ASTs and whatever
some fun things you can do with ASTs
me
http://substack.net https://github.com/substack https://npmjs.com/~substack
as a last resort
ASTs let you cheat.
Make sure there's a good reason.
esprima
var fs = require('fs');
var src = fs.readFileSync(__dirname + '/source.js', 'utf8');
var parse = require('esprima').parse;
console.log(parse(src));acorn
var fs = require('fs');
var src = fs.readFileSync(__dirname + '/source.js', 'utf8');
var parse = require('acorn').parse;
console.log(parse(src));DEMO
esprima/acorn demo
cd example/ast
falafel
walk and modify an AST
tree order
a
/ \
b c b d e c a
/ \
d e
falafel
var fs = require('fs');
var src = fs.readFileSync(__dirname + '/source.js', 'utf8');
var falafel = require('falafel');
var output = falafel(src, function (node) {
// ...
});falafel
usual AST properties plus:
node.parentnode.source()node.update()
DEMO
falafel demo
cd example/falafel
browserify
looks for require() calls to build a bundle
DEMO
browserify demo
cd example/browserify
insert-module-globals
looks for:
process__dirname__filenameglobalBuffer
brfs
looks for fs.readFileSync() calls to inline
DEMO
brfs demo
cd example/brfs
static-module
define statically inlined module interfaces
- very handy for "universal" javascript
static-module
var staticModule = require('static-module');
var quote = require('quote-stream');
var fs = require('fs');static-module
var staticModule = require('static-module');
var quote = require('quote-stream');
var fs = require('fs');
var sm = staticModule({
// ...
}, { vars: { __dirname: __dirname } });
process.stdin.pipe(sm).pipe(process.stdout);static-module
var staticModule = require('static-module');
var quote = require('quote-stream');
var fs = require('fs');
var sm = staticModule({
fs: {
readFileSync: function (file) {
return fs.createReadStream(file).pipe(quote())
}
}
}, { vars: { __dirname: __dirname } });
process.stdin.pipe(sm).pipe(process.stdout);DEMO
static-module demo
cd example/sm
bulkify
var bulk = require('bulk-require');
var modules = bulk(__dirname, [ 'pages/*.js', 'lib/*.js' ]);
console.log(modules);DEMO
bulkify demo
cd example/bulk
glslify
webgl shaders using static-module
var glslify = require('glslify')
var src = glslify(__dirname + '/shader.glsl')
console.log(src)static-eval
evaluate static expressions by walking the AST
*
/ \
+ 5
/ \
3 2
DEMO
static-eval demo
cd example/eval
coverify
wraps every expression and statement!
var x = 5;
var y = (x + 10) * 2;
console.log(x / y);turns into:
var x = wrap(1, 5); wrap(2);
var y = wrap(7, wrap(5, wrap(4, x) + wrap(3, 10)) * wrap(6, 2)); wrap(8);
wrap(11, console.log)(wrap(9, x) / wrap(10, y)); wrap(12);DEMO
coverify demo
cd example/coverify
live-patch
update a running program live
by diffing and patching the AST
DEMO
live-patch demo
cd example/patch
EOF