IPython/frontend/html/notebook/static/js/context-hint.js

// highly adapted for codemiror jshint

(function () {
    "use strict";
    function forEach(arr, f) {
        for (var i = 0, e = arr.length; i < e; ++i) f(arr[i]);
    }
    
    function arrayContains(arr, item) {
        if (!Array.prototype.indexOf) {
            var i = arr.length;
            while (i--) {
                if (arr[i] === item) {return true;}
            }
            return false;
        }
        return arr.indexOf(item) != -1;
    }
    
    CodeMirror.contextHint = function(editor) {
        // Find the token at the cursor
        var cur = editor.getCursor(), token = editor.getTokenAt(cur), tprop = token;
        // If it's not a 'word-style' token, ignore the token.
        // If it is a property, find out what it is a property of.
        var list = new Array();
        var clist = getCompletions(token,editor);
        for(var i = 0 ; i < clist.length ; i++)
        {
            list.push(
                { str  : clist[i],
                  type : "context",
                  from : {line: cur.line, ch: token.start},
                  to   : {line: cur.line, ch: token.end} })
        }
        return list;
    }

    // find all 'words' of current cell
    function getAllTokens(editor)
    {
        var found = [];
        // get all text remove and split it before dot and at space
        // keep the dot for completing token that also start with dot
        var candidates = editor.getValue()
                .replace(/[.]/g," .")
                .replace(/[ ]/g,"\n")
                .split('\n'); 
        // append to arry if not already (the function)
        function maybeAdd(str) {
            if (!arrayContains(found, str)) found.push(str);
        }
        // append to arry if not already 
        // (here we do it )
        for( var c in candidates )
        {
            if(candidates[c].length >= 1){
            maybeAdd(candidates[c]);}
        }
        return found;
    }

    function getCompletions(token,editor) 
    {
        var candidates = getAllTokens(editor);
        // filter all token that have a common start (but nox exactly) the lenght of the current token
        var lambda = function(x){ 
            return (x.indexOf(token.string)==0 && x != token.string)
            };
        var filterd = candidates.filter(lambda);
        return filterd;
    }
})();