Printr-interpreter NPM

JavaScript interpreter for Printr

An interpreter for the Printr language, written in JavaScript.

Build environment

The interpreter was built in the following environment:

Node version 10.14.0
NPM version 6.5.0

Installation and usage

npm install printr-interpreter

In the host system, grab the interpreter and pass it source text written in Printr. The text may come from a string constant, a file, the result of a network request or any other source.

The interpreter shall emit 'print' instructions with text as an argument that can then be interpreted by the host. An example interpretation of a 'print' instruction may be to route the text argument to stdout or alert a user on a web page.

const interpreter = new Printr();

interpreter.on('print', (text) => console.log(text));

interpreter.run('"Hello World!"');

Error handling

When running a Printr program, the interpreter will stop when encountering a syntax error. It's possible to handle syntax errors by registering a handler for the error event:

interpreter.on('error', (error) => console.log(error));

The error handler will receive details of the syntax error as its only argument.

If an error handler has not been registered, a syntax error will be thrown and must be caught within a try/catch block:

try {
  const interpreter = new Printr();

  interpreter.on('print', (text) => console.log(text));

  interpreter.run('"Hello World!"');
}
catch(syntaxError) {
  // ... do something to handle error
}