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Change 'in' (and '!in') filter to work with a hash for performance. #9

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Change 'in' (and '!in') filter to work with a hash for performance. #9

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137 changes: 105 additions & 32 deletions index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -3,59 +3,128 @@
var VectorTileFeatureTypes = ['Unknown', 'Point', 'LineString', 'Polygon'];

function infix(operator) {
return function(_, key, value) {
if (key === '$type') {
return 't' + operator + VectorTileFeatureTypes.indexOf(value);
} else {
return 'p[' + JSON.stringify(key) + ']' + operator + JSON.stringify(value);
return {
vars: empty,
f: function(_, _2, key, value) {
if (key === '$type') {
return 't' + operator + VectorTileFeatureTypes.indexOf(value);
} else {
return 'p[' + JSON.stringify(key) + ']' + operator + JSON.stringify(value);
}
}
};
}

function strictInfix(operator) {
var nonstrictInfix = infix(operator);
return function(_, key, value) {
if (key === '$type') {
return nonstrictInfix(_, key, value);
} else {
return 'typeof(p[' + JSON.stringify(key) + ']) === typeof(' + JSON.stringify(value) + ') && ' +
nonstrictInfix(_, key, value);
var nonstrictInfix = infix(operator).f;
return {
vars: empty,
f: function(_, _2, key, value) {
if (key === '$type') {
return nonstrictInfix(_, _2, key, value);
} else {
return 'typeof(p[' + JSON.stringify(key) + ']) === typeof(' + JSON.stringify(value) + ') && ' +
nonstrictInfix(_, _2, key, value);
}
}
};
}

var hashThreshold = 30;

var operators = {
'==': infix('==='),
'!=': infix('!=='),
'>': strictInfix('>'),
'<': strictInfix('<'),
'<=': strictInfix('<='),
'>=': strictInfix('>='),
'in': function(_, key) {
return '(function(){' + Array.prototype.slice.call(arguments, 2).map(function(value) {
return 'if (' + operators['=='](_, key, value) + ') return true;';
}).join('') + 'return false;})()';
'in': {
vars: function(_, _2, key) {
var valueList = Array.prototype.slice.call(arguments, 3);
if (valueList.length < hashThreshold) {
return [];
}
var values = {};
valueList.forEach(function(value) {
if (key === '$type') {
values[VectorTileFeatureTypes.indexOf(value)] = true;

@tmcw tmcw Jan 27, 2016

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this should be a .forEach if it doesn't return anything, or a for loop. or a reduce if you want it to be functional.

} else {
values[typeof(value) + '' + value] = true;
}
});
return [{
name: 'v' + arguments[0].length,
value: values
}];
},
f: function (_, _2, key) {
var valueList = Array.prototype.slice.call(arguments, 3);
if (valueList.length < hashThreshold) {
return '(function(){' + valueList.map(function(value) {
return 'if (' + operators['=='].f(_, _2, key, value) + ') return true;';
}).join('') + 'return false;})()';
} else {
if (key === '$type') {
return '!!v' + arguments[0].length + '[t]';
} else {
return '!!v' + arguments[0].length + '[typeof(p[' + JSON.stringify(key) + ']) + "" + p[' + JSON.stringify(key) + ']]';
}
}
}
},
'!in': function() {
return '!(' + operators.in.apply(this, arguments) + ')';
'!in': {
vars: function() { return operators.in.vars.apply(this, arguments) },
f: function () {
return '!(' + operators.in.f.apply(this, arguments) + ')';
}
},
'any': function() {
return Array.prototype.slice.call(arguments, 1).map(function(filter) {
return '(' + compile(filter) + ')';
}).join('||') || 'false';
'any': {
vars: empty,
f: function () {
return Array.prototype.slice.call(arguments, 2).map(function (filter) {
return '(' + subcompile(arguments[0], filter) + ')';
}).join('||') || 'false';
}
},
'all': function() {
return Array.prototype.slice.call(arguments, 1).map(function(filter) {
return '(' + compile(filter) + ')';
}).join('&&') || 'true';
'all': {
vars: empty,
f: function() {
return Array.prototype.slice.call(arguments, 2).map(function(filter) {
return '(' + subcompile(arguments[0], filter) + ')';
}).join('&&') || 'true';
}
},
'none': function() {
return '!(' + operators.any.apply(this, arguments) + ')';
'none': {
vars: empty,
f: function() {
return '!(' + operators.any.f.apply(this, arguments) + ')';
}
}
};

function compile(filter) {
return operators[filter[0]].apply(filter, filter);
function subcompile(allVars, filter) {
var op = operators[filter[0]];
var args = filter.slice();
args.unshift(allVars);
var f = op.f.apply(filter, args);
var vars = op.vars.apply(filter, args);
if (vars) {
allVars.push.apply(allVars, vars);
}
return f;
}

function compile(allVars, filter) {
var f = subcompile(allVars, filter);
return {
vars: allVars,
f: f
};
}

function empty() {
return [];
}

function truth() {
Expand All @@ -72,7 +141,11 @@ function truth() {
*/
module.exports = function (filter) {
if (!filter) return truth;
var filterStr = 'var p = f.properties || f.tags || {}, t = f.type; return ' + compile(filter) + ';';
var compiled = compile([], filter);
var vars = compiled.vars.map(function(v) {
return 'var ' + v.name + ' = ' + JSON.stringify(v.value);
});
var filterStr = vars.join(';') + ';(function(f) {var p = f.properties || f.tags || {}, t = f.type;return ' + compiled.f + '});';
// jshint evil: true
return new Function('f', filterStr);
return eval(filterStr);
};