Criterion.Types

Types for benchmarking.

The core class is Benchmarkable, which admits both pure functions and IO actions.

For a pure function of type a -> b, the benchmarking harness calls this function repeatedly, each time with a different Int argument, and reduces the result the function returns to weak head normal form. If you need the result reduced to normal form, that is your responsibility.

For an action of type IO a, the benchmarking harness calls the action repeatedly, but does not reduce the result.

Documentation

class Benchmarkable a where

A benchmarkable function or action.

Methods

run

Arguments

:: a

The function or action to benchmark.

-> Int

The number of times to run or evaluate it.

-> IO ()

Run a function or action the specified number of times.

Instances

Benchmarkable Pure

Benchmarkable (IO a)

data Benchmark where

A benchmark may consist of either a single Benchmarkable item with a name, created with bench, or a (possibly nested) group of Benchmarks, created with bgroup.

Constructors

Benchmark :: Benchmarkable b => String -> b -> Benchmark

BenchGroup :: String -> [Benchmark] -> Benchmark

Instances

Show Benchmark

data Pure

A container for a pure function to benchmark, and an argument to supply to it each time it is evaluated.

Instances

Benchmarkable Pure

whnf :: (a -> b) -> a -> Pure

Apply an argument to a function, and evaluate the result to weak head normal form (WHNF).

nf :: NFData b => (a -> b) -> a -> Pure

Apply an argument to a function, and evaluate the result to head normal form (NF).

nfIO :: NFData a => IO a -> IO ()

Perform an action, then evaluate its result to head normal form. This is particularly useful for forcing a lazy IO action to be completely performed.

whnfIO :: NFData a => IO a -> IO ()

Perform an action, then evaluate its result to weak head normal form (WHNF). This is useful for forcing an IO action whose result is an expression to be evaluated down to a more useful value.

bench

Arguments

:: Benchmarkable b

=> String

A name to identify the benchmark.

-> b

-> Benchmark

Create a single benchmark.

bgroup

Arguments

:: String

A name to identify the group of benchmarks.

-> [Benchmark]

Benchmarks to group under this name.

-> Benchmark

Group several benchmarks together under a common name.

benchNames :: Benchmark -> [String]

Retrieve the names of all benchmarks. Grouped benchmarks are prefixed with the name of the group they're in.