From 981105b3e6758455646e9834b1c2695bf774a401 Mon Sep 17 00:00:00 2001 From: Tomasz Dabrowski Date: Fri, 10 Feb 2017 12:58:41 +0100 Subject: String#ljust and String#rjust reimplementation (fix #3445) - String#ljust and String#rjust are now C functions to improve performance - infinite loop because of an empty padding argument is now prevented (ArgumentError is raised) - extra tests for ljust/rjust added --- mrbgems/mruby-string-ext/mrblib/string.rb | 46 ---------------- mrbgems/mruby-string-ext/src/string.c | 92 +++++++++++++++++++++++++++++++ mrbgems/mruby-string-ext/test/string.rb | 20 +++++++ 3 files changed, 112 insertions(+), 46 deletions(-) diff --git a/mrbgems/mruby-string-ext/mrblib/string.rb b/mrbgems/mruby-string-ext/mrblib/string.rb index 6e5f3c73d..610a462a7 100644 --- a/mrbgems/mruby-string-ext/mrblib/string.rb +++ b/mrbgems/mruby-string-ext/mrblib/string.rb @@ -263,52 +263,6 @@ class String self end - ## - # call-seq: - # str.ljust(integer, padstr=' ') -> new_str - # - # If integer is greater than the length of str, returns a new - # String of length integer with str left justified - # and padded with padstr; otherwise, returns str. - # - # "hello".ljust(4) #=> "hello" - # "hello".ljust(20) #=> "hello " - # "hello".ljust(20, '1234') #=> "hello123412341234123" - def ljust(idx, padstr = ' ') - if idx <= self.size - return self - end - newstr = self.dup - newstr << padstr - while newstr.size <= idx - newstr << padstr - end - return newstr.slice(0,idx) - end - - ## - # call-seq: - # str.rjust(integer, padstr=' ') -> new_str - # - # If integer is greater than the length of str, returns a new - # String of length integer with str right justified - # and padded with padstr; otherwise, returns str. - # - # "hello".rjust(4) #=> "hello" - # "hello".rjust(20) #=> " hello" - # "hello".rjust(20, '1234') #=> "123412341234123hello" - def rjust(idx, padstr = ' ') - if idx <= self.size - return self - end - padsize = idx - self.size - newstr = padstr.dup - while newstr.size <= padsize - newstr << padstr - end - return newstr.slice(0,padsize) + self - end - # str.upto(other_str, exclusive=false) {|s| block } -> str # str.upto(other_str, exclusive=false) -> an_enumerator # diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c index 7e87b3db4..45d406f6f 100644 --- a/mrbgems/mruby-string-ext/src/string.c +++ b/mrbgems/mruby-string-ext/src/string.c @@ -5,6 +5,9 @@ #include #include +#define MAX(a,b) ((a)>(b) ? (a) : (b)) +#define MIN(a,b) ((a)<(b) ? (a) : (b)) + static mrb_value mrb_str_getbyte(mrb_state *mrb, mrb_value str) { @@ -509,6 +512,93 @@ mrb_str_ord(mrb_state* mrb, mrb_value str) } #endif +static mrb_value +mrb_str_just(mrb_state* mrb, mrb_value str, mrb_bool right_just) +{ + mrb_value new_str; + mrb_int idx = 0, i = 0, bytes_to_copy = 0, start_pos = 0, final_pos = 0, + pad_str_length = 0; + mrb_int str_length = RSTRING_LEN(str); + const char *pad_str = NULL; + char *new_str_ptr = NULL; + + mrb_get_args(mrb, "i|s!", &idx, &pad_str, &pad_str_length); + + if (pad_str == NULL) + { + pad_str = " "; + pad_str_length = 1; + } + + if (pad_str_length == 0) + { + mrb_raise(mrb, E_ARGUMENT_ERROR, "zero width padding"); + } + + if (idx <= str_length) + { + return str; + } + + new_str = mrb_str_dup(mrb, str); + mrb_str_resize(mrb, new_str, idx); + + new_str_ptr = RSTRING_PTR(new_str); + + if (right_just) + { + memcpy(new_str_ptr + idx - str_length, RSTRING_PTR(str), str_length); + } + + start_pos = right_just ? 0 : str_length; + final_pos = idx - (right_just ? str_length : 0); + + for (i = start_pos; i < final_pos; i += pad_str_length) + { + bytes_to_copy = idx - i - (right_just ? str_length : 0); + bytes_to_copy = MIN(pad_str_length, bytes_to_copy); + memcpy(new_str_ptr + i, pad_str, bytes_to_copy); + } + + return new_str; +} + +/* + * call-seq: + * str.ljust(integer, padstr=' ') -> new_str + * + * If integer is greater than the length of str, returns a new + * String of length integer with str left justified + * and padded with padstr; otherwise, returns str. + * + * "hello".ljust(4) #=> "hello" + * "hello".ljust(20) #=> "hello " + * "hello".ljust(20, '1234') #=> "hello123412341234123" + */ +static mrb_value +mrb_str_ljust(mrb_state* mrb, mrb_value str) +{ + return mrb_str_just(mrb, str, FALSE); +} + +/* + * call-seq: + * str.rjust(integer, padstr=' ') -> new_str + * + * If integer is greater than the length of str, returns a new + * String of length integer with str right justified + * and padded with padstr; otherwise, returns str. + * + * "hello".rjust(4) #=> "hello" + * "hello".rjust(20) #=> " hello" + * "hello".rjust(20, '1234') #=> "123412341234123hello" + */ +static mrb_value +mrb_str_rjust(mrb_state* mrb, mrb_value str) +{ + return mrb_str_just(mrb, str, TRUE); +} + void mrb_mruby_string_ext_gem_init(mrb_state* mrb) { @@ -530,6 +620,8 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb) mrb_define_method(mrb, s, "lines", mrb_str_lines, MRB_ARGS_NONE()); mrb_define_method(mrb, s, "succ", mrb_str_succ, MRB_ARGS_NONE()); mrb_define_method(mrb, s, "succ!", mrb_str_succ_bang, MRB_ARGS_NONE()); + mrb_define_method(mrb, s, "ljust", mrb_str_ljust, MRB_ARGS_REQ(1)|MRB_ARGS_OPT(1)); + mrb_define_method(mrb, s, "rjust", mrb_str_rjust, MRB_ARGS_REQ(1)|MRB_ARGS_OPT(1)); mrb_alias_method(mrb, s, mrb_intern_lit(mrb, "next"), mrb_intern_lit(mrb, "succ")); mrb_alias_method(mrb, s, mrb_intern_lit(mrb, "next!"), mrb_intern_lit(mrb, "succ!")); mrb_define_method(mrb, s, "ord", mrb_str_ord, MRB_ARGS_NONE()); diff --git a/mrbgems/mruby-string-ext/test/string.rb b/mrbgems/mruby-string-ext/test/string.rb index 228a236af..2b2c02b8b 100644 --- a/mrbgems/mruby-string-ext/test/string.rb +++ b/mrbgems/mruby-string-ext/test/string.rb @@ -444,6 +444,26 @@ assert('String#rjust') do assert_equal "hello", "hello".rjust(-3) end +assert('String#ljust should not change string') do + a = "hello" + a.ljust(20) + assert_equal "hello", a +end + +assert('String#rjust should not change string') do + a = "hello" + a.rjust(20) + assert_equal "hello", a +end + +assert('String#ljust should raise on zero width padding') do + assert_raise(ArgumentError) { "foo".ljust(10, '') } +end + +assert('String#rjust should raise on zero width padding') do + assert_raise(ArgumentError) { "foo".rjust(10, '') } +end + assert('String#upto') do a = "aa" start = "aa" -- cgit v1.2.3