tree2query.js

#!/usr/bin/env node
var util = require('util');
util.puts("Convert tree to query!");
var tree = {
	type : "and",
	left : {
		type : "eq",
		left : {
			type : "property",
			name : "City"
		},
		right : {
			type : "literal",
			value : "Seattle"
		}
	},
	right : {
		type : "and",
		left : {
			type : "eq",
			left : {
				type : "property",
				name : "State"
			},
			right : {
				type : "literal",
				value : "Washington"
			}
		},
		right : {
			type : "and",
			left : {
				type : "eq",
				left : {
					type : "property",
					name : "FirstName"
				},
				right : {
					type : "literal",
					value : "John"
				}
			},
			right : {
				type : "eq",
				left : {
					type : "property",
					name : "LastName"
				},
				right : {
					type : "literal",
					value : "Doe"
				}
			}
		}
	}
};
var readNode = function(node) {

	if (node.type === "eq") {
		return "(" + node.left.name + " = '" + node.right.value + "')";
	}
	if (node.type === "and") {
		return readNode(node.left) + " and " + readNode(node.right);
	}

};
util.puts(readNode(tree));

var filter = function(querySchema) {
	if (querySchema.type == 'and') {
		// standard binary tree traversal recursion:
		return filter(querySchema.left) + " and " + filter(querySchema.right);
	} else if (querySchema.type == 'eq') {
		return " " + querySchema.left.name + " = " + querySchema.right.value + " ";
	}
}

util.puts(filter(tree));