A general purpose JavaScript platform
Narwhal is a cross-platform, multi-interpreter, general purpose JavaScript platform. It aims to provide a solid foundation for building JavaScript applications, primarily outside the web browser. Narwhal includes a package manager, module system, and standard library for multiple JavaScript interpreters. Currently Narwhal’s Rhino support is the most complete, but other engines are available too.
Narwhal’s standard library conforms to the CommonJS standard. It is designed to work with multiple JavaScript interpreters, and to be easy to add support for new interpreters. Wherever possible, it is implemented in pure JavaScript to maximize reuse of code among engines.
Combined with Jack, a Rack-like JSGI compatible library, Narwhal provides a platform for creating server-side JavaScript web applications and frameworks such as Nitro.
Homepage:
Documentation
- Quick Start
- Packages
- How to Install Packages
- How to Build Packages
- Modules
- Virtual Environments / Seas
- How to Build Engines
- How Narwhal Works
Quick Start
Download Narwhal.
- download and extract the zip or tar archive, or
git clone git://github.com/280north/narwhal.git
Put Narwhal on your PATH
environment variable.
export PATH=$PATH:~/narwhal/bin
, orsource narwhal/bin/activate
Run narwhal
or js
(they are equivalent).
js narwhal/examples/hello
Look at the options for Narwhal.
js --help
And for Tusk, the package manager and virtual environment tool.
tusk help
My First Web Server
Create a project “hello-web”.
tusk init hello-web
cd hello-web
Enter your project as a “virtual environment” using activate
or sea
so that its libraries, binaries, and packages get automatically installed when you run Narwhal.
source bin/activate
or
bin/sea
Install some packages you will need, like Jack, the JSGI standard library for interoperable web services.
tusk install jack
Tusk gets downloaded and installed at “hello-web/packages/jack”.
Create your jackconfig.js
.
exports.app = function(env) {
var text = "Hello, Web!";
return {
status : 200,
headers : {
"Content-Type" : "text/plain",
"Content-Length" : String(text.length)
},
body : [text]
};
};
Run it!
jackup
jackup
looks for a file called jackconfig.js
in the current directory, or you can specify a path to a Jack application.
Open http://localhost:8080/ in your web browser.
Module System Basics
Narwhal “scripts” are CommonJS compatible modules, much like Python or Ruby modules. You do not have to use module pattern boilerplate; every module has its own local scope. You can get the exports object of another module by calling require
.
var FS = require("file");
FS.isFile("foo.txt");
Module identifiers for require
come in three flavors: “top-level”, “relative”, and “absolute”. In the above case, file
is a “top-level” identifier, so it will load any module called file.js
in the lib
directory of whichever package comes first in the load path. Relative identifiers have .
or ..
as their first term, and terms are delimited with /
. So, in the foo/bar
module, require('./baz')
will load foo/baz
. Absolute module identifiers should not be used directly, but are produced when you execute a program module outside the module path. The module is identified by its fully-qualified path, starting with /
.
You can export an object by assigning it to exports
.
exports.foo = function () {
return "Hello";
};
In a module, you also get a module
object that has module.id
and module.path
properties so you can inspect your own top-level module identifier, and the path of your own module file. You also get a require.main
property that tells you the top-level module identifier of the module that started the program.
if (require.main == module)
main();
var settings = require(require.main);
var FS = require("file");
var path = FS.path(module.path);
var indexHtml = path.resolve("./template/index.html").read();
Beyond the CommonJS specification, you also get the print
function and the system
module object for free. The print
function accepts variadic arguments and writes a single line containing the arguments delimited by spaces to standard output and flushes. The system
module can be explicitly required with require("system")
as is encouraged since it is necessary for CommonJS compliance. Do not use print
or system
in standard libraries.
Summary of Included Modules
system
:args
,env
,stdin
,stdout
,stderr
io
:ByteIO
(read
,write
,toByteString
,toString
),StringIO
(read
,write
,copy
,flush
,iterator
,forEach
,readLine
,readLines
,next
,print
,toString
,substring
,slice
,substr
),IO
(read
,write
,copy
,flush
,close
,isatty
),TextInputStream
(raw
,readLine
,next
,iterator
,forEach
,close
),TextOutputStream
(write
,writeLine
,writeLines
,print
,flush
,close
)file
:open
,read
,write
,copy
,link
,symlink
,rename
,move
,remove
,mkdir
,mkdirs
,rmdir
,rmtree
,touch
,chmod
,chown
,list
,listTree
,listDirectoryTree
,copyTree
,isAbsolute
,isRelative
,isDrive
,isReadable
,isWritable
,glob
,globPaths
,fnmatch
,match
,cwd
,cwdPath
,join
,split
,resolve
,relative
,absolute
,normal
,canonical
,root
,dirname
,basename
,extension
,path
,new Path
(to
,from
, …)os
:exit
,sleep
,popen
(wait
,stdin
,stdout
,stderr
,communicate
(status
,stdin
,stdout
,stderr
)),system
,command
,status
,enquote
binary
:Binary
(toArray
,toByteArray
,toByteString
,indexOf
,lastIndexOf
,valueOf
),ByteString
(length
,toString
,split
,slice
,substr
,substring
,toSource
),ByteArray
(toString
,pop
,push
,extendRight
,unshift
,extendLeft
,reverse
,slice
,splice
,split
,forEach
,every
,some
,map
,reduce
,reduceRight
,displace
,toSource
)assert
:AssertionError
,fail
,ok
,equal
,notEqual
,deepEqual
,notDeepEqual
,strictEqual
,notStrictEqual
,throws
,Assert
(pass
,error
,section
)test
:run
,Log
(flush
,pass
,fail
,error
,begin
,end
,report
,print
,section
,Assert
),Section
(print
)util
:operator
,no
,object
,array
,string
,apply
,copy
,deepCopy
,repr
,keys
,values
,items
,len
,has
,get
,set
,getset
,cut
,put
,first
,last
,update
,deepUpdate
,complete
,deepComplete
,remove
,range
,forEach
,forEachApply
,map
,mapApply
,every
,some
,all
,any
,reduce
,reduceRight
,zip
,transpose
,enumerate
,is
,eq
,ne
,lt
,gt
,le
,ge
,mul
,by
,compare
,sort
,sorted
,reverse
,reversed
,hash
,unique
,escape
,enquote
,expand
,trim
,trimBegin
,trimEnd
,padBegin
,padEnd
,splitName
,joinName
,lower
,upper
,camel
,title
http
:open
,read
sha
,sha256
,md5
,md4
,crc32
:hash
utf8
,base64
,base16
:encode
,decode
jsmin
:encode
jsonpath
:resolve
logger
:Logger
(add
,format
)args
:Parser
(parse
,option
, (_
,__
,name
,displayName
,getName
,getDisplayName
,action
,set
,push
,inc
,dec
,choices
,def
,validate
,input
,output
,number
,oct
,hex
,integer
,natural
,whole
,bool
,todo
,inverse
,help
,halt
,hidden
),group
(option
),def
,reset
,command
,arg
,args
,act
,action
,helpful
,usage
,help
,printHelp
,printUsage
,printCommands
,printOption
,printOptions
,error
,exit
,print
,check
),UsageError
,ConfigurationError
term
:Stream
(enable
,disable
,writeCode
,print
,printError
,write
,update
,moveTo
,moveBy
,home
,clear
,clearUp
,clearDown
,clearLine
,clearRight
,error
(print
,write
)),colors
,stream
uuid
:uuid
mime
:bestMatch
,parseMimeType
,parseMediaRange
,fitnessAndQualityParsed
,qualityParsed
,quality
html
:escapeHTML
,stripTags
ref-send
,promise
,events
:when
,defer
(resolve
,reject
,promise
),event-loop
:enqueue
printf
:printf
,fprintf
,sprintf
querystring
:unescape
,escape
,stringify
,parseQuery
sandbox
:Sandbox
loader
:Loader
(resolve
,resolvePkg
,find
,fetch
,load
,reload
,isLoaded
,hasChanged
,paths
,extensions
),resolve
,resolvePkg
packages
:order
,catalog
interpreter
:Context
(eval
,importScript
,importScripts
,Module
,Function
)zip
:unzip
,Unzip
(iterator
,forEach
,close
),Entry
(getName
,isDirectory
,open
,read
,copy
)