Crate weird_data

source ·
Expand description

Generate random data in such a way as to make rare edge-cases very likely.

Disclaimer: the random number generators used in this crate are NOT CRYPTOGRAPHICALLY SECURE. Only use these generators for generating testing inputs, do not rely on them for cryptographic purposes in production code! For instance, you may test a cryptographic tool with these generators, but you may not deploy code that relies on these generators for security in production.

For instance, if generating a random f32 by uniformly sampling 32 bits of data, certain values will rarely appear, such as NAN and INFINITY. When doing randomized testing, like fuzzing, it isn’t very useful to repeatedly generate well-behaved data. It is much more useful if we can artificially increase the likelihood of these special values, so that we test with them more often.

Additionally, some random number crates will never generate certain problematic bit-patterns, such as NAN.

This crate is based on the fastrand crate.

This crate can work with no_std, if you disable the std feature. You cannot use the global functions when in a no_std environment. In that case, you can explicitly instantiate Wdg and call the methods on it. They are equivalent.

If using std, it’s more ergonomic to use the global functions in the [global_functions] module.

Structs

  • Wdg
    A weird data generator

Functions

  • f32
    Generate a random f32, such that special or problematic values are much more common than normal.
  • f64
    Generate a random f64, such that special or problematic values are much more common than normal.
  • get_seed
    Gives back the current seed that is being held by the thread-local generator.
  • nan_f32
    There are multiple bit patterns that are equivalent to a NAN. This generator covers all possible NAN values as specified in IEEE-754, even ones that Rust would normally not generate.
  • nan_f64
    Generates a random f64 NAN value.
  • normal_f32
    Generate a random f32 normal value
  • normal_f64
    Generate a random f64 normal value
  • seed
    Initialize the thread-local generator with the given seed.
  • special_f32
    Generate a random f32 “special” value
  • special_f64
    Generate a random f64 “special” value
  • subnormal_f32
    Generates a random f32 denormal value.
  • subnormal_f64
    Generates a random f64 denormal value.