Crate merc_utilities 

Overview

⚠️ important This is an internal crate and is not intended for public use.

Internal crate for the MERC toolset that provides utility types and functions for the Merc toolset.

One important utility is the MercError type, which is a common error type used throughout the MERC toolset. This type provides thin pointers for dyn Error trait objects, which helps to reduce memory usage and improve performance when handling errors. Furthermore, it provides a stack trace by default, which can be very useful for debugging and diagnosing issues.

An important testing function is the random_test function, which can be used in tests to provide (reproducible) random state. This is useful for testing code that relies on randomness, as it allows for consistent and repeatable tests. Finally, it provides a Timing struct that can be used to measure and record the time taken by various operations in the MERC toolset.

Furthermore, the DumpFiles struct can be used to manage dumping of intermediate results to files, which can be very useful for debugging failing tests. It uses an environment variable MERC_DUMP to determine the absolute path to dump the files.

Safety

This crate contains no unsafe code. If unsafe code is needed it should be in the merc_unsafety crate.

Minimum Supported Rust Version

We do not maintain an official minimum supported rust version (MSRV), and it may be upgraded at any time when necessary.

License

All MERC crates are licensed under the BSL-1.0 license. See the LICENSE file in the repository root for more information.

Macros

cast

A macro to return the pat type of an enum class target, and panics otherwise.

debug_trace

debug_use

Structs

DisplayPair

A struct that can be used to pretty print the parse tree obtained from the pest crate.

GenerationCounter

A counter that keeps track of generational indices. This helps manage generations of indices to detect use-after-free and similar issues.

GenerationalIndex

A generational index that stores both an index and a generation counter. The generation is only tracked in debug builds to avoid overhead in release.

MercError

The Merc error type. This has a blanket From impl for any type that implements Rust’s Error, meaning it can be used as a “catch all” error. Captures a backtrace that can be printed from this object.

NoHasher

A hasher that directly uses the value provided to write_u64 as the hash

NoHasherBuilder

A builder for NoHasher. Starts with a hash of 0 and returns whatever value is passed to write_u64

TagIndex

An index is an index that can only be compared with equivalent tags. Note that the constructor does not requires us to provide a tag, and as such anyone can make a tagged index. It is not a proof of a valid index. This could be extended in the future.

Timing

A timing object to measure the time of different parts of the program. This is useful for debugging and profiling.

Traits

MercIndex

A trait for index types.

Functions

is_valid_permutation

Returns true iff the given permutation is a bijective mapping within the 0..max range.

random_test

Constructs a random number generator that should be used in random tests. Prints its seed to the console for reproducibility.

random_test_threads

test_logger

Constructs a logger for tests. This logger will not print anything to the console, but will instead write to a buffer.

test_threads

Type Aliases

PhantomUnsend

Indicates that a type is !Send

PhantomUnsync

Indicates that a type is !Sync