String#ljust and String#rjust reimplementation (fix
- 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
MODIFY
mrbgems/mruby-string-ext/mrblib/string.rb
mrbgems/mruby-string-ext/mrblib/string.rb
@@ -263,52 +263,6 @@ class String
self
end
- ##
- # call-seq:
- # str.ljust(integer, padstr=' ') -> new_str
- #
- # If <i>integer</i> is greater than the length of <i>str</i>, returns a new
- # <code>String</code> of length <i>integer</i> with <i>str</i> left justified
- # and padded with <i>padstr</i>; otherwise, returns <i>str</i>.
- #
- # "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 <i>integer</i> is greater than the length of <i>str</i>, returns a new
- # <code>String</code> of length <i>integer</i> with <i>str</i> right justified
- # and padded with <i>padstr</i>; otherwise, returns <i>str</i>.
- #
- # "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
#

MODIFY
mrbgems/mruby-string-ext/src/string.c
mrbgems/mruby-string-ext/src/string.c
#include <mruby/string.h>
#include <mruby/range.h>
+#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 <i>integer</i> is greater than the length of <i>str</i>, returns a new
+ * <code>String</code> of length <i>integer</i> with <i>str</i> left justified
+ * and padded with <i>padstr</i>; otherwise, returns <i>str</i>.
+ *
+ * "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 <i>integer</i> is greater than the length of <i>str</i>, returns a new
+ * <code>String</code> of length <i>integer</i> with <i>str</i> right justified
+ * and padded with <i>padstr</i>; otherwise, returns <i>str</i>.
+ *
+ * "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());

MODIFY
mrbgems/mruby-string-ext/test/string.rb
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"

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