diff --git a/ext/strscan/strscan.c b/ext/strscan/strscan.c
index d4135e4baf..54843dbcc5 100644
--- a/ext/strscan/strscan.c
+++ b/ext/strscan/strscan.c
@@ -1852,6 +1852,80 @@ strscan_values_at(int argc, VALUE *argv, VALUE self)
return new_ary;
}
+/*
+ * call-seq:
+ * integer_at(index) -> integer or nil
+ *
+ * Returns the captured substring at the given +index+ as an Integer,
+ * without creating an intermediate String object.
+ *
+ * Returns +nil+ if the most recent match failed, or if the capture
+ * at +index+ is out of range, or if the capture did not participate
+ * in the match.
+ *
+ * This is semantically equivalent to self[index].to_i but
+ * avoids the allocation of a temporary String.
+ *
+ * scanner = StringScanner.new("2024-06-15")
+ * scanner.scan(/(\d{4})-(\d{2})-(\d{2})/)
+ * scanner.integer_at(1) # => 2024
+ * scanner.integer_at(2) # => 6
+ * scanner.integer_at(3) # => 15
+ * scanner.integer_at(0) # => 20240615 (entire match as integer)
+ *
+ */
+/* rb_int_parse_cstr is declared in internal/bignum.h which is not
+ * available to extensions. Declare it here since the symbol is
+ * exported from libruby. */
+VALUE rb_int_parse_cstr(const char *str, ssize_t len, char **endp,
+ size_t *ndigits, int base, int flags);
+#define RB_INT_PARSE_SIGN 0x01
+
+static VALUE
+strscan_integer_at(VALUE self, VALUE idx)
+{
+ struct strscanner *p;
+ long i;
+ long beg, end, len;
+ const char *ptr;
+
+ GET_SCANNER(self, p);
+ if (! MATCHED_P(p)) return Qnil;
+
+ i = NUM2LONG(idx);
+
+ if (i < 0)
+ i += p->regs.num_regs;
+ if (i < 0) return Qnil;
+ if (i >= p->regs.num_regs) return Qnil;
+ if (p->regs.beg[i] == -1) return Qnil;
+
+ beg = adjust_register_position(p, p->regs.beg[i]);
+ end = adjust_register_position(p, p->regs.end[i]);
+ len = end - beg;
+
+ if (len <= 0) {
+ rb_raise(rb_eArgError, "empty capture for integer conversion");
+ }
+
+ ptr = S_PBEG(p) + beg;
+
+ /* Parse directly from source bytes without buffer allocation.
+ * rb_int_parse_cstr accepts a length so no NUL-termination needed.
+ * Use endp to verify the entire capture was consumed as digits. */
+ {
+ char *endp;
+ VALUE integer = rb_int_parse_cstr(ptr, len, &endp, NULL, 10, RB_INT_PARSE_SIGN);
+
+ if (endp != ptr + len) {
+ rb_raise(rb_eArgError,
+ "non-digit character in capture: %.*s",
+ (int)len, ptr);
+ }
+ return integer;
+ }
+}
+
/*
* :markup: markdown
* :include: strscan/link_refs.txt
@@ -2290,6 +2364,7 @@ Init_strscan(void)
rb_define_method(StringScanner, "size", strscan_size, 0);
rb_define_method(StringScanner, "captures", strscan_captures, 0);
rb_define_method(StringScanner, "values_at", strscan_values_at, -1);
+ rb_define_method(StringScanner, "integer_at", strscan_integer_at, 1);
rb_define_method(StringScanner, "rest", strscan_rest, 0);
rb_define_method(StringScanner, "rest_size", strscan_rest_size, 0);
diff --git a/test/strscan/test_stringscanner.rb b/test/strscan/test_stringscanner.rb
index dd3663ea6a..a3f32aac1c 100644
--- a/test/strscan/test_stringscanner.rb
+++ b/test/strscan/test_stringscanner.rb
@@ -968,6 +968,112 @@ def test_named_captures_same_name_union
assert_equal({"number" => "1"}, scan.named_captures)
end
+ def test_integer_at
+ s = create_string_scanner("2024-06-15")
+ s.scan(/(\d{4})-(\d{2})-(\d{2})/)
+ assert_equal(2024, s.integer_at(1))
+ assert_equal(6, s.integer_at(2))
+ assert_equal(15, s.integer_at(3))
+ end
+
+ def test_integer_at_index_zero
+ s = create_string_scanner("42 abc")
+ s.scan(/(\d+)/)
+ assert_equal(42, s.integer_at(0))
+ end
+
+ def test_integer_at_negative_index
+ s = create_string_scanner("2024-06-15")
+ s.scan(/(\d{4})-(\d{2})-(\d{2})/)
+ assert_equal(15, s.integer_at(-1))
+ assert_equal(6, s.integer_at(-2))
+ assert_equal(2024, s.integer_at(-3))
+ end
+
+ def test_integer_at_no_match
+ s = create_string_scanner("abc")
+ s.scan(/\d+/)
+ assert_nil(s.integer_at(0))
+ end
+
+ def test_integer_at_before_match
+ s = create_string_scanner("abc")
+ assert_nil(s.integer_at(0))
+ end
+
+ def test_integer_at_index_out_of_range
+ s = create_string_scanner("42")
+ s.scan(/(\d+)/)
+ assert_nil(s.integer_at(2))
+ assert_nil(s.integer_at(100))
+ assert_nil(s.integer_at(-3))
+ end
+
+ def test_integer_at_optional_group_not_matched
+ s = create_string_scanner("2024-06")
+ s.scan(/(\d{4})-(\d{2})(-(\d{2}))?/)
+ assert_equal(2024, s.integer_at(1))
+ assert_equal(6, s.integer_at(2))
+ assert_nil(s.integer_at(4))
+ end
+
+ def test_integer_at_large_number
+ huge = '9' * 100
+ s = create_string_scanner(huge)
+ s.scan(/(#{huge})/)
+ assert_equal(huge.to_i, s.integer_at(1))
+ end
+
+ def test_integer_at_non_digit
+ s = create_string_scanner("1.5")
+ s.scan(/([\d.]+)/)
+ assert_raise(ArgumentError) { s.integer_at(1) }
+ end
+
+ def test_integer_at_non_digit_alpha
+ s = create_string_scanner("foo bar")
+ s.scan(/(\w+)/)
+ assert_raise(ArgumentError) { s.integer_at(1) }
+ end
+
+ def test_integer_at_empty_capture
+ s = create_string_scanner("abc")
+ s.scan(/()abc/)
+ assert_raise(ArgumentError) { s.integer_at(1) }
+ end
+
+ def test_integer_at_sign_only
+ s = create_string_scanner("+")
+ s.scan(/([+\-])/)
+ assert_raise(ArgumentError) { s.integer_at(1) }
+
+ s = create_string_scanner("-")
+ s.scan(/([+\-])/)
+ assert_raise(ArgumentError) { s.integer_at(1) }
+ end
+
+ def test_integer_at_signed_number
+ s = create_string_scanner("-42")
+ s.scan(/([+\-]?\d+)/)
+ assert_equal(-42, s.integer_at(1))
+
+ s = create_string_scanner("+42")
+ s.scan(/([+\-]?\d+)/)
+ assert_equal(42, s.integer_at(1))
+ end
+
+ def test_integer_at_leading_zeros
+ s = create_string_scanner("007")
+ s.scan(/(\d+)/)
+ assert_equal(7, s.integer_at(1))
+ end
+
+ def test_integer_at_full_match_with_non_digits
+ s = create_string_scanner("2024-06-15")
+ s.scan(/(\d{4})-(\d{2})-(\d{2})/)
+ assert_raise(ArgumentError) { s.integer_at(0) }
+ end
+
def test_scan_integer
s = create_string_scanner('abc')
assert_equal(3, s.match?(/(?abc)/)) # set named_captures