diff options
author | knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-09-02 14:56:06 +0000 |
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committer | knu <knu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2013-09-02 14:56:06 +0000 |
commit | fd4b5b8dc83e61bbbb62fa7e6194c0ece6b9349f (patch) | |
tree | 4668b505d912b4b1fdbdd7bfca8599fe7f495b1f /numeric.c | |
parent | a94833eb503358ac3fe434e13be41007b92558b1 (diff) | |
download | ruby-fd4b5b8dc83e61bbbb62fa7e6194c0ece6b9349f.tar.gz |
Enhance Numeric#step.
* numeric.c (num_step): Default the limit argument to infinity and
allow it to be omitted. Keyword arguments (by: and to:) are
introduced for ease of use. [Feature #8838] [ruby-dev:47662]
[ruby-dev:42194]
* numeric.c (num_step): Optimize for infinite loop.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42781 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'numeric.c')
-rw-r--r-- | numeric.c | 116 |
1 files changed, 76 insertions, 40 deletions
@@ -115,6 +115,8 @@ VALUE rb_cFixnum; VALUE rb_eZeroDivError; VALUE rb_eFloatDomainError; +static VALUE sym_to, sym_by; + void rb_num_zerodiv(void) { @@ -1844,24 +1846,59 @@ ruby_num_interval_step_size(VALUE from, VALUE to, VALUE step, int excl) } } +#define NUM_STEP_SCAN_ARGS(argc, argv, to, step, hash, desc, inf) do { \ + argc = rb_scan_args(argc, argv, "02:", &to, &step, &hash); \ + if (!NIL_P(hash)) { \ + step = rb_hash_aref(hash, sym_by); \ + to = rb_hash_aref(hash, sym_to); \ + } \ + else { \ + /* compatibility */ \ + if (rb_equal(step, INT2FIX(0))) { \ + rb_raise(rb_eArgError, "step can't be 0"); \ + } \ + } \ + if (NIL_P(step)) step = INT2FIX(1); \ + desc = negative_int_p(step); \ + if (NIL_P(to)) to = desc ? DBL2NUM(-INFINITY) : DBL2NUM(INFINITY); \ + if (TYPE(to) == T_FLOAT) { \ + double f = RFLOAT_VALUE(to); \ + inf = isinf(f) && (signbit(f) ? desc : !desc); \ + } \ + else inf = 0; \ +} while (0) + static VALUE num_step_size(VALUE from, VALUE args, VALUE eobj) { - VALUE to = RARRAY_AREF(args, 0); - VALUE step = (RARRAY_LEN(args) > 1) ? RARRAY_AREF(args, 1) : INT2FIX(1); + VALUE to, step, hash; + int desc, inf; + int argc = args ? RARRAY_LENINT(args) : 0; + VALUE *argv = args ? RARRAY_PTR(args) : 0; + + NUM_STEP_SCAN_ARGS(argc, argv, to, step, hash, desc, inf); + return ruby_num_interval_step_size(from, to, step, FALSE); } /* * call-seq: - * num.step(limit[, step]) {|i| block } -> self - * num.step(limit[, step]) -> an_enumerator + * num.step(by: step, to: limit]) {|i| block } -> self + * num.step(by: step, to: limit]) -> an_enumerator + * num.step(limit=nil, step=1) {|i| block } -> self + * num.step(limit=nil, step=1) -> an_enumerator * * Invokes the given block with the sequence of numbers starting at +num+, * incremented by +step+ (defaulted to +1+) on each call. * * The loop finishes when the value to be passed to the block is greater than * +limit+ (if +step+ is positive) or less than +limit+ (if +step+ is - * negative). + * negative), where <i>limit</i> is defaulted to infinity. + * + * In the recommended keyword argument style, either or both of + * +step+ and +limit+ (default infinity) can be omitted. In the + * fixed position argument style, integer zero as a step + * (i.e. num.step(limit, 0)) is not allowed for historical + * compatibility reasons. * * If all the arguments are integers, the loop operates using an integer * counter. @@ -1882,11 +1919,17 @@ num_step_size(VALUE from, VALUE args, VALUE eobj) * * For example: * + * p 1.step.take(4) + * p 10.step(by: -1).take(4) + * 3.step(to: 5) { |i| print i, " " } * 1.step(10, 2) { |i| print i, " " } - * Math::E.step(Math::PI, 0.2) { |f| print f, " " } + * Math::E.step(to: Math::PI, by: 0.2) { |f| print f, " " } * * Will produce: * + * [1, 2, 3, 4] + * [10, 9, 8, 7] + * 3 4 5 * 1 3 5 7 9 * 2.71828182845905 2.91828182845905 3.11828182845905 */ @@ -1894,56 +1937,46 @@ num_step_size(VALUE from, VALUE args, VALUE eobj) static VALUE num_step(int argc, VALUE *argv, VALUE from) { - VALUE to, step; + VALUE to, step, hash; + int desc, inf; RETURN_SIZED_ENUMERATOR(from, argc, argv, num_step_size); - if (argc == 1) { - to = argv[0]; - step = INT2FIX(1); - } - else { - rb_check_arity(argc, 1, 2); - to = argv[0]; - step = argv[1]; - if (rb_equal(step, INT2FIX(0))) { - rb_raise(rb_eArgError, "step can't be 0"); - } - } - if (FIXNUM_P(from) && FIXNUM_P(to) && FIXNUM_P(step)) { - long i, end, diff; + NUM_STEP_SCAN_ARGS(argc, argv, to, step, hash, desc, inf); - i = FIX2LONG(from); - end = FIX2LONG(to); - diff = FIX2LONG(step); + if (FIXNUM_P(from) && (inf || FIXNUM_P(to)) && FIXNUM_P(step)) { + long i = FIX2LONG(from); + long diff = FIX2LONG(step); - if (diff > 0) { - while (i <= end) { + if (inf) { + for (;; i += diff) rb_yield(LONG2FIX(i)); - i += diff; - } } else { - while (i >= end) { - rb_yield(LONG2FIX(i)); - i += diff; + long end = FIX2LONG(to); + + if (desc) { + for (; i >= end; i += diff) + rb_yield(LONG2FIX(i)); + } + else { + for (; i <= end; i += diff) + rb_yield(LONG2FIX(i)); } } } else if (!ruby_float_step(from, to, step, FALSE)) { VALUE i = from; - ID cmp; - if (positive_int_p(step)) { - cmp = '>'; + if (inf) { + for (;; i = rb_funcall(i, '+', 1, step)) + rb_yield(i); } else { - cmp = '<'; - } - for (;;) { - if (RTEST(rb_funcall(i, cmp, 1, to))) break; - rb_yield(i); - i = rb_funcall(i, '+', 1, step); + ID cmp = desc ? '<' : '>'; + + for (; !RTEST(rb_funcall(i, cmp, 1, to)); i = rb_funcall(i, '+', 1, step)) + rb_yield(i); } } return from; @@ -4041,4 +4074,7 @@ Init_Numeric(void) rb_define_method(rb_cFloat, "nan?", flo_is_nan_p, 0); rb_define_method(rb_cFloat, "infinite?", flo_is_infinite_p, 0); rb_define_method(rb_cFloat, "finite?", flo_is_finite_p, 0); + + sym_to = ID2SYM(rb_intern("to")); + sym_by = ID2SYM(rb_intern("by")); } |