALUE rb_ensure(VALUE(*)(VALUE),VALUE,VALUE(*)(VALUE),VALUE); -VALUE rb_catch(const char*,rb_block_call_func_t,VALUE); -VALUE rb_catch_obj(VALUE,rb_block_call_func_t,VALUE); + +#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() -void rb_throw(const char*,VALUE); +/** + * 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() -void rb_throw_obj(VALUE,VALUE); +/** + * 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() |