The type for configuration keys. Keys are used to parameterize the choice of module implementation.

create n a is the key named n whose contents is determined by parsing the command-line argument a.

The type for configure-time and run-time values. Values are either pure or obtained by composing other values. Values might have data dependencies, which form an (implicit) directed and acyclic graph that need to be evaluated.

pure x is a value without any dependency.

f $ v is is the value resulting from the application of f'value to v's value. $ is the usual app operator for applicative functor.

map f v is pure f $ v.

if_ v x y is map (fun b -> if b then x else y) v.

match_ v pattern is map pattern v.

default v returns the default value for v.

value k is the value parsed by k.

The type for abstract keys.

name t is the string given as t's name when t was created.

v k is the k with its type hidden.

equal is the equality function of untyped keys.

pp fmt k prints the name of k.

Set implements sets over t elements.

of_deps keys is a value with keys as data-dependencies.

deps v are v's data-dependencies.

pp_deps fmt v prints the name of the dependencies of v.

The type for values holding parsing context.

Add a binding to a context.

context ks is a Cmdliner term that evaluates into a parsing context for command-line arguments.

mem c v is true iff all the dependencies of v have been evaluated.

peek c v is Some x if mem v and None otherwise.

eval c v evaluates v in c's context, using default values if necessary.

get c k is k's value in c's context. If k is not present in c, it is k's default value.

find c k is k's value in c's context or None if k is not present in c.

pps c fmt ks prints the keys ks using the context c to get their value.