active.clojure.monad — de.active-group/active-clojure 0.42.2

Monad related functionality, particularly free monads.

and-finally clj/s

(and-finally m final-m)

Execute m, and always final-m, no matter if an exception occurs or not.

bind-except clj/s

(bind-except m handler f)

Evaluate m, and if an exception occurs continue with (handler exception), otherwise with (f value-of-m). Note that neither the handler result is to f, nor exceptions are caught in f.

call-cc clj/s

(call-cc f)

Construct a CallCC (Accepts a function f with one argument that returns a monadic value. call-cc packages the current continuation as a function and passes it as an argument to f. If the function is called later, the continuation of that call will be discarded and instead reinstate the continuation that was in effect when the function was created.) record.

f: access via active.clojure.monad/call-cc-f

call-cc-f clj/s≠

clj

(call-cc-f rec__3628__auto__)

(call-cc-f data__3629__auto__ v__3630__auto__)

cljs

(call-cc-f rec__3284__auto__)

(call-cc-f data__3285__auto__ v__3286__auto__)

Lens for the f field from a [[CallCC]] record. See active.clojure.monad/call-cc.

call-cc? clj/s

(call-cc? thing)

Is object a CallCC record? See active.clojure.monad/call-cc.

combine-monad-command-configs clj/s

(combine-monad-command-configs & mccs)

Combine a sequence of monad-command configs into one. The earlier entries have precedence.

execute-free-reader-state-exception clj/s

(execute-free-reader-state-exception command-config m & [state])

Run monadic computation in a reader-state-exception monad, turning exceptions into Clojure exceptions.

• command-config is the configuration object for running commands
• m is the computation to run
• state is an optional initial state (from a previous run)

Returns [result state].

execute-monadic clj/s

(execute-monadic command-config m & [state])

Run monadic computation in an almighty monad, turning exceptions into Clojure exceptions. See [[run-monadic]].

• command-config is the configuration object for running commands
• m is the computation to run
• state is an optional initial state (from a previous run)

Returns [result state].

free-bind clj/s

(free-bind mv f)

Bind/flatMap for the free monad.

free-bind-cont clj/s≠

clj

(free-bind-cont rec__3628__auto__)

(free-bind-cont data__3629__auto__ v__3630__auto__)

cljs

(free-bind-cont rec__3284__auto__)

(free-bind-cont data__3285__auto__ v__3286__auto__)

Lens for the cont field from a [[Bind]] record. See active.clojure.monad/make-free-bind.

free-bind-monad clj/s≠

clj

(free-bind-monad rec__3628__auto__)

(free-bind-monad data__3629__auto__ v__3630__auto__)

cljs

(free-bind-monad rec__3284__auto__)

(free-bind-monad data__3285__auto__ v__3286__auto__)

Lens for the monad field from a [[Bind]] record. See active.clojure.monad/make-free-bind.

free-bind? clj/s

(free-bind? thing)

Is object a Bind record? See active.clojure.monad/make-free-bind.

get-env-component clj/s

(get-env-component name)

Retrieve a named component of a map-valued environment.

get-state-component clj/s

(get-state-component name)

Retrieve a named component of a map-valued state.

intermediate-result-resume clj/s≠

clj

(intermediate-result-resume rec__3628__auto__)

(intermediate-result-resume data__3629__auto__ v__3630__auto__)

cljs

(intermediate-result-resume rec__3284__auto__)

(intermediate-result-resume data__3285__auto__ v__3286__auto__)

Lens for the resume field from a [[IntermediateResult]] record. See active.clojure.monad/make-intermediate-result.

intermediate-result-thing clj/s≠

clj

(intermediate-result-thing rec__3628__auto__)

(intermediate-result-thing data__3629__auto__ v__3630__auto__)

cljs

(intermediate-result-thing rec__3284__auto__)

(intermediate-result-thing data__3285__auto__ v__3286__auto__)

Lens for the thing field from a [[IntermediateResult]] record. See active.clojure.monad/make-intermediate-result.

intermediate-result? clj/s

(intermediate-result? thing)

Is object a IntermediateResult record? See active.clojure.monad/make-intermediate-result.

make-free-bind clj/s

(make-free-bind monad cont)

Construct a Bind record.

monad: access via active.clojure.monad/free-bind-monad cont: access via active.clojure.monad/free-bind-cont

make-intermediate-result clj/s

(make-intermediate-result thing resume)

Construct a IntermediateResult (Possible return value for run-monadic, when monadic program wants to pause calculation. Call intermediate-result-resume with a value [[v]] to resume the paused calculation with [[v]].) record.

thing: access via active.clojure.monad/intermediate-result-thing resume: access via active.clojure.monad/intermediate-result-resume

make-monad-command-config clj/s

(make-monad-command-config run-command env state)

Construct a MonadCommandConfig (Configuration for supporting a set of monad commands.) record.

run-command: access via active.clojure.monad/monad-command-config-run-command env: access via active.clojure.monad/monad-command-config-env state: access via active.clojure.monad/monad-command-config-state

monad-command-config-env clj/s≠

clj

(monad-command-config-env rec__3628__auto__)

(monad-command-config-env data__3629__auto__ v__3630__auto__)

cljs

(monad-command-config-env rec__3284__auto__)

(monad-command-config-env data__3285__auto__ v__3286__auto__)

reader-monad initial environment represented as a mergable map

monad-command-config-run-command clj/s≠

clj

(monad-command-config-run-command rec__3628__auto__)

(monad-command-config-run-command data__3629__auto__ v__3630__auto__)

cljs

(monad-command-config-run-command rec__3284__auto__)

(monad-command-config-run-command data__3285__auto__ v__3286__auto__)

run-command :: run-any env state comp -> (| [(| exception-value? val) state] unknown-command) Where run-any is a function for running any monad command of the signature `env state comp -> (| [(| exception-value? val) state] unknown-command)

monad-command-config-state clj/s≠

clj

(monad-command-config-state rec__3628__auto__)

(monad-command-config-state data__3629__auto__ v__3630__auto__)

cljs

(monad-command-config-state rec__3284__auto__)

(monad-command-config-state data__3285__auto__ v__3286__auto__)

state-monad initial state represented as a mergable map

monad-command-config? clj/s

(monad-command-config? thing)

Is object a MonadCommandConfig record? See active.clojure.monad/make-monad-command-config.

monadic clj/s macro

(monadic & ?stmts)

Construct a monadic computation.

The syntax is (monadic <stmt> ...) where <stmt> is one of the following:

• [<pat> <exp> ...] which creates monadic bindings
• (let <bindings>) which creates regular bindings
• anything else is just a regular expression, expected to yield a monadic value.

Example:

(monadic [first (ask "what's your first name?")
          last (ask "what's your last name?")]
         (let [s (str "Hello, " first " " last)])
         (tell s))

null-monad-command-config clj/s

(null-monad-command-config env state)

Monad command-configuration with no commands except for reader/state/exception.

pause clj/s

(pause thing)

Construct a Pause (Accepts a arbitrary value thing that can be used to mark the type of the [[IntermediateResult]]. pause can be used to pause the current monadic calculation and return an [[Intermediate Result]].) record.

thing: access via active.clojure.monad/pause-thing

pause-thing clj/s≠

clj

(pause-thing rec__3628__auto__)

(pause-thing data__3629__auto__ v__3630__auto__)

cljs

(pause-thing rec__3284__auto__)

(pause-thing data__3285__auto__ v__3286__auto__)

Lens for the thing field from a [[Pause]] record. See active.clojure.monad/pause.

pause? clj/s

(pause? thing)

Is object a Pause record? See active.clojure.monad/pause.

put-state-component! clj/s

(put-state-component! name value)

Set a named component of a map-valued state.

reduce-m clj/s

(reduce-m m-fn acc xs)

Like reduce, but takes a monadic function m-fn for folding the results. Returns the final result.

reified? clj/s

(reified? m)

Checks whether a monadic command is reified.

reify-as clj/s

(reify-as m reification)

Adds reification meta data to m that helps utilities (like the mock runner for tests), to reify a composed command as something comparable (and printable), for cases where the command itself is not; e.g. it includes a bind inside. See [[reify-command]] to extract the meta data again.

Note that reify-as does not work on binds like for example composed monadic programs with monadic. Because the reification meta data sticks at the first bind that is handled by run-monadic and friends above -- and not by the command runners that are mocked away by the mock runner. To improve on that we might either need to add the awareness of mocking into run-monadic and friends above or copy their implementation into to mock namespace and include mocking of binds there.

reify-command clj/s

(reify-command m)

Return the reification object of m, if one was added with [[reify-as]], or m itself otherwise.

return clj/s

run-free-reader-state-exception clj/s

(run-free-reader-state-exception command-config m & [state])

Run monadic computation in a reader-state-exception monad.

• command-config is the configuration object for running commands
• m is the computation to run
• state an optional initial state (from a previous run) that is merged into the one from command-config

Returns [result state]

run-monadic clj/s

(run-monadic command-config m & [state])

Run a monadic computation in an almighty monad. Same as [[run-free-reader-state-exception]] with the addition of call-cc and pause.

• command-config is the configuration object for running commands
• m is the computation to run
• state an optional initial state (from a previous run) that is merged into the one from command-config

Returns [result state]

run-no-commands clj/s

(run-no-commands _run-any _env _state _m)

For use in make-monad-command-config when there are no commands.

scan-m clj/s

(scan-m m-fn acc xs)

Like reduce-m, but returns a sequence of each intermediate result. The actual result is the last element of that sequence.

(last (scan-m f zero xs)) = (reduce-m f zero xs) holds.

sequ clj/s

(sequ ms)

Evaluate each action in the sequence from left to right, and collect the results.

sequ_ clj/s

(sequ_ ms)

Evaluate each action in the sequence from left to right, and ignore the results.

throw-illegal-argument-exception clj/s

(throw-illegal-argument-exception msg)

unknown-command clj/s

Marker that command functions can return to signal they don't recognize a command.

update-state-component! clj/s

(update-state-component! name f & args)

Calls f with the current value of the component and puts back return value as the new component.

with-env-component clj/s

(with-env-component key f m)

Transform a keyed component of a map-valued environment.