This module exposes some useful tracing functions that should have been exported by Debug.Trace.
Feel free to copy&paste these functions into modules that need them, that may be easier to remove/clean up than adding a cabal dependency.
- traceId :: Show a => String -> a -> a
- traceIdVia :: Show b => (a -> b) -> String -> a -> a
- traceAround :: (Show i, Show o) => String -> (i -> o) -> i -> o
Documentation
Generate an identity function that has the side-effect of showing the value that passes through it.
Examples:
traceId "x,y = " (x, y)
:: Show b | |
=> (a -> b) | Function to preprocess the value before showing it |
-> String | Prefix string to use before showing the result value |
-> a | |
-> a |
Generate an identity function that has the side-effect of tracing the value that passes through it by first processing it and then showing the result.
Examples:
traceIdVia (take 5) "First 5 sorted elements of: " result
fmap (traceIdVia objName "The object we got") . receiveObject
traceAround :: (Show i, Show o) => String -> (i -> o) -> i -> oSource
Convert a pure function to one that also has a side effect of tracing the value of the input and output values that pass through the function.
Examples:
traceAround "filterEntries" filterEntries entries