lispyscript/lib/ls.js

/*
 *
LispyScript - Javascript using tree syntax!
This is the compiler written in javascipt
 *
*/

define(['require', 'exports', 'module', 'underscore'], function(require, exports, module, _) {

var _ = require('underscore');
var fs;
if (typeof window === "undefined")
  fs = require('fs');

String.prototype.repeat = function(num) {
    return new Array(num + 1).join(this);
};

exports.version = "0.2.9";
var banner = "// Generated by LispyScript v" + this.version + "\n",
    isWhitespace = /\s/,
    isFunction = /^function\b/,
    validName = /^[a-zA-Z_$][0-9a-zA-Z_$]*$/,
    noReturn = /^var\b|^set\b|^throw\b/,
    isHomoiconicExpr = /^#args-if\b|^#args-shift\b|^#args-second\b/,
    noSemiColon = false;
    indent = -4,
    keywords = {},
    macros = {},
    templates = {};
templates["var"] = _.template("var <%= rest %>");
templates["new"] = _.template("new <%= rest %>");
templates["set"] = _.template("<%= name %> = <%= value %>");
templates["function"] = _.template("function(<%= params %>) {\n<%= expressions %><%= indent %>}");
templates["try"] = _.template("(function() {\n<%= indent %>try {\n<%= trypart %>\n<%= indent %>} catch (e) {\n<%= indent %>return (<%= catchpart %>)(e);\n<%= indent %>}\n<%= indent %>})()");
templates["if"] = _.template("(<%= condition %> ?\n<%= indent %><%= trueexpr %> :\n<%= indent %><%= falseexpr %>)");
//templates["if"] = _.template("(function() {return <%= condition %> ?\n<%= indent %><%= trueexpr %> :\n<%= indent %><%= falseexpr %>;})()");
templates["get"] = _.template("<%= list %>[<%= key %>]");
templates["operator"] = _.template("(<%= loperand %> <%= operator %> <%= roperand %>)");
templates["str"] = _.template("[<%= elems %>].join('')");
templates["throw"] = _.template("(function(){throw <%= rest %>;})()");

var parse = function(code, filename) {
    code = "(" + code + ")";
    var length = code.length,
        pos = 1,
        lineno = 1;

    var parser = function() {
        var tree = [],
            token = "",
            isString = false,
            isSingleString = false,
            isJSArray = 0,
            isJSObject = 0,
            isListComplete = false,
            isComment = false,
            isRegex = false,
            isEscape = false;
        tree._line = lineno;
        tree._filename = filename;
        var handleToken = function() {
            if (token) {
                tree.push(token);
                token = "";
            }
        };
        while (pos < length) {
            var c = code.charAt(pos);
            pos++;
            if (c == "\n") {
                lineno++;
                if (isComment) isComment = false;
            }
            if (isComment) continue;
            if (isEscape) {
                isEscape = false;
                token += c;
                continue;
            }
            if (c == '"') {
                isString = !isString;
                token += c;
                continue;
            }
            if (isString) {
                if (c === "\n")
                    token += "\\n";
                else {
                    if (c === "\\") isEscape = true;
                    token += c;
                }
                continue;
            }
            if (c == "'") {
                isSingleString = !isSingleString;
                token += c;
                continue;
            }
            if (isSingleString) {
                token += c;
                continue;
            }
            if (c == '[') {
                isJSArray++;
                token += c;
                continue;
            }
            if (c == ']') {
                if (isJSArray === 0) handleError(4, tree._line, tree._filename);
                isJSArray--;
                token += c;
                continue;
            }
            if (isJSArray) {
                token += c;
                continue;
            }
            if (c == '{') {
                isJSObject++;
                token += c;
                continue;
            }
            if (c == '}') {
                if (isJSObject === 0) handleError(6, tree._line, tree._filename);
                isJSObject--;
                token += c;
                continue;
            }
            if (isJSObject) {
                token += c;
                continue;
            }
            if (c == ";") {
                isComment = true;
                continue;
            }
            // regex in function position with first char " " is a prob. Use \s instead.
            if (c === "/" && !(tree.length === 0 && token.length === 0 && isWhitespace.test(code.charAt(pos)))) {
                isRegex = !isRegex;
                token += c;
                continue;
            }
            if (isRegex) {
                if (c === "\\") isEscape = true;
                token += c;
                continue;
            }
            if (c == "(") {
                tree.push(parser());
                continue;
            }
            if (c == ")") {
                isListComplete = true;
                handleToken();
                break;
            }
            if (isWhitespace.test(c)) {
                handleToken();
                continue;
            }
            token += c;
        }
        if (isString) handleError(3, tree._line, tree._filename);
        if (isRegex) handleError(14, tree._line, tree._filename);
        if (isSingleString) handleError(3, tree._line, tree._filename);
        if (isJSArray > 0) handleError(5, tree._line, tree._filename);
        if (isJSObject > 0) handleError(7, tree._line, tree._filename);
        if (!isListComplete) handleError(8, tree._line, tree._filename);
        return tree;
    };
    var ret = parser();
    if (pos < length) handleError(10);
    return ret;
};

var handleExpressions = function(exprs) {
    indent += 4;
    var ret = "",
        l = exprs.length,
        indentstr = " ".repeat(indent);
    _.each(exprs, function(expr, i, exprs) {
        var exprName,
            tmp = "",
            r = "";
        if (_.isArray(expr)) {
            exprName = expr[0];
            if (exprName === "include")
                ret += handleExpression(expr);
            else
                tmp = handleExpression(expr);
        } else {
            tmp = expr;
        }
        if (i === l - 1 && indent) {
            if (!noReturn.test(exprName)) r = "return ";
        }
        if (tmp.length > 0) {
            var endline = noSemiColon ? "\n" : ";\n";
            noSemiColon = false;
            ret += indentstr + r + tmp + endline;
        }
    });
    indent -= 4;
    return ret;
};

var handleExpression = function(expr) {
    if (!expr) return "";
    var command = expr[0];
    if (macros[command]) {
        expr = macroExpand(expr);
        if (_.isArray(expr))
            return handleExpression(expr);
        else
            return expr;
    }
    if (_.isString(command)) {
        if (keywords[command])
            return keywords[command](expr);
        if (command.charAt(0) === ".") {
            return "(" + (_.isArray(expr[1]) ? handleExpression(expr[1]) : expr[1]) + ")" + command;
        }
    }
    handleSubExpressions(expr);
    var fName = expr[0];
    if (!fName) handleError(1, expr._line);
    if (isFunction.test(fName)) fName = "(" + fName + ")";
    return fName + "(" + expr.slice(1).join(",") + ")";
};

var handleSubExpressions = function(expr) {
    _.each(expr, function(value, i, t) {
        if (_.isArray(value)) t[i] = handleExpression(value);
    });
};

var macroExpand = function(tree) {
    var command = tree[0],
        template = macros[command]["template"],
        code = macros[command]["code"],
        replacements = {};
    for (var i = 0; i < template.length; i++) {
        if (template[i] == "rest...") {
            replacements["~rest..."] = tree.slice(i + 1);
        } else {
            if (tree.length === i + 1) {
                // we are here if any macro arg is not set
                handleError(12, tree._line, tree._filename, command);
            }
            replacements["~" + template[i]] = tree[i + 1];
        }
    }
    var replaceCode = function(source) {
        var ret = [];
        ret._line = tree._line;
        ret._filename = tree._filename;

        // Handle homoiconic expressions in macro
        var expr_name = source[0];
        if (isHomoiconicExpr.test(expr_name)) {
            var replarray = replacements["~" + source[1]];
            if (expr_name === "#args-shift") {
                if (!_.isArray(replarray)) handleError(13, tree._line, tree._filename, command);
                var argshift = replarray.shift();
                if (_.isUndefined(argshift)) handleError(12, tree._line, tree._filename, command);
                return argshift;
            }
            if (expr_name === "#args-second") {
                if (!_.isArray(replarray)) handleError(13, tree._line, tree._filename, command);
                var argsecond = replarray.splice(1, 1)[0];
                if (_.isUndefined(argsecond)) handleError(12, tree._line, tree._filename, command);
                return argsecond;
            }
            if (expr_name === "#args-if") {
                if (!_.isArray(replarray)) handleError(13, tree._line, tree._filename, command);
                if (replarray.length)
                    return replaceCode(source[2]);
                else if (source[3])
                    return replaceCode(source[3]);
                else
                    return;
            }
        }
        for (var i = 0; i < source.length; i++) {
            if (typeof source[i] == "object") {
                var replcode = replaceCode(source[i]);
                if (!_.isUndefined(replcode)) ret.push(replcode);
            } else {
                var token = source[i];
                var tokenbak = token;
                var isATSign = false;
                if (token.indexOf("@") >= 0) {
                    isATSign = true;
                    tokenbak = token.replace("@", "") ;
                }
                if (replacements[tokenbak]) {
                    var repl = replacements[tokenbak];
                    if (isATSign || tokenbak == "~rest...") {
                        for (var j = 0; j < repl.length; j++)
                            ret.push(repl[j]);
                    } else {
                        ret.push(repl);
                    }
                } else {
                    ret.push(token);
                }
            }
        }
        return ret;
    };
    return replaceCode(code);
};

var handleOperator = function(arr) {
    if (arr.length != 3)  handleError(0, arr._line);
    handleSubExpressions(arr);
    if (arr[0] == "=") arr[0] = "===";
    if (arr[0] == "!=") arr[0] = "!==";
    return templates["operator"]({operator: arr[0], loperand: arr[1], roperand: arr[2]});
};

keywords["var"] = function(arr) {
    if (!validName.test(arr[1])) handleError(9, arr._line, arr._filename);
    return templates["var"]({rest: keywords.set(arr)});
};

keywords["new"] = function(arr) {
    if (arr.length < 2) handleError(0, arr._line, arr._filename);
    return templates["new"]({ rest: handleExpression(arr.slice(1)) });
};


keywords["throw"] = function(arr) {
    if (arr.length != 2)  handleError(0, arr._line, arr._filename);
    return templates["throw"]({ rest: (typeof arr[1] == "object") ? handleExpression(arr[1]) : arr[1] });
};

keywords["set"] = function(arr) {
    if (arr.length < 3 || arr.length > 4) handleError(0, arr._line, arr._filename);
    if (arr.length == 4) {
    	arr[1] = ((typeof arr[2] == "object") ? handleExpression(arr[2]) : arr[2]) + "[" + arr[1] + "]";
    	arr[2] = arr[3];
    }
    return templates["set"]({
        name: arr[1],
        value: (typeof arr[2] == "object") ? handleExpression(arr[2]) : arr[2]});
};

keywords["function"] = function(arr) {
    if (arr.length < 2) handleError(0, arr._line, arr._filename);
    if (typeof arr[1] != "object") handleError(0, arr._line);
    return templates["function"]({
        params: arr[1].join(","),
        expressions: handleExpressions(arr.slice(2)),
        indent: " ".repeat(indent)});
};

keywords["try"] = function(arr) {
    if (arr.length < 3) handleError(0, arr._line, arr._filename);
    var c = arr.pop();
    return templates["try"]({
        trypart: handleExpressions(arr.slice(1)),
        catchpart: _.isArray(c) ? handleExpression(c) : c,
        indent: " ".repeat(indent)});
};

keywords["if"] = function(arr) {
    if (arr.length < 3 || arr.length > 4)  handleError(0, arr._line, arr._filename);
    indent += 4;
    handleSubExpressions(arr);
    var ret = templates["if"]({
        condition: arr[1],
        trueexpr: arr[2],
        falseexpr: arr[3] || "undefined",
        indent: " ".repeat(indent)});
    indent -= 4;
    return ret;
};

keywords["get"] = function(arr) {
    if (arr.length != 3) handleError(0, arr._line, arr._filename);
    handleSubExpressions(arr);
    return templates["get"]({key: arr[1], list: arr[2]});
};

keywords["str"] = function(arr) {
    if (arr.length < 2) handleError(0, arr._line, arr._filename);
    handleSubExpressions(arr);
    return templates["str"]({elems: arr.slice(1).join(",")});
};

var includeFile = (function () {
	var included = [];
	return function(filename) {
	    var found = _.find(included, function(f) {return f === filename;});
	    if (found) return "";
	    included.push(filename);
	    var code = fs.readFileSync(filename);
	    var tree = parse(code, filename);
        return handleExpressions(tree);
    };
})();

keywords["include"] = function(arr) {
    if (arr.length != 2)  handleError(0, arr._line, arr._filename);
    indent -= 4;
    var filename = arr[1];
    if (typeof filename === "string")
        filename = filename.replace(/["']/g, "");
    try {
    	filename = fs.realpathSync(filename);
    } catch (err) {
    	try {
    		filename = fs.realpathSync(__dirname + "/../includes/" + filename);
    	} catch (err) {
            handleError(11, arr._line, arr._filename);
        }
    }
    var ret = includeFile(filename);
    indent += 4;
    return ret;
};

keywords["javascript"] = function(arr) {
    if (arr.length != 2)  handleError(0, arr._line, arr._filename);
    noSemiColon = true;
    return arr[1].replace(/"/g, '');
}

keywords["macro"] = function(arr) {
    if (arr.length != 4)  handleError(0, arr._line, arr._filename);
    macros[arr[1]] = {template: arr[2], code: arr[3]};
    return "";
};



keywords["+"] = handleOperator;

keywords["-"] = handleOperator;

keywords["*"] = handleOperator;

keywords["/"] = handleOperator;

keywords["%"] = handleOperator;

keywords["="] = handleOperator;

keywords["!="] = handleOperator;

keywords[">"] = handleOperator;

keywords[">="] = handleOperator;

keywords["<"] = handleOperator;

keywords["<="] = handleOperator;

keywords["||"] = handleOperator;

keywords["&&"] = handleOperator;

keywords["!"] = function(arr) {
    if (arr.length != 2)  handleError(0, arr._line, arr._filename);
    handleSubExpressions(arr);
    return "(!" + arr[1] + ")";
};

var handleError = function(no, line, filename, extra) {
    throw new Error(errors[no] + 
           ((extra) ? " - " + extra : "") + 
           ((line) ? "\nLine no " + line : "") + 
           ((filename) ? "\nFile " + filename : ""));
};

errors = [];
errors[0] = "Syntax Error";
errors[1] = "Empty statement";
errors[2] = "Invalid characters in function name";
errors[3] = "End of File encountered, unterminated string";
errors[4] = "Closing square bracket, without an opening square bracket";
errors[5] = "End of File encountered, unterminated array";
errors[6] = "Closing curly brace, without an opening curly brace";
errors[7] = "End of File encountered, unterminated javascript object '}'";
errors[8] = "End of File encountered, unterminated parenthesis";
errors[9] = "Invalid character in var name";
errors[10] = "Extra chars at end of file. Maybe an extra ')'.";
errors[11] = "Cannot Open include File";
errors[12] = "Invalid no of arguments to "
errors[13] = "Invalid Argument type to "
errors[14] = "End of File encountered, unterminated regular expression";

exports._compile = function(code, filename) {
  var tree = parse(code, filename);
  return banner + handleExpressions(tree);
};

});