3 files changed, 181 insertions, 10 deletions

diff --git a/mrbgems/mruby-string-ext/mrblib/string.rb b/mrbgems/mruby-string-ext/mrblib/string.rb
index 45c631b94..1cfb7e2f5 100644
--- a/mrbgems/mruby-string-ext/mrblib/string.rb
+++ b/mrbgems/mruby-string-ext/mrblib/string.rb
@@ -1,4 +1,28 @@
 class String
+
+  ##
+  # call-seq:
+  #    string.clear    ->  string
+  #
+  # Makes string empty.
+  #
+  #    a = "abcde"
+  #    a.clear    #=> ""
+  #
+  def clear
+    self.replace("")
+  end
+
+  ##
+  # call-seq:
+  #    str.lstrip   -> new_str
+  #
+  # Returns a copy of <i>str</i> with leading whitespace removed. See also
+  # <code>String#rstrip</code> and <code>String#strip</code>.
+  #
+  #    "  hello  ".lstrip   #=> "hello  "
+  #    "hello".lstrip       #=> "hello"
+  #
   def lstrip
     a = 0
     z = self.size - 1
@@ -6,6 +30,16 @@ class String
     (z >= 0) ? self[a..z] : ""
   end
 
+  ##
+  # call-seq:
+  #    str.rstrip   -> new_str
+  #
+  # Returns a copy of <i>str</i> with trailing whitespace removed. See also
+  # <code>String#lstrip</code> and <code>String#strip</code>.
+  #
+  #    "  hello  ".rstrip   #=> "  hello"
+  #    "hello".rstrip       #=> "hello"
+  #
   def rstrip
     a = 0
     z = self.size - 1
@@ -13,6 +47,15 @@ class String
     (z >= 0) ? self[a..z] : ""
   end
 
+  ##
+  # call-seq:
+  #    str.strip   -> new_str
+  #
+  # Returns a copy of <i>str</i> with leading and trailing whitespace removed.
+  #
+  #    "    hello    ".strip   #=> "hello"
+  #    "\tgoodbye\r\n".strip   #=> "goodbye"
+  #
   def strip
     a = 0
     z = self.size - 1
@@ -21,31 +64,61 @@ class String
     (z >= 0) ? self[a..z] : ""
   end
 
+  ##
+  # call-seq:
+  #    str.lstrip!   -> self or nil
+  #
+  # Removes leading whitespace from <i>str</i>, returning <code>nil</code> if no
+  # change was made. See also <code>String#rstrip!</code> and
+  # <code>String#strip!</code>.
+  #
+  #    "  hello  ".lstrip   #=> "hello  "
+  #    "hello".lstrip!      #=> nil
+  #
   def lstrip!
     s = self.lstrip
     (s == self) ? nil : self.replace(s)
   end
 
+  ##
+  # call-seq:
+  #    str.rstrip!   -> self or nil
+  #
+  # Removes trailing whitespace from <i>str</i>, returning <code>nil</code> if
+  # no change was made. See also <code>String#lstrip!</code> and
+  # <code>String#strip!</code>.
+  #
+  #    "  hello  ".rstrip   #=> "  hello"
+  #    "hello".rstrip!      #=> nil
+  #
   def rstrip!
     s = self.rstrip
     (s == self) ? nil : self.replace(s)
   end
 
+  ##
+  #  call-seq:
+  #     str.strip!   -> str or nil
+  #
+  #  Removes leading and trailing whitespace from <i>str</i>. Returns
+  #  <code>nil</code> if <i>str</i> was not altered.
+  #
   def strip!
     s = self.strip
     (s == self) ? nil : self.replace(s)
   end
 
-# call-seq:
-#    str.casecmp(other_str)   -> -1, 0, +1 or nil
-#
-# Case-insensitive version of <code>String#<=></code>.
-#
-#    "abcdef".casecmp("abcde")     #=> 1
-#    "aBcDeF".casecmp("abcdef")    #=> 0
-#    "abcdef".casecmp("abcdefg")   #=> -1
-#    "abcdef".casecmp("ABCDEF")    #=> 0
-#
+  ##
+  # call-seq:
+  #    str.casecmp(other_str)   -> -1, 0, +1 or nil
+  #
+  # Case-insensitive version of <code>String#<=></code>.
+  #
+  #    "abcdef".casecmp("abcde")     #=> 1
+  #    "aBcDeF".casecmp("abcdef")    #=> 0
+  #    "abcdef".casecmp("abcdefg")   #=> -1
+  #    "abcdef".casecmp("ABCDEF")    #=> 0
+  #
   def casecmp(str)
     self.downcase <=> str.to_str.downcase
   rescue NoMethodError
diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c
index 2c0a406ad..f04f12c4b 100644
--- a/mrbgems/mruby-string-ext/src/string.c
+++ b/mrbgems/mruby-string-ext/src/string.c
@@ -1,6 +1,8 @@
 #include <ctype.h>
 #include <string.h>
 #include "mruby.h"
+#include "mruby/array.h"
+#include "mruby/class.h"
 #include "mruby/string.h"
 
 static mrb_value
@@ -175,6 +177,68 @@ mrb_str_oct(mrb_state *mrb, mrb_value self)
   return mrb_str_to_inum(mrb, self, 8, FALSE);
 }
 
+/*
+ *  call-seq:
+ *     string.chr    ->  string
+ *
+ *  Returns a one-character string at the beginning of the string.
+ *
+ *     a = "abcde"
+ *     a.chr    #=> "a"
+ */
+static mrb_value
+mrb_str_chr(mrb_state *mrb, mrb_value self)
+{
+  return mrb_str_substr(mrb, self, 0, 1);
+}
+
+/*
+ *  call-seq:
+ *     string.lines    ->  array of string
+ *
+ *  Returns strings per line;
+ *
+ *     a = "abc\ndef"
+ *     a.lines    #=> ["abc\n", "def"]
+ */
+static mrb_value
+mrb_str_lines(mrb_state *mrb, mrb_value self)
+{
+  mrb_value result;
+  mrb_value blk;
+  int ai;
+  mrb_int len;
+  mrb_value arg;
+  char *p = RSTRING_PTR(self), *t;
+  char *e = p + RSTRING_LEN(self);
+
+  mrb_get_args(mrb, "&", &blk);
+
+  result = mrb_ary_new(mrb);
+
+  if (!mrb_nil_p(blk)) {
+    while (p < e) {
+      t = p;
+      while (p < e && *p != '\n') p++;
+      if (*p == '\n') p++;
+      len = (mrb_int) (p - t);
+      arg = mrb_str_new(mrb, t, len);
+      mrb_yield_argv(mrb, blk, 1, &arg);
+    }
+    return self;
+  }
+  while (p < e) {
+    ai = mrb_gc_arena_save(mrb);
+    t = p;
+    while (p < e && *p != '\n') p++;
+    if (*p == '\n') p++;
+    len = (mrb_int) (p - t);
+    mrb_ary_push(mrb, result, mrb_str_new(mrb, t, len));
+    mrb_gc_arena_restore(mrb, ai);
+  }
+  return result;
+}
+
 void
 mrb_mruby_string_ext_gem_init(mrb_state* mrb)
 {
@@ -190,6 +254,8 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb)
   mrb_define_method(mrb, s, "end_with?",       mrb_str_end_with,        MRB_ARGS_REST());
   mrb_define_method(mrb, s, "hex",             mrb_str_hex,             MRB_ARGS_NONE());
   mrb_define_method(mrb, s, "oct",             mrb_str_oct,             MRB_ARGS_NONE());
+  mrb_define_method(mrb, s, "chr",             mrb_str_chr,             MRB_ARGS_NONE());
+  mrb_define_method(mrb, s, "lines",           mrb_str_lines,           MRB_ARGS_NONE());
 }
 
 void
diff --git a/mrbgems/mruby-string-ext/test/string.rb b/mrbgems/mruby-string-ext/test/string.rb
index 01712a607..72c919b35 100644
--- a/mrbgems/mruby-string-ext/test/string.rb
+++ b/mrbgems/mruby-string-ext/test/string.rb
@@ -161,3 +161,35 @@ assert('String#oct') do
   assert_equal 8, "010".oct
   assert_equal (-8), "-10".oct
 end
+
+assert('String#chr') do
+  assert_equal "a", "abcde".chr
+end
+
+assert('String#lines') do
+  assert_equal ["Hel\n", "lo\n", "World!"], "Hel\nlo\nWorld!".lines
+  assert_equal ["Hel\n", "lo\n", "World!\n"], "Hel\nlo\nWorld!\n".lines
+  assert_equal ["\n", "\n", "\n"], "\n\n\n".lines
+  assert_equal [], "".lines
+end
+
+assert('String#clear') do
+  # embed string
+  s = "foo"
+  assert_equal("", s.clear)
+  assert_equal("", s)
+
+  # not embed string and not shared string
+  s = "foo" * 100
+  a = s
+  assert_equal("", s.clear)
+  assert_equal("", s)
+  assert_equal("", a)
+
+  # shared string
+  s = "foo" * 100
+  a = s[10, 90]                # create shared string
+  assert_equal("", s.clear)    # clear
+  assert_equal("", s)          # s is cleared
+  assert_not_equal("", a)      # a should not be affected
+end