Parsimmon stack trace

// Run me with Node to see my output! let util = require("util"); let P = require("parsimmon"); /////////////////////////////////////////////////////////////////////// let Lisp = P.createLanguage({ // An expression is just any of the other values we make in the language. Note // that because we're using `.createLanguage` here we can reference other // parsers off of the argument to our function. `r` is short for `rules` here. Expression: function(r) { return P.alt(r.Symbol, r.Number, r.List); }, // The basic parsers (usually the ones described via regexp) should have a // description for error message purposes. Symbol: function() { return P.of().map(x => { console.trace(); console.log(x); return x; }).then(P.regexp(/[a-zA-Z_-][a-zA-Z0-9_-]*/).desc("symbol")); }, // Note that Number("10") === 10, Number("9") === 9, etc in JavaScript. // This is not a recursive parser. Number(x) is similar to parseInt(x, 10). Number: function() { return P.regexp(/[0-9]+/) .map(Number) .desc("number"); }, // `.trim(P.optWhitespace)` removes whitespace from both sides, then `.many()` // repeats the expression zero or more times. Finally, `.wrap(...)` removes // the '(' and ')' from both sides of the list. List: function(r) { return r.Expression .trim(P.optWhitespace) .many() .wrap(P.string("("), P.string(")")); }, // A file in Lisp is generally just zero or more expressions. File: function(r) { return r.Expression.trim(P.optWhitespace).many(); } }); /////////////////////////////////////////////////////////////////////// let text = `\ (list 1 2 (cons 1 (list))) (print 5 golden rings) `; Lisp.File.tryParse(text);