154 строки
3.7 KiB
JavaScript
154 строки
3.7 KiB
JavaScript
// A repl library that you can include in your own code to get a runtime
|
|
// interface to your program. Just require("/repl.js").
|
|
|
|
var sys = require('sys');
|
|
|
|
var buffered_cmd = '';
|
|
var trimmer = /^\s*(.+)\s*$/m;
|
|
var scopedVar = /^\s*var\s*([_\w\$]+)(.*)$/m;
|
|
var scopeFunc = /^\s*function\s*([_\w\$]+)/;
|
|
|
|
exports.scope = {};
|
|
exports.prompt = "node> ";
|
|
// Can overridden with custom print functions, such as `probe` or `eyes.js`
|
|
exports.writer = sys.p;
|
|
|
|
var stdin;
|
|
|
|
exports.start = function (prompt) {
|
|
if (prompt !== undefined) {
|
|
exports.prompt = prompt;
|
|
}
|
|
|
|
stdin = process.openStdin();
|
|
stdin.setEncoding('utf8');
|
|
stdin.addListener("data", readline);
|
|
displayPrompt();
|
|
}
|
|
|
|
/**
|
|
* The main REPL function. This is called everytime the user enters
|
|
* data on the command line.
|
|
*/
|
|
function readline (cmd) {
|
|
cmd = trimWhitespace(cmd);
|
|
|
|
// Check to see if a REPL keyword was used. If it returns true,
|
|
// display next prompt and return.
|
|
if (parseREPLKeyword(cmd) === true) {
|
|
return;
|
|
}
|
|
|
|
// The catchall for errors
|
|
try {
|
|
buffered_cmd += cmd;
|
|
// This try is for determining if the command is complete, or should
|
|
// continue onto the next line.
|
|
try {
|
|
buffered_cmd = convertToScope(buffered_cmd);
|
|
|
|
// Scope the readline with exports.scope to provide "local" vars
|
|
with (exports.scope) {
|
|
var ret = eval(buffered_cmd);
|
|
if (ret !== undefined) {
|
|
exports.scope['_'] = ret;
|
|
exports.writer(ret);
|
|
}
|
|
}
|
|
|
|
buffered_cmd = '';
|
|
} catch (e) {
|
|
if (!(e instanceof SyntaxError)) throw e;
|
|
}
|
|
} catch (e) {
|
|
// On error: Print the error and clear the buffer
|
|
if (e.stack) {
|
|
sys.puts(e.stack);
|
|
} else {
|
|
sys.puts(e.toString());
|
|
}
|
|
buffered_cmd = '';
|
|
}
|
|
|
|
displayPrompt();
|
|
}
|
|
|
|
|
|
/**
|
|
* Used to display the prompt.
|
|
*/
|
|
function displayPrompt () {
|
|
sys.print(buffered_cmd.length ? '... ' : exports.prompt);
|
|
}
|
|
|
|
/**
|
|
* Used to parse and execute the Node REPL commands.
|
|
*
|
|
* @param {cmd} cmd The command entered to check
|
|
* @returns {Boolean} If true it means don't continue parsing the command
|
|
*/
|
|
function parseREPLKeyword (cmd) {
|
|
switch (cmd) {
|
|
case ".break":
|
|
buffered_cmd = '';
|
|
displayPrompt();
|
|
return true;
|
|
case ".clear":
|
|
sys.puts("Clearing Scope...");
|
|
buffered_cmd = '';
|
|
exports.scope = {};
|
|
displayPrompt();
|
|
return true;
|
|
case ".exit":
|
|
stdin.close();
|
|
return true;
|
|
case ".help":
|
|
sys.puts(".break\tSometimes you get stuck in a place you can't get out... This will get you out.");
|
|
sys.puts(".clear\tBreak, and also clear the local scope.");
|
|
sys.puts(".exit\tExit the prompt");
|
|
sys.puts(".help\tShow repl options");
|
|
displayPrompt();
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Trims Whitespace from a line.
|
|
*
|
|
* @param {String} cmd The string to trim the whitespace from
|
|
* @returns {String} The trimmed string
|
|
*/
|
|
function trimWhitespace (cmd) {
|
|
var matches = trimmer.exec(cmd);
|
|
if (matches && matches.length == 2) {
|
|
return matches[1];
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Converts commands that use var and function <name>() to use the
|
|
* local exports.scope when evaled. This provides a local scope
|
|
* on the REPL.
|
|
*
|
|
* @param {String} cmd The cmd to convert
|
|
* @returns {String} The converted command
|
|
*/
|
|
function convertToScope (cmd) {
|
|
var matches;
|
|
|
|
// Replaces: var foo = "bar"; with: exports.scope.foo = bar;
|
|
matches = scopedVar.exec(cmd);
|
|
if (matches && matches.length == 3) {
|
|
return "exports.scope." + matches[1] + matches[2];
|
|
}
|
|
|
|
// Replaces: function foo() {}; with: foo = function foo() {};
|
|
matches = scopeFunc.exec(buffered_cmd);
|
|
if (matches && matches.length == 2) {
|
|
return matches[1] + " = " + buffered_cmd;
|
|
}
|
|
|
|
return cmd;
|
|
}
|