Files
mruby-mruby/mrbgems/mruby-rational
Yukihiro "Matz" Matsumoto a9825e92df mruby-rational: fix crash in rational_new_f with negative exponent
rational_new_b() expects both arguments to be bigints, but rational_new_f()
was passing an integer value for the numerator when the exponent was negative.
This caused a segfault in mrb_bint_reduce() which called RBIGINT() on the
integer value.

Test case: 5r**-92 (from oss-fuzz)

Co-authored-by: Claude <noreply@anthropic.com>
2026-01-03 13:13:02 +09:00
..
2025-01-26 21:11:21 +09:00
2025-06-17 16:22:19 +09:00

mruby-rational

This mrbgem provides a Rational class for mruby, allowing you to work with rational numbers (fractions).

Usage

To use the Rational class, you first need to include the mrbgem in your mruby build.

Include in build_config.rb

Add the following line to your build_config.rb file:

conf.gem :core => 'mruby-rational'

Creating Rational Objects

You can create Rational objects using the Rational() method:

r1 = Rational(1, 2)  # Represents 1/2
r2 = Rational(3, 4)  # Represents 3/4

Arithmetic Operations

The Rational class supports standard arithmetic operations:

r_add = Rational(1, 2) + Rational(1, 3)  # (5/6)
r_sub = Rational(1, 2) - Rational(1, 3)  # (1/6)
r_mul = Rational(1, 2) * Rational(1, 3)  # (1/6)
r_div = Rational(1, 2) / Rational(1, 3)  # (3/2)

Available Methods

The Rational class provides the following important methods:

  • numerator: Returns the numerator of the rational number.
  • denominator: Returns the denominator of the rational number.
  • to_f: Converts the rational number to a Float.
  • to_i: Converts the rational number to an Integer (truncates towards zero).
  • to_s: Returns a string representation of the rational number (e.g., "1/2").
  • inspect: Returns a string representation suitable for debugging (e.g., "(1/2)").
  • ==: Checks for equality with another number.
  • <=>: Compares the rational number with another number.
  • positive?: Returns true if the rational number is greater than zero.
  • negative?: Returns true if the rational number is less than zero.

Error Handling

The mrbgem handles common errors such as:

  • DivisionByZeroError: Raised when attempting to create a rational number with a denominator of zero.
  • RangeError: Raised in case of integer overflow during calculations.

License

mruby-rational is licensed under the MIT License. See LICENSE for details.