diff options
| -rw-r--r-- | mrbgems/mruby-string-ext/src/string.c | 39 | ||||
| -rw-r--r-- | mrbgems/mruby-string-ext/test/string.rb | 6 |
2 files changed, 45 insertions, 0 deletions
diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c index 9db3589c7..fa2c52d67 100644 --- a/mrbgems/mruby-string-ext/src/string.c +++ b/mrbgems/mruby-string-ext/src/string.c @@ -331,6 +331,44 @@ mrb_str_succ(mrb_state *mrb, mrb_value self) return str; } +/* + * call-seq: + * str.prepend(other_str) -> str + * + * Prepend---Prepend the given string to <i>str</i>. + * + * a = "world" + * a.prepend("hello ") #=> "hello world" + * a #=> "hello world" + */ +static mrb_value +mrb_str_prepend(mrb_state *mrb, mrb_value self) +{ + struct RString *s1 = mrb_str_ptr(self), *s2, *temp_s; + mrb_int len; + mrb_value other, temp_str; + + mrb_get_args(mrb, "S", &other); + + mrb_str_modify(mrb, s1); + if (!mrb_string_p(other)) { + other = mrb_str_to_str(mrb, other); + } + s2 = mrb_str_ptr(other); + len = RSTR_LEN(s1) + RSTR_LEN(s2); + temp_str = mrb_str_new(mrb, "", RSTR_LEN(s1)); + temp_s = mrb_str_ptr(temp_str); + memcpy(RSTR_PTR(temp_s), RSTR_PTR(s1), RSTR_LEN(s1)); + if (RSTRING_CAPA(self) < len) { + mrb_str_resize(mrb, self, len); + } + memcpy(RSTR_PTR(s1), RSTR_PTR(s2), RSTR_LEN(s2)); + memcpy(RSTR_PTR(s1) + RSTR_LEN(s2), RSTR_PTR(temp_s), RSTR_LEN(temp_s)); + RSTR_SET_LEN(s1, len); + RSTR_PTR(s1)[len] = '\0'; + return self; +} + void mrb_mruby_string_ext_gem_init(mrb_state* mrb) { @@ -350,6 +388,7 @@ 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, "prepend", mrb_str_prepend, MRB_ARGS_REQ(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!")); } diff --git a/mrbgems/mruby-string-ext/test/string.rb b/mrbgems/mruby-string-ext/test/string.rb index 940ffb351..9fa835249 100644 --- a/mrbgems/mruby-string-ext/test/string.rb +++ b/mrbgems/mruby-string-ext/test/string.rb @@ -380,3 +380,9 @@ assert('String#insert') do assert_raise(IndexError) { "abcd".insert(5, 'X') } assert_raise(IndexError) { "abcd".insert(-6, 'X') } end + +assert('String#prepend') do + a = "world" + assert_equal "hello world", a.prepend("hello ") + assert_equal "hello world", a +end |