Data.Registry.Make

This module provides functions to make values out of a registry. The general algorithm is the following

1. for a given value type search in the existing list of values a value with the same type. If found return it
2. if not found search a function having the desired output type if found, now try to recursively make all the input parameters. Keep a context of the current type trying to be built.
3. when trying to make an input parameter if the current input type is already in the types trying to be built then there is a cycle. Throw an exception in that case
4. when a value has been constructed place it on top of the existing value list so that it can be reused by other functions

Documentation

make :: forall a ins out. (Typeable a, Contains a out, Solvable ins out) => Registry ins out -> a

For a given registry make an element of type a We want to ensure that a is indeed one of the return types We also try to statically check if there aren't other possible errors

makeFast :: forall a ins out. (Typeable a, Contains a out) => Registry ins out -> a

Same as make but without the solvable constraint to compile faster in tests for example

makeEither :: forall a ins out. Typeable a => Registry ins out -> Either Text a

This version of make only execute checks at runtime this can speed-up compilation when writing tests or in ghci

makeUnsafe :: forall a ins out. Typeable a => Registry ins out -> a

This version of make only execute checks at runtime this can speed-up compilation when writing tests or in ghci