webppl

Probabilistic programming for the web

Quick start

Install using nodejs:

npm install -g webppl

Run webppl programs:

webppl myprogram.wppl

Upgrade webppl:

npm update -g webppl

License

webppl is released under the MIT License.

Contributions

We encourage you to contribute to webppl! Check out our guidelines for contributors.

Installation from GitHub

git clone https://github.com/probmods/webppl.git
cd webppl
npm install
npm install -g nodeunit grunt-cli

To use the webppl command line tool from any directory, add the webppl directory to your $PATH.

Usage

Running webppl programs:

webppl examples/geometric.wppl

Compiling webppl programs to Javascript:

webppl examples/geometric.wppl --compile --out geometric.js

The compiled file can be run using nodejs:

node geometric.js

Development

Before committing changes, run grunt (which runs tests and linting):

grunt

If grunt doesn't succeed, the continuous integration tests will fail as well.

To only run the tests, do:

npm test

To only run the linter:

grunt gjslint

If the linter complains about style errors (like indentation), you can fix many of them automatically using:

grunt fixjsstyle

To compile webppl for use in browser, run:

npm install -g browserify
browserify -t brfs src/main.js > compiled/webppl.js

Debugging

To debug WebPPL programs running in Chrome, enable pause on JavaScript exceptions in the Chrome debugger. To debug WebPPL programs running in nodejs, use node-inspector as follows:

// 1. Install node-inspector (only need to do this once)
npm install -g node-inspector

// 2. Compile your webppl program to Javascript
webppl my-program.wppl --compile --out my-program.js

// 3. Add "debugger;" statements to my-program.js to indicate breakpoints

// 4. Run your compiled program in debug mode (will pause automatically)
node --debug-brk my-program.js

// 5. (In separate terminal:) Load node inspector, resume program execution in node-inspector
node-inspector

Using external functions

WebPPL code

You can automatically prepend a webppl file myLibrary.wppl to your code using the following command:

webppl myFile.wppl --require-wppl myLibrary.wppl

Javascript functions and libraries

Using the example of reading and writing CSV files:

1. Install any node modules you want to use:

    npm install -g babyparse
   

2. Write a Javascript file that exports the functions you want to use:

    // simpleCSV.js
    
    var fs = require('fs');
    var babyparse = require('babyparse');
    
    function readCSV(filename){
      return babyparse.parse(fs.readFileSync(filename, 'utf8'));
    };
    
    function writeCSV(jsonCSV, filename){
      fs.writeFileSync(filename, babyparse.unparse(jsonCSV) + "\n");
    }
    
    module.exports = {
      readCSV: readCSV,
      writeCSV: writeCSV
    };
   

3. Write a WebPPL file that uses your new functions (with module qualifier):

    // csvTest.wppl
    
    var myCSVdata = simpleCSV.readCSV('myinput.csv');
    var myNewData = myCSVdata.data.concat([["foo", 3], ["bar", 10]]);
    simpleCSV.writeCSV(myNewData, 'myoutput.csv');
   

4. Run your WebPPL file with require command line flag:

    webppl csvTest.wppl --require-js ./simpleCSV.js
   

Additional header files

Sometimes, it is useful to define external functions that are able to access the store, continuation, and address arguments that are present at any point in a webppl program but usually not exposed to the user. Let's use the example of a function that makes the current address available in WebPPL:

1. Write a Javascript file that exports the functions you want to use:

    // addressHeader.js
    
    function myGetAddress(store, k, address){
      k(store, address);
    };
    
    module.exports = {
      myGetAddress: myGetAddress
    };
   

2. Write a WebPPL file that uses your new functions (without module qualifier):

    // addressTest.wppl
   
    var foo = function(){
      var bar = function(){
        console.log(myGetAddress());
      }
      bar()
    }
    
    foo()
   

3. Run your WebPPL file with require-header command line flag:

    webppl addressTest.wppl --require-header ./addressHeader.js