function compose(f, g) { return function(x) { return f(g(x)); }; } function not(x) { return !x; } function on(g, f) { return function(x,y) { return g(f(x), f(y)); }; } function max(f, a, b) { if (f(a) >= f(b)) return a; return b; } function maxBy(f, xs) { if (xs.length < 1) return false; return xs.reduce(function(maxval, a) { return max(f, maxval, a); }); } function len(xs) { return xs.length; } function takeWhile(f, xs) { var result = []; for (var i = 0; i < xs.length; i++) { if (f(xs[i])) result.push(xs[i]); else break; } return result; } function dropWhile(f, xs) { for (i = 0; i < xs.length; i++) { if (!f(xs[i])) break; } return xs.slice(i); } function span(f, xs) { return [takeWhile(f, xs), dropWhile(f, xs)]; } function eq(a) { return function(b) { return a[0] === b[0]; }; } function groupBy(eq, xs) { var groups = []; var spanned; while (xs.length > 0) { spanned = span(eq(xs[0]), xs.slice(1)); groups.push([xs[0]].concat(spanned[0])); xs = spanned[1]; } return groups; } function groupOps(ops) { return groupBy(eq, ops.sort()); } // See: https://en.wikipedia.org/wiki/Trie function buildTrie(prefix, operators) { var grps = groupOps(operators); return [prefix, grps.map( function(ops) { if (ops.length === 1) return ops; return buildTrie(ops[0][0], ops.map( function(op) { return op.slice(1); }).filter(function (x){ return x;})); })]; } function find(f, haystack) { for(var i = 0; i < haystack.length; i++) { if (f(haystack[i])) return i; } return false; } function matchNext(c, trie) { var next = find(function(path) { if (path.length === 1) { return path[0][0] === c; } return path[0] === c; }, trie); return trie[next]; } var trie = buildTrie("", ["**a","**%*^", "$$"])[1]; console.log(find(function(x) { return x === "a";}, "tybabb")); console.log(matchNext("%", matchNext("*", matchNext('*',trie)[1])[1])); //console.log(trie); //function matchStr(n, str, trie) { //} //console.log(matchStr(0, "**^*$4545", buildTrie("", ["**", "**^"])[1])); module.exports = {compose : compose, not : not, on : on, maxBy : maxBy, len : len, groupOps : groupOps, buildTrie : buildTrie}