This tool lets you interact with values and functions directly.
Install
Install Elm Platform to get elm-repl
. Then make sure you have
node.js installed because it is needed to
evaluate the generated JS.
Use
You can type in expressions, definitions, ADTs, and module imports using normal Elm syntax.
> 1 + 1
2 : number
> "hello" ++ "world"
"helloworld" : String
The same can be done with definitions and ADTs:
> fortyTwo = 42
42 : number
> f n = n + 1
<function> : number -> number
> f 41
42 : number
> factorial n = \
| if n < 1 then 1 \
| else n * factorial (n-1)
<function> : number -> number
> factorial 5
120 : number
> type Either a b = Left a | Right b
> case Left 32 of \
| Left n -> 2 * n \
| Right m -> m + 1
64 : number
You can import standard libraries and any library
reachable from the directory where elm-repl
is running:
> import String
> String.length "hello"
5 : Int
> String.reverse "flow"
"wolf" : String