blancas.morph.monads documentation
->Either
(->Either left right)
Positional factory function for class blancas.morph.monads.Either.
->Identity
(->Identity value)
Positional factory function for class blancas.morph.monads.Identity.
->Maybe
(->Maybe value)
Positional factory function for class blancas.morph.monads.Maybe.
->Reader
(->Reader f)
Positional factory function for class blancas.morph.monads.Reader.
->State
(->State f)
Positional factory function for class blancas.morph.monads.State.
->Writer
(->Writer value output)
Positional factory function for class blancas.morph.monads.Writer.
ask
Returns a Reader whose value is the environment.
asks
(asks f)
Returns a Reader whose value the result of applying f
to the current environment.
either
macro
(either [v m] right-form)(either [v m] left-form right-form)
Evaluates m. If the result is Left, binds its Left contents
to v and evaluates left-form; otherwise binds its Right
contents to v and evaluates right-form.
eval-state
(eval-state m s)
Performs an action m with an initial state s. Returns the value.
eval-writer
(eval-writer m)
Returns the value of a writer.
exec-state
(exec-state m s)
Performs an action m with an initial state s. Returns the state.
exec-writer
(exec-writer m)
Returns the output of a writer.
get-state
Produces an action to return current state as the value.
gets
(gets f)
Like get-state, but applies the function f (usually a selector)
on the state being return as the value of the inner monad.
id
Alias for the Identity constructor.
just
(just x)
Maybe constructor. If x is not nil, it creates a Just value.
If x is nil it creates a Nothing.
just?
(just? m)
Checks for a maybe with a value.
justs
(justs coll)
Filters Just values from a collection. Returns unboxed values.
left
(left x)
Constructor for a Left value.
left?
(left? x)
Tests if the receiver is a Left value.
lefts
(lefts coll)
Extracts the Left values from a collection. Returns unboxed values.
listen
(listen m)
Allows chained Writers to peek at the current output w
by returning a value as a pair (v, w).
local
(local f m)
Returns a Reader whose value is the result of running the Reader m
under a changed environment, which is produced by applying f on
the previous environment.
make-either
macro
(make-either form)(make-either message form)(make-either message pred form)
Either constructor for a boxed value. It takes a value or a form
that may evaluate to nil or throw an exception, both of which
cases result in a Left value. Otherwise it is a Right value.
map-either
(map-either f coll)
Maps an Either-producing function over a collection.
Returns a sequence with Left values removed, as unboxed values.
map-maybe
(map-maybe f coll)
Maps a Maybe-producing function over a collection.
Filters out Nothing values and returns unboxed values.
may
macro
(may [x m] then-form)(may [x m] then-form else-form)
Like if-let for Maybe values. If m has a value, binds it to x
and evaluates the then-form. Otherwise, evaluates the optional
else-form.
maybe
macro
(maybe form)(maybe pred form)
Maybe constructor for a boxed value. It takes a value or a form
that may evaluate to nil or throw an exception, both of which
cases result in a Nothing value.
modify-state
(modify-state f & more)
Produces an action to apply f to the current state, using any
given (optional) arguments. The result becomes the new state.
nothing
Maybe constructor for no value.
nothing?
(nothing? m)
Checks for a maybe with nothing.
pass
(pass m)
Performs an action that returns a Writer similar to (listen),
but instead of output it adds an output-transforming function
to the value's pair. Returns a Writer whose output is the
result of that function.
put-state
(put-state s)
Produces an action to set the current state.
reader
(reader x)
The Reader monad constructor.
right
(right x)
Constructor for a Right value.
right?
(right? x)
Tests if the receiver is a Right value.
rights
(rights coll)
Extracts the Right values from a collection. Returns unboxed values.
run-id
(run-id m)
Returns the value held by an Identity type.
run-just
(run-just m)
Returns the boxed value of m.
run-left
(run-left m)
Accessor for the Left value.
run-reader
(run-reader m e)
Performs a Reader action m with an environment e.
Returns the value produced by the action.
run-right
(run-right m)
Accessor for the Right value.
run-state
(run-state m s)
Performs an action m with an initial state s.
Returns a pair with the value and the state.
state
(state x)
State monad constructor.
tell
(tell x)
Returns a Writer with output x.
writer
(writer a)(writer a w)
Writer monad constructor for value a and output w.
The value w must implement Monoid. If w is not
supplied, it defaults to the empty vector.