(define jslambda
    (jsspform "function(source) {
        var fn = eval('(' + source + ')');
        var fw = function() {
            var args = [];
            for (var i = 0; i < arguments.length; i ++) args.push(arguments[i].eval(this));
            return fn.apply(this, args);
        };
        fw.ctx = this.saveScope();
        return fw;
    }"))

(define if
    (jsspform "function(cond, t, f) {
        var r;
        if(cond.eval(this)) {
            r = t.eval(this);
        }
        else {
            r = f.eval(this)
        }
        return r;
    }"))

(define set!
    (jsspform "function(symbol, from, to) {
        this.set(symbol, value.eval(this));
        return 0;
    }"))

(define lambda
    (jsspform "function() {
        var args = Array.shift(arguments);
        var exprs = arguments;
        var f = function() {
            for (var i = 0; i < args.length; i ++)
                this.define(args[i], arguments[i]);
            var r;
            for (var i = 0; i < exprs.length; i++) {
                r = exprs[i].eval(this);
            }
            return r;
        };
        f.ctx = this.saveScope();
        return f;
    }"))

(define let
    (jsspform "function() {
        var argPairs = Array.shift(arguments);
        var exprs = arguments;
        var ps = [];
        var vs = [];
    
        for (var i = 0; i < argPairs.length; i ++) {
            ps.push(argPairs[i][0]);
            vs.push(argPairs[i][1]);
        }
    
        var lambdaSpform = this.resolve(new Symbol('lambda'));
    
        Array.unshift(exprs, ps);
        var fn = lambdaSpform.eval(this, exprs);
        var list = [fn].concat(vs)
    
        return list.eval(this);
    }"))

(define begin
    (jslambda "function() {
        return arguments[arguments.length - 1];
    }"))

(define + 
    (jslambda "function() { 
        var result = arguments[0];
        for (var i = 1; i < arguments.length; i ++) result += arguments[i];
        return result
    }"))

(define -
    (jslambda "function() {
        var result = arguments[0];
        for (var i = 1; i < arguments.length; i ++) result -= arguments[i];
        return result
    }"))

(define /
    (jslambda "function() {
        var result = arguments[0];
        for (var i = 1; i < arguments.length; i ++) result /= arguments[i];
        return result
    }"))

(define *
    (jslambda "function() {
        var result = arguments[0];
        for (var i = 1; i < arguments.length; i ++) result *= arguments[i];
        return result
    }"))

(define =
    (jslambda "function(a, b) {
        return (a == b) ? 1 : 0
    }"))

(define <
    (jslambda "function(a, b) {
        return (a < b) ? 1 : 0
    }"))

(define >
    (jslambda "function(a, b) {
        return (a > b) ? 1 : 0
    }"))

(define expt
    (jslambda "function(a, b) {
        return Math.pow(a, b)
    }"))

(define or
    (jslambda "function(a, b) {
        return (a || b) ? 1 : 0
    }"))

(define and
    (jslambda "function(a, b) {
        return (a && b) ? 1 : 0
    }"))

(define display
    (jslambda "function(a) {
        document.getElementById('log').appendChild(document.createTextNode(a + '\n'));
        return a;
    }"))