reacl-c-basics.programs.core — de.active-group/reacl-c-basics 0.10.8

Programs are an abstraction over items, that have a dedicated result, and form an async monad.

You will usually start with an item that allows some user interactions when the program is 'running', like

(c/defn-item my-form [running?]
  (dom/button {:disabled (not running?)
               :onClick (fn [v _] (c/return :action "done"))}))

Then define a program that runs that

(defn-program my-program []
  [res (await-action my-form)]
  (show (dom/div res)))

And then add running this program into your application

(dom/div "My program:" (runner (my-program)))

await-action clj/s

(await-action f & [pred])

A program that shows the item returned by (f running?), until it emits an action where the given predicate holds, which is then returned as the programs result. If no predicate is specified, then any action will be taken as the result of the program.

await-state clj/s

(await-state f & [done-state?])

A program that shows the item returned by (f running?), until its state is a non-nil value, or the given predicate holds, returning that value as the program's result.

defn-program clj/s macro

(defn-program name params & body)

A macro just like defn, but where the body is wrapped in do-program.

do-program clj/s macro

(do-program form & forms)

A monadic do notation for programs.

For example:

(do-program
  [r1 (return 21)]
  (return (* r1 2)))

fmap clj/s

(fmap f program)

A program that applies f to the result of the given program.

par clj/s

(par & programs)

program? clj/s

(program? v)

A predicate for programs.

race clj/s

(race program & programs)

A program running several programms in parallel, until the first one is finished, returning the result of that 'winner'.

return clj/s

(return v)

A program that immediately returns the given value once when run.

runner clj/s

(runner program & [handle-result-f])

An item that runs the given program once, offering an event handler for handling the result of the program.

sequ clj/s

(sequ program & programs)

A program consisting of several programs run one after the other, returning the result of the last one.

show clj/s

(show item)

A program that just shows the given item, but never completes.

sleep cljs

(sleep ms)

A program that returns nil after the given number of milliseconds have elapsed.

then clj/s

(then program cont)

A program that runs program first, and then the program (cont result), where result is the result of the first program.

trampoline clj/s

(trampoline program)

A trampoline can be used to make programs that use mutual recursion run without consuming any stack or heap, thus can potentially run forever. This returns a program that runs the given program until it returns. If it returns another program, then the execution is continues with that program. If it returns something else, then the program completes.

wrap clj/s

(wrap f program)

A program wrapped in some additional markup, via (f item), where item is the item representing the program in either the running or the non-running state.

wrap* clj/s

(wrap* f program)

A program wrapped in some additional markup, via (f item running?), where item is the item representing the program, and running? a boolean specifying if the program is in the running state or not.