alda-cljs

An experimental ClojureScript port of Alda.

Development

Have Boot installed.
Run boot dev.

This will watch for changes to source files and whenever there is a change, re-render the ClojureScript files to target/main.js.
Open target/test.html in your browser and open the JavaScript console. This file just loads target/main.js -- it's useful as a sandbox for testing the JavaScript code that this library generates.

The boot dev task has a built-in browser reload websocket. Any time a change is made, your browser window will refresh automatically so that you can see the changes right away.

Demo

There are a couple things you can do so far:

Parse a demo score -- uncomment the 3 commented lines in alda-cljs.core and you will see the parse tree printed out to the console.

Parse arbitrary Alda code using the exported alda-cljs.parser/parse function:

  // just return an array representing the parse tree
  alda_cljs.parser.parse('piano: c');

  // also print the ClojureScript representation to the console
  alda_cljs.parser.parse('piano: c', {print: true});

At the moment, the parse trees you see are the raw result of parsing code using the Alda grammar.

What Alda (the Clojure project) does:

Use the Alda grammar to generate a parse tree.
Transform that parse tree into executable Clojure code. (Generating code and evaluating it is a common task in Lisp, where code is data.)
Define a namespace (alda.lisp) full of functions that provide a context for what happens when you evaluate the code. In the alda.lisp namespace, there are functions called score, note, chord, octave, etc.
Eval the generated Clojure code to build the internal representation of the score.

What alda-cljs will do:

Use the Alda grammar to generate a parse tree.
Transform that parse tree into ... ?
????
PROFIT

ClojureScript doesn't have eval (yet?) so this is going to be a little more complicated. We may need to transform the parse tree into a kind of pseudo-Lisp language (it practically already is one), along with a basic Lisp interpreter that manually traverses the Lisp "program," evaluating things conditionally, i.e. "if the first item in the array is :score, then run this score function," etc.

License