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nodejs/lib/repl.js

488 lines
15 KiB
JavaScript

// A repl library that you can include in your own code to get a runtime
// interface to your program.
//
// var repl = require("/repl.js");
// repl.start("prompt> "); // start repl on stdin
// net.createServer(function (socket) { // listen for unix socket connections and start repl on them
// repl.start("node via Unix socket> ", socket);
// }).listen("/tmp/node-repl-sock");
// net.createServer(function (socket) { // listen for TCP socket connections and start repl on them
// repl.start("node via TCP socket> ", socket);
// }).listen(5001);
// repl.start("node > ").context.foo = "stdin is fun"; // expose foo to repl context
var util = require('util');
var Script = process.binding('evals').Script;
var evalcx = Script.runInContext;
var path = require("path");
var fs = require("fs");
var rl = require('readline');
var context;
var disableColors = process.env.NODE_DISABLE_COLORS ? true : false;
// hack for require.resolve("./relative") to work properly.
module.filename = process.cwd() + "/repl";
function resetContext() {
context = Script.createContext();
for (var i in global) context[i] = global[i];
context.module = module;
context.require = require;
}
// Can overridden with custom print functions, such as `probe` or `eyes.js`
exports.writer = util.inspect;
function REPLServer(prompt, stream) {
var self = this;
if (!context) resetContext();
if (!exports.repl) exports.repl = this;
self.context = context;
self.buffered_cmd = '';
self.stream = stream || process.openStdin();
self.prompt = prompt || "> ";
var rli = self.rli = rl.createInterface(self.stream, function (text) {
return self.complete(text);
});
this.commands = {};
defineDefaultCommands(this);
if (rli.enabled && !disableColors) {
// Turn on ANSI coloring.
exports.writer = function(obj, showHidden, depth) {
return util.inspect(obj, showHidden, depth, true);
};
}
rli.setPrompt(self.prompt);
rli.on("SIGINT", function () {
if (self.buffered_cmd && self.buffered_cmd.length > 0) {
rli.write("\n");
self.buffered_cmd = '';
self.displayPrompt();
} else {
rli.close();
}
});
self.stream.addListener("data", function (chunk) {
rli.write(chunk);
});
rli.addListener('line', function (cmd) {
cmd = trimWhitespace(cmd);
// Check to see if a REPL keyword was used. If it returns true,
// display next prompt and return.
if (cmd && cmd.charAt(0) === '.') {
var matches = cmd.match(/^(\.[^\s]+)\s*(.*)$/);
var keyword = matches && matches[1];
var rest = matches && matches[2];
if (self.parseREPLKeyword(keyword, rest) === true) return;
}
// The catchall for errors
try {
self.buffered_cmd += cmd;
// This try is for determining if the command is complete, or should
// continue onto the next line.
try {
// Use evalcx to supply the global context
var ret = evalcx(self.buffered_cmd, context, "repl");
if (ret !== undefined) {
context._ = ret;
self.stream.write(exports.writer(ret) + "\n");
}
self.buffered_cmd = '';
} catch (e) {
// instanceof doesn't work across context switches.
if (!(e && e.constructor && e.constructor.name === "SyntaxError")) {
throw e;
// It could also be an error from JSON.parse
} else if(e && e.stack
&& e.stack.match('Unexpected token ILLEGAL')
&& e.stack.match(/Object.parse \(native\)/)) {
throw e;
}
}
} catch (e) {
// On error: Print the error and clear the buffer
if (e.stack) {
self.stream.write(e.stack + "\n");
} else {
self.stream.write(e.toString() + "\n");
}
self.buffered_cmd = '';
}
self.displayPrompt();
});
rli.addListener('close', function () {
self.stream.destroy();
});
self.displayPrompt();
}
exports.REPLServer = REPLServer;
// prompt is a string to print on each line for the prompt,
// source is a stream to use for I/O, defaulting to stdin/stdout.
exports.start = function (prompt, source) {
return new REPLServer(prompt, source);
};
REPLServer.prototype.displayPrompt = function () {
this.rli.setPrompt(this.buffered_cmd.length ? '... ' : this.prompt);
this.rli.prompt();
};
// read a line from the stream, then eval it
REPLServer.prototype.readline = function (cmd) {
};
/**
* Provide a list of completions for the given leading text. This is
* given to the readline interface for handling tab completion.
*
* @param {line} The text (preceding the cursor) to complete
* @returns {Array} Two elements: (1) an array of completions; and
* (2) the leading text completed.
*
* Example:
* complete('var foo = util.')
* -> [['util.print', 'util.debug', 'util.log', 'util.inspect', 'util.pump'],
* 'util.' ]
*
* Warning: This eval's code like "foo.bar.baz", so it will run property
* getter code.
*/
REPLServer.prototype.complete = function (line) {
var completions,
completionGroups = [], // list of completion lists, one for each inheritance "level"
completeOn,
match, filter, i, j, group, c;
// REPL commands (e.g. ".break").
var match = null;
match = line.match(/^\s*(\.\w*)$/);
if (match) {
completionGroups.push(Object.keys(this.commands));
completeOn = match[1];
if (match[1].length > 1) {
filter = match[1];
}
}
// require('...<Tab>')
else if (match = line.match(/\brequire\s*\(['"](([\w\.\/-]+\/)?([\w\.\/-]*))/)) {
//TODO: suggest require.exts be exposed to be introspec registered extensions?
//TODO: suggest include the '.' in exts in internal repr: parity with `path.extname`.
var exts = [".js", ".node"];
var indexRe = new RegExp('^index(' + exts.map(regexpEscape).join('|') + ')$');
completeOn = match[1];
var subdir = match[2] || "";
var filter = match[1];
var dir, files, f, name, base, ext, abs, subfiles, s;
group = [];
for (i = 0; i < require.paths.length; i++) {
dir = require.paths[i];
if (subdir && subdir[0] === '/') {
dir = subdir;
} else if (subdir) {
dir = path.join(dir, subdir);
}
try {
files = fs.readdirSync(dir);
} catch (e) {
continue;
}
for (f = 0; f < files.length; f++) {
name = files[f];
ext = path.extname(name);
base = name.slice(0, -ext.length);
if (base.match(/-\d+\.\d+(\.\d+)?/) || name === ".npm") {
// Exclude versioned names that 'npm' installs.
continue;
}
if (exts.indexOf(ext) !== -1) {
if (!subdir || base !== "index") {
group.push(subdir + base);
}
} else {
abs = path.join(dir, name);
try {
if (fs.statSync(abs).isDirectory()) {
group.push(subdir + name + '/');
subfiles = fs.readdirSync(abs);
for (s = 0; s < subfiles.length; s++) {
if (indexRe.test(subfiles[s])) {
group.push(subdir + name);
}
}
}
} catch(e) {}
}
}
}
if (group.length) {
completionGroups.push(group);
}
if (!subdir) {
// Kind of lame that this needs to be updated manually.
// Intentionally excluding moved modules: posix, utils.
var builtinLibs = ['assert', 'buffer', 'child_process', 'crypto', 'dgram',
'dns', 'events', 'file', 'freelist', 'fs', 'http', 'net', 'path',
'querystring', 'readline', 'repl', 'string_decoder', 'util', 'tcp', 'url'];
completionGroups.push(builtinLibs);
}
}
// Handle variable member lookup.
// We support simple chained expressions like the following (no function
// calls, etc.). That is for simplicity and also because we *eval* that
// leading expression so for safety (see WARNING above) don't want to
// eval function calls.
//
// foo.bar<|> # completions for 'foo' with filter 'bar'
// spam.eggs.<|> # completions for 'spam.eggs' with filter ''
// foo<|> # all scope vars with filter 'foo'
// foo.<|> # completions for 'foo' with filter ''
else if (line.length === 0 || line[line.length-1].match(/\w|\.|\$/)) {
var simpleExpressionPat = /(([a-zA-Z_$](?:\w|\$)*)\.)*([a-zA-Z_$](?:\w|\$)*)\.?$/;
match = simpleExpressionPat.exec(line);
if (line.length === 0 || match) {
var expr;
completeOn = (match ? match[0] : "");
if (line.length === 0) {
filter = "";
expr = "";
} else if (line[line.length-1] === '.') {
filter = "";
expr = match[0].slice(0, match[0].length-1);
} else {
var bits = match[0].split('.');
filter = bits.pop();
expr = bits.join('.');
}
//console.log("expression completion: completeOn='"+completeOn+"' expr='"+expr+"'");
// Resolve expr and get its completions.
var obj, memberGroups = [];
if (!expr) {
completionGroups.push(Object.getOwnPropertyNames(this.context));
// Global object properties
// (http://www.ecma-international.org/publications/standards/Ecma-262.htm)
completionGroups.push(["NaN", "Infinity", "undefined",
"eval", "parseInt", "parseFloat", "isNaN", "isFinite", "decodeURI",
"decodeURIComponent", "encodeURI", "encodeURIComponent",
"Object", "Function", "Array", "String", "Boolean", "Number",
"Date", "RegExp", "Error", "EvalError", "RangeError",
"ReferenceError", "SyntaxError", "TypeError", "URIError",
"Math", "JSON"]);
// Common keywords. Exclude for completion on the empty string, b/c
// they just get in the way.
if (filter) {
completionGroups.push(["break", "case", "catch", "const",
"continue", "debugger", "default", "delete", "do", "else", "export",
"false", "finally", "for", "function", "if", "import", "in",
"instanceof", "let", "new", "null", "return", "switch", "this",
"throw", "true", "try", "typeof", "undefined", "var", "void",
"while", "with", "yield"]);
}
} else {
try {
obj = evalcx(expr, this.context, "repl");
} catch (e) {
//console.log("completion eval error, expr='"+expr+"': "+e);
}
if (obj != null) {
if (typeof obj === "object" || typeof obj === "function") {
memberGroups.push(Object.getOwnPropertyNames(obj));
}
// works for non-objects
var p = obj.constructor ? obj.constructor.prototype : null;
try {
var sentinel = 5;
while (p !== null) {
memberGroups.push(Object.getOwnPropertyNames(p));
p = Object.getPrototypeOf(p);
// Circular refs possible? Let's guard against that.
sentinel--;
if (sentinel <= 0) {
break;
}
}
} catch (e) {
//console.log("completion error walking prototype chain:" + e);
}
}
if (memberGroups.length) {
for (i = 0; i < memberGroups.length; i++) {
completionGroups.push(memberGroups[i].map(function(member) {
return expr + '.' + member;
}));
}
if (filter) {
filter = expr + '.' + filter;
}
}
}
}
}
// Filter, sort (within each group), uniq and merge the completion groups.
if (completionGroups.length && filter) {
var newCompletionGroups = [];
for (i = 0; i < completionGroups.length; i++) {
group = completionGroups[i].filter(function(elem) {
return elem.indexOf(filter) == 0;
});
if (group.length) {
newCompletionGroups.push(group);
}
}
completionGroups = newCompletionGroups;
}
if (completionGroups.length) {
var uniq = {}; // unique completions across all groups
completions = [];
// Completion group 0 is the "closest" (least far up the inheritance chain)
// so we put its completions last: to be closest in the REPL.
for (i = completionGroups.length - 1; i >= 0; i--) {
group = completionGroups[i];
group.sort();
for (var j = 0; j < group.length; j++) {
c = group[j];
if (!uniq.hasOwnProperty(c)) {
completions.push(c);
uniq[c] = true;
}
}
completions.push(""); // separator btwn groups
}
while (completions.length && completions[completions.length-1] === "") {
completions.pop();
}
}
return [completions || [], completeOn];
};
/**
* 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
*/
REPLServer.prototype.parseREPLKeyword = function (keyword, rest) {
var cmd = this.commands[keyword];
if (cmd) {
cmd.action.call(this, rest);
return true;
}
return false;
};
REPLServer.prototype.defineCommand = function(keyword, cmd) {
if (typeof cmd === 'function') cmd = {action: cmd};
else if (typeof cmd.action !== 'function') {
throw new Error('bad argument, action must be a function');
}
this.commands['.' + keyword] = cmd;
};
function defineDefaultCommands(repl) {
// TODO remove me after 0.3.x
repl.defineCommand('break', {
help: 'Sometimes you get stuck, this gets you out',
action: function() {
this.buffered_cmd = '';
this.displayPrompt();
}
});
repl.defineCommand('clear', {
help: 'Break, and also clear the local context',
action: function() {
this.stream.write("Clearing context...\n");
this.buffered_cmd = '';
resetContext();
this.displayPrompt();
}
});
repl.defineCommand('exit', {
help: 'Exit the repl',
action: function() {
this.rli.close();
}
});
repl.defineCommand('help', {
help: 'Show repl options',
action: function() {
var self = this;
Object.keys(this.commands).sort().forEach(function(name) {
var cmd = self.commands[name];
self.stream.write(name + "\t" + (cmd.help || '') + "\n");
});
this.displayPrompt();
}
});
}
function trimWhitespace (cmd) {
var trimmer = /^\s*(.+)\s*$/m,
matches = trimmer.exec(cmd);
if (matches && matches.length === 2) {
return matches[1];
}
}
function regexpEscape(s) {
return s.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
}
/**
* Converts commands that use var and function <name>() to use the
* local exports.context when evaled. This provides a local context
* on the REPL.
*
* @param {String} cmd The cmd to convert
* @returns {String} The converted command
*/
REPLServer.prototype.convertToContext = function (cmd) {
var self = this, matches,
scopeVar = /^\s*var\s*([_\w\$]+)(.*)$/m,
scopeFunc = /^\s*function\s*([_\w\$]+)/;
// Replaces: var foo = "bar"; with: self.context.foo = bar;
matches = scopeVar.exec(cmd);
if (matches && matches.length === 3) {
return "self.context." + matches[1] + matches[2];
}
// Replaces: function foo() {}; with: foo = function foo() {};
matches = scopeFunc.exec(self.buffered_cmd);
if (matches && matches.length === 2) {
return matches[1] + " = " + self.buffered_cmd;
}
return cmd;
};