This is the parser and runtime library implementing the Filament language.

Install with

npm install --save filament-lang

Evaluate code:

await setup_parser()
let ret = await eval_code('42ft')
console.log("we should have a scalar with 42 and feet for the unit:",ret)

produces a scalar object with the value of 42 feet

(ret.value === 42)
(ret.unit  === 'foot')
(ret.dim   === 1)

//as a string
console.log(ret.toString())

Filament has a bunch of built-in functions for math, lists, and data access. You can add your own functions by customizing the scope and passing it into eval_code.

let double = new FilamentFunction('double',
    {value:REQUIRED},
    (a) =>scalar(a.value*2,a.unit,a.dim)
)

let scope = make_standard_scope()
scope.install(double)

console.log("4 doubled is", await eval_code('double(42,ft)',scope))

Read the tutorial. link

Roadmap

• next blog

  • if then else statement. thought a lot about the syntax. block or expression works.
  • lambdas. thought a ton about this. all functions are lambdas now with streamlined syntax. the way to make it easy is to introduce it slowly.
  • no return/break/continue/jump/gotos. no early return of any kind. everything flows through. scratch has no break statement (other than end). I think logo doesn't either.
  • turtle graphics
  • gui: symbol explorer. start of syntax highlighting.
  • print function to go to JS console. just for my own debugging.

• match syntax?

• scene graph for rects and circles and polygons

  • row of rects w/ size defined in centimeters. Customize colors

• random number generator and a series of examples to show noise based code

• image generator function [-] do callback function for every pixel [-] mandlebrot [-] Make image from random noise [-] Color image based on row or column [-] Color image using equations like with shaders

//make vertical stripes with colors
red << [1,0,0]
green << [0,1,0]
make_image(width:100, height: 100, generate:(x,y) -> {
   if x mod 2 == 0 then red else green
})
//make checkerboard with direct color arrays
make_image(width:100, height: 100, generate:(x,y) -> {
   if x mod 2 == 0 or y mod 2 == 0 
     then [1,1,1]
     else [0,0,0]
})

//white noise
make_image(width:100, height: 100, generate:(x,y) -> {
    n << random(min:0,max:1)
    [n,n,n]
})

load_image(src:'url') >> map(with:(c,x,y) -> {
    [ c[0]*0.25, c[1]*0.25, c[2]*0.5 ]
}) 
 make_color(c.r* 0.25, c.g * 0.25,c.b * 0.5)
 // cross fade
c1*0.5 + c2*0.5
reduce(img1,img2, with:(ca,cb,x,y) {
    
})
map(img1,with(color,x,y) -> {
    color2 = get_pixel(img2,x,y)
    return color*0.5 + color2*0.5
}

brightness << (c)     -> c[0]*0.24 + c[1]*0.24 + c[2]*0.5
lerp       << (t,a,b) -> a * (1-t) + b * (t)

white << [1,1,1]
brown << [0.5,0.4,0.1]

sepia << (c,x,y) -> {
  b << brightness(c)
  lerp(b,white,brown)
}
load_image(src:"url") >> map(with:sepia)  

//mandlebrot will require loops
//do we need a color datatype which is an array plus some accessors?
need array access syntax.  
    identifier [ index ]
//simple raytracer will need loops and records / objects    

Contributing to Filament

Building a browser-compatible UMD module

The Filament source code may be bundled into an application via tools such as Webpack, using an import or require statement. This mechanism should work in both the browser and NodeJS environments.

In addition, it is possible to create a UMD module suitable for use in a browser-side HTML page. This module may be included via a <script> tag, or (untested at this time) may be used in a NodeJS environment via require or import.

To create the UMD module, use the following:

npm run build-umd

This will create a dist/ directory and generate the following files in that directory:

• dist/filament.js

Testing the built UMD module

An HTTP server is necessary to serve the contents of this repository. There are many to choose from, but for the purposes of this document, we will use http-server, which is installed as a development dependency via package.json.

After building the UMD module via npm run build-umd, the following command will serve up the content of the test-umd/ directory:

npm run test-umd

You can then point your web browser at http://127.0.0.1:8080 to see test/index.html.

Publishing a new version to NPMJS

The following instructions are primarily for reference and for use by the primary Filament package author when preparing to publish a new version.

• Update version number in package.json
• Ensure that Mocha tests run successfully npm run test
• Build UMD module via npm run build-umd
• Ensure that browser-side UMD tests run successfully npm run test-umd and connecting to http://127.0.0.1:8080.
• Generate documentation via npm run docs
• Use npm pack --dry-run to view what files would end up in the published package. Adjust .npmignore if there are files listed that should not be published.