implicit-predicates-core

The no_std, dependency-free core of implicit-predicates: the arithmetic building blocks shared by the predicates and by generated code.

Status: early development. The API is incomplete and may change.

Currently it provides:

• Sign, the result type of every predicate;
• eft, error-free transformations: floating-point sums and products together with their exact rounding errors;
• expansion, exact values represented as sums of f64 components, with exact addition, subtraction, scaling and sign, all without allocation;
• Scratch, a bump arena over a borrowed buffer that holds the expansions of a computation and runs those operations on them, as well as the exact product of two expansions.

The exact products require operands in a documented range, the product domain (eft::in_product_domain); debug builds check it.

The optional alloc feature adds Scratch::growable, an arena that grows on the heap so the exact arithmetic can always complete. Without it the crate never allocates.

Most users should depend on implicit-predicates instead.

License

Licensed under either of Apache License, Version 2.0 or MIT license, at your option.