Crate malachite_base

source ·
Expand description

This crate contains many utilities that are used by the malachite-nz and malachite-q crates. These utilities include

  • Traits that wrap functions from the standard library, like CheckedAdd.
  • Traits that give extra functionality to primitive types, like Gcd, FloorSqrt, and BitAccess.
  • Iterator-producing functions that let you generate values for testing. Here’s an example of an iterator that produces all pairs of u32s:
    use malachite_base::num::exhaustive::exhaustive_unsigneds;
    use malachite_base::tuples::exhaustive::exhaustive_pairs_from_single;
    let mut pairs = exhaustive_pairs_from_single(exhaustive_unsigneds::<u32>());
            (0, 0), (0, 1), (1, 0), (1, 1), (0, 2), (0, 3), (1, 2), (1, 3), (2, 0), (2, 1),
            (3, 0), (3, 1), (2, 2), (2, 3), (3, 2), (3, 3), (0, 4), (0, 5), (1, 4), (1, 5)
  • The RoundingMode enum, which allows you to specify the rounding behavior of various functions.
  • The NiceFloat wrapper, which provides alternative implementations of Eq, Ord, and Display for floating-point values which are in some ways nicer than the defaults.

§Demos and benchmarks

This crate comes with a bin target that can be used for running demos and benchmarks.

  • Almost all of the public functions in this crate have an associated demo. Running a demo shows you a function’s behavior on a large number of inputs. For example, to demo the mod_pow function on u32s, you can use the following command:
    cargo run --features bin_build --release -- -l 10000 -m exhaustive -d demo_mod_pow_u32
    This command uses the exhaustive mode, which generates every possible input, generally starting with the simplest input and progressing to more complex ones. Another mode is random. The -l flag specifies how many inputs should be generated.
  • You can use a similar command to run benchmarks. The following command benchmarks various GCD algorithms for u64s:
    cargo run --features bin_build --release -- -l 1000000 -m random -b \
        benchmark_gcd_algorithms_u64 -o
    This creates a file called You can use gnuplot to create an SVG from it like so:
    gnuplot -e "set terminal svg; l \"\"" > gcd-bench.svg

The list of available demos and benchmarks is not documented anywhere; you must find them by browsing through bin_util/demo_and_bench.


  • test_build: A large proportion of the code in this crate is only used for testing. For a typical user, building this code would result in an unnecessarily long compilation time and an unnecessarily large binary. Much of it is also used for testing malachite-nz and malachite-q, so it can’t just be confined to the tests directory. My solution is to only build this code when the test_build feature is enabled. If you want to run unit tests, you must enable test_build. However, doctests don’t require it, since they only test the public interface.
  • bin_build: This feature is used to build the code for demos and benchmarks, which also takes a long time to build. Enabling this feature also enables test_build.