carto/lib/mess/tree/operation.js
2011-01-18 14:26:57 -05:00

33 lines
832 B
JavaScript

(function(tree) {
tree.Operation = function(op, operands) {
this.op = op.trim();
this.operands = operands;
};
tree.Operation.prototype.eval = function(env) {
var a = this.operands[0].eval(env),
b = this.operands[1].eval(env),
temp;
if (a instanceof tree.Dimension && b instanceof tree.Color) {
if (this.op === '*' || this.op === '+') {
temp = b, b = a, a = temp;
} else {
throw { name: 'OperationError',
message: "Can't substract or divide a color from a number" };
}
}
return a.operate(this.op, b);
};
tree.operate = function(op, a, b) {
switch (op) {
case '+': return a + b;
case '-': return a - b;
case '*': return a * b;
case '/': return a / b;
}
};
})(require('mess/tree'));