Crate weird_data

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.
• i8
  Generate a random i8 , such that special or problematic values are much more common than normal.
• i16
  Generate a random i16 , such that special or problematic values are much more common than normal.
• i32
  Generate a random i32 , such that special or problematic values are much more common than normal.
• i64
  Generate a random i64 , such that special or problematic values are much more common than normal.
• i128
  Generate a random i128 , such that special or problematic values are much more common than normal.
• isize
  Generate a random isize , such that special or problematic values are much more common than normal.
• 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
• special_i8
  Generate a random i8 “special” value
• special_i16
  Generate a random i16 “special” value
• special_i32
  Generate a random i32 “special” value
• special_i64
  Generate a random i64 “special” value
• special_i128
  Generate a random i128 “special” value
• special_isize
  Generate a random isize “special” value
• special_u8
  Generate a random u8 “special” value
• special_u16
  Generate a random u16 “special” value
• special_u32
  Generate a random u32 “special” value
• special_u64
  Generate a random u64 “special” value
• special_u128
  Generate a random u128 “special” value
• special_usize
  Generate a random usize “special” value
• subnormal_f32
  Generates a random f32 denormal value.
• subnormal_f64
  Generates a random f64 denormal value.
• u8
  Generate a random u8 , such that special or problematic values are much more common than normal.
• u16
  Generate a random u16 , such that special or problematic values are much more common than normal.
• u32
  Generate a random u32 , such that special or problematic values are much more common than normal.
• u64
  Generate a random u64 , such that special or problematic values are much more common than normal.
• u128
  Generate a random u128 , such that special or problematic values are much more common than normal.
• usize
  Generate a random usize , such that special or problematic values are much more common than normal.