Implement `String#upto` in Ruby.
Avoid using `mrb_yield` in C code. The function is not recommended.
Because it doesn't work well with fibers.
MODIFY
mrbgems/mruby-string-ext/mrblib/string.rb
mrbgems/mruby-string-ext/mrblib/string.rb
@@ -386,4 +386,77 @@ class String
end
lines
end
+
+ ##
+ # call-seq:
+ # str.upto(other_str, exclusive=false) {|s| block } -> str
+ # str.upto(other_str, exclusive=false) -> an_enumerator
+ #
+ # Iterates through successive values, starting at <i>str</i> and
+ # ending at <i>other_str</i> inclusive, passing each value in turn to
+ # the block. The <code>String#succ</code> method is used to generate
+ # each value. If optional second argument exclusive is omitted or is false,
+ # the last value will be included; otherwise it will be excluded.
+ #
+ # If no block is given, an enumerator is returned instead.
+ #
+ # "a8".upto("b6") {|s| print s, ' ' }
+ # for s in "a8".."b6"
+ # print s, ' '
+ # end
+ #
+ # <em>produces:</em>
+ #
+ # a8 a9 b0 b1 b2 b3 b4 b5 b6
+ # a8 a9 b0 b1 b2 b3 b4 b5 b6
+ #
+ # If <i>str</i> and <i>other_str</i> contains only ascii numeric characters,
+ # both are recognized as decimal numbers. In addition, the width of
+ # string (e.g. leading zeros) is handled appropriately.
+ #
+ # "9".upto("11").to_a #=> ["9", "10", "11"]
+ # "25".upto("5").to_a #=> []
+ # "07".upto("11").to_a #=> ["07", "08", "09", "10", "11"]
+ def upto(max, exclusive=false, &block)
+ return to_enum(:upto, max, exclusive) unless block
+ raise TypeError, "no implicit conversion of #{max.class} into String" unless max.kind_of? String
+
+ len = self.length
+ maxlen = max.length
+ # single character
+ if len == 1 and maxlen == 1
+ c = self.ord
+ e = max.ord
+ while c <= e
+ break if exclusive and c == e
+ yield c.chr
+ c += 1
+ end
+ return self
+ end
+ # both edges are all digits
+ bi = self.to_i(10)
+ ei = max.to_i(10)
+ len = self.length
+ if (bi > 0 or bi == "0"*len) and (ei > 0 or ei == "0"*maxlen)
+ while bi <= ei
+ break if exclusive and bi == ei
+ s = bi.to_s
+ s = s.rjust(len, "0") if s.length < len
+ yield s
+ bi += 1
+ end
+ return self
+ end
+ bs = self
+ while true
+ n = (bs <=> max)
+ break if n > 0
+ break if exclusive and n == 0
+ yield bs
+ break if n == 0
+ bs = bs.succ
+ end
+ self
+ end
end

MODIFY
mrbgems/mruby-string-ext/src/string.c
mrbgems/mruby-string-ext/src/string.c
@@ -470,135 +470,6 @@ mrb_str_ord(mrb_state* mrb, mrb_value str)
}
#endif
-static mrb_bool
-all_digits_p(const char *s, mrb_int len)
-{
- while (len-- > 0) {
- if (!ISDIGIT(*s)) return FALSE;
- s++;
- }
- return TRUE;
-}
-
-/*
- * call-seq:
- * str.upto(other_str, exclusive=false) {|s| block } -> str
- * str.upto(other_str, exclusive=false) -> an_enumerator
- *
- * Iterates through successive values, starting at <i>str</i> and
- * ending at <i>other_str</i> inclusive, passing each value in turn to
- * the block. The <code>String#succ</code> method is used to generate
- * each value. If optional second argument exclusive is omitted or is false,
- * the last value will be included; otherwise it will be excluded.
- *
- * If no block is given, an enumerator is returned instead.
- *
- * "a8".upto("b6") {|s| print s, ' ' }
- * for s in "a8".."b6"
- * print s, ' '
- * end
- *
- * <em>produces:</em>
- *
- * a8 a9 b0 b1 b2 b3 b4 b5 b6
- * a8 a9 b0 b1 b2 b3 b4 b5 b6
- *
- * If <i>str</i> and <i>other_str</i> contains only ascii numeric characters,
- * both are recognized as decimal numbers. In addition, the width of
- * string (e.g. leading zeros) is handled appropriately.
- *
- * "9".upto("11").to_a #=> ["9", "10", "11"]
- * "25".upto("5").to_a #=> []
- * "07".upto("11").to_a #=> ["07", "08", "09", "10", "11"]
- */
-static mrb_value
-mrb_str_upto(mrb_state *mrb, mrb_value beg)
-{
- mrb_value end;
- mrb_value exclusive = mrb_false_value();
- mrb_value block = mrb_nil_value();
- mrb_value current, after_end;
- mrb_int n;
- mrb_bool excl;
-
- mrb_get_args(mrb, "o|o&", &end, &exclusive, &block);
-
- if (mrb_nil_p(block)) {
- return mrb_funcall(mrb, beg, "to_enum", 3, mrb_symbol_value(mrb_intern_lit(mrb, "upto")), end, exclusive);
- }
- end = mrb_string_type(mrb, end);
- excl = mrb_test(exclusive);
-
- /* single character */
- if (RSTRING_LEN(beg) == 1 && RSTRING_LEN(end) == 1 &&
- ISASCII(RSTRING_PTR(beg)[0]) && ISASCII(RSTRING_PTR(end)[0])) {
- char c = RSTRING_PTR(beg)[0];
- char e = RSTRING_PTR(end)[0];
- int ai = mrb_gc_arena_save(mrb);
-
- if (c > e || (excl && c == e)) return beg;
- for (;;) {
- mrb_yield(mrb, block, mrb_str_new(mrb, &c, 1));
- mrb_gc_arena_restore(mrb, ai);
- if (!excl && c == e) break;
- c++;
- if (excl && c == e) break;
- }
- return beg;
- }
- /* both edges are all digits */
- if (ISDIGIT(RSTRING_PTR(beg)[0]) && ISDIGIT(RSTRING_PTR(end)[0]) &&
- all_digits_p(RSTRING_PTR(beg), RSTRING_LEN(beg)) &&
- all_digits_p(RSTRING_PTR(end), RSTRING_LEN(end))) {
- mrb_int min_width = RSTRING_LEN(beg);
- mrb_int bi = mrb_int(mrb, mrb_str_to_inum(mrb, beg, 10, FALSE));
- mrb_int ei = mrb_int(mrb, mrb_str_to_inum(mrb, end, 10, FALSE));
- int ai = mrb_gc_arena_save(mrb);
-
- while (bi <= ei) {
- mrb_value ns, str;
-
- if (excl && bi == ei) break;
- ns = mrb_format(mrb, "%S", mrb_fixnum_value(bi));
- if (min_width > RSTRING_LEN(ns)) {
- str = mrb_str_new(mrb, NULL, min_width);
- memset(RSTRING_PTR(str), '0', min_width-RSTRING_LEN(ns));
- memcpy(RSTRING_PTR(str)+min_width-RSTRING_LEN(ns),
- RSTRING_PTR(ns), RSTRING_LEN(ns));
- }
- else {
- str = ns;
- }
- mrb_yield(mrb, block, str);
- mrb_gc_arena_restore(mrb, ai);
- bi++;
- }
-
- return beg;
- }
- /* normal case */
- n = mrb_int(mrb, mrb_funcall(mrb, beg, "<=>", 1, end));
- if (n > 0 || (excl && n == 0)) return beg;
-
- after_end = mrb_funcall(mrb, end, "succ", 0);
- current = mrb_str_dup(mrb, beg);
- while (!mrb_str_equal(mrb, current, after_end)) {
- int ai = mrb_gc_arena_save(mrb);
- mrb_value next = mrb_nil_value();
- if (excl || !mrb_str_equal(mrb, current, end))
- next = mrb_funcall(mrb, current, "succ", 0);
- mrb_yield(mrb, block, current);
- if (mrb_nil_p(next)) break;
- current = mrb_str_to_str(mrb, next);
- if (excl && mrb_str_equal(mrb, current, end)) break;
- if (RSTRING_LEN(current) > RSTRING_LEN(end) || RSTRING_LEN(current) == 0)
- break;
- mrb_gc_arena_restore(mrb, ai);
- }
-
- return beg;
-}
-
/*
* call-seq:
* str.delete_prefix!(prefix) -> self or nil
@@ -759,7 +630,6 @@ mrb_mruby_string_ext_gem_init(mrb_state* mrb)
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());
- mrb_define_method(mrb, s, "upto", mrb_str_upto, MRB_ARGS_ANY());
mrb_define_method(mrb, s, "delete_prefix!", mrb_str_del_prefix_bang, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "delete_prefix", mrb_str_del_prefix, MRB_ARGS_REQ(1));
mrb_define_method(mrb, s, "delete_suffix!", mrb_str_del_suffix_bang, MRB_ARGS_REQ(1));

Implement `String#upto` in Ruby.

Avoid using `mrb_yield` in C code. The function is not recommended.
Because it doesn't work well with fibers.