mirror of
https://github.com/mruby/mruby
synced 2026-06-08 16:11:16 +00:00
Yukihiro "Matz" Matsumoto
5eca2fae1e
In rational_new_f(), the code performed ((mrb_int)1)<<exp without checking if exp >= MRB_INT_BIT. Shifting by a value >= bit width is undefined behavior in C. Also fixed the negative exponent case which incorrectly used deno >>= exp (right-shift by negative is UB). The correct logic is deno <<= -exp to multiply denominator by 2^(-exp). Both cases now check for overflow before shifting and fall back to bigint operations when necessary. Discovered via ClusterFuzz with input "92r**11". Co-authored-by: Claude <noreply@anthropic.com>
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 aFloat.to_i: Converts the rational number to anInteger(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?: Returnstrueif the rational number is greater than zero.negative?: Returnstrueif 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.