A REPL for Dart.

This package is no longer being maintained. Please see https://pub.dev/packages/interactive for a more full featured and ready to use REPL for Dart.

Prior art

Based on early version of a proof of concept REPL environment for Dart from a pair of articles by Andreas Kirsch and an example in the Dart SDK tests and the recharge package

Features

MVP with expression evaluation
Use code from BlackHC's work to parse input for statements vs expressions
Use cli_repl for better repl ergonomics
Use standard pub activate for package to run its binary instead of shell script
Improve usage documentation
Use hotreload with a scratchpad file
?? Support built in package imports
?? Support arbitrary package imports
?? Use scratchpad with dedicated Isolate

?? - not clear if this is a workable approach

Usage

To install the repl use:

dart pub global activate repl

Then as long as the pub system cache is on your path you can run it using: drepl

Supported features

You can currently use expressions and statements as well as a few built-in's are supported (see below), its already possible to do a few useful things with the REPL.

For instance you can do JS style IIFE's:

> (){final data = ['this', 'is', 'a', 'test']; for(int i = 0; i < data.length; i++) print(data[i]); }()

But of course that is a bit contrived an example as you could also do:

> ['this', 'is', 'a', 'test'].forEach((x) => print(x))

Some statements are also possible, eg.

> int sqr(int a) => a*a;

> sqr(5)
> 25

Built-in's

print() - print to output reload() - trigger a hot-reload (doesn't work well at the moment)

Editing, History, Shortcuts

see the cli_repl package documentation for supported short-cut keys.

Development

Clone this repo, then from the top level of this repo and then run using:

dart bin/main.dart

Future plans

A more powerful though much more involved implmentation route would be to use the Dart embedding API, perhaps via FFI to avoid needing to deal with too much c/c++ dev, assuming its possible for DartVM to call into itself via FFI using the embedding api?

Contributing

All contributions: PRs, bug reports, feature requests, documentation are most welcome.

Contribution guidelines: TODO.

maks/dart_repl