::
_____ _ _____ __ __ _____ _______
/ ____| | |_ _| \/ |_ _|__ __|
| (___ | | | | | \ / | | | | |
\___ \| | | | | |\/| | | | | |
____) | |____ _| |_| | | |_| |_ | |
|_____/|______|_____|_| |_|_____| |_|
SlimIt is a JavaScript minifier written in Python.
It compiles JavaScript into more compact code so that it downloads
and runs faster.
SlimIt also provides a library that includes a JavaScript parser,
lexer, pretty printer and a tree visitor.
http://slimit.readthedocs.org/ <http://slimit.readthedocs.org/>_
::
$ [sudo] pip install slimit
Or the bleeding edge version from the git master branch:
::
$ [sudo] pip install git+https://github.com/rspivak/slimit.git#egg=slimit
There is also an official DEB package available at
http://packages.debian.org/sid/slimit <http://packages.debian.org/sid/slimit>_
From the command line:
::
$ slimit -h
Usage: slimit [options] [input file]
If no input file is provided STDIN is used by default.
Minified JavaScript code is printed to STDOUT.
Options:
-h, --help show this help message and exit
-m, --mangle mangle names
-t, --mangle-toplevel
mangle top level scope (defaults to False)
$ cat test.js
var foo = function( obj ) {
for ( var name in obj ) {
return false;
}
return true;
};
$
$ slimit --mangle < test.js
var foo=function(a){for(var b in a)return false;return true;};
Or using library API:
from slimit import minify text = """ ... var foo = function( obj ) { ... for ( var name in obj ) { ... return false; ... } ... return true; ... }; ... """ print minify(text, mangle=True, mangle_toplevel=True) var a=function(a){for(var b in a)return false;return true;};
from slimit.parser import Parser from slimit.visitors import nodevisitor from slimit import ast
parser = Parser() tree = parser.parse('for(var i=0; i<10; i++) {var x=5+i;}') for node in nodevisitor.visit(tree): ... if isinstance(node, ast.Identifier) and node.value == 'i': ... node.value = 'hello' ... print tree.to_ecma() # print awesome javascript :) for (var hello = 0; hello < 10; hello++) { var x = 5 + hello; }
from slimit.parser import Parser from slimit.visitors.nodevisitor import ASTVisitor
text = """ ... var x = { ... "key1": "value1", ... "key2": "value2" ... }; ... """
class MyVisitor(ASTVisitor): ... def visit_Object(self, node): ... """Visit object literal.""" ... for prop in node: ... left, right = prop.left, prop.right ... print 'Property key=%s, value=%s' % (left.value, right.value) ... # visit all children in turn ... self.visit(prop) ...
parser = Parser() tree = parser.parse(text) visitor = MyVisitor() visitor.visit(tree) Property key="key1", value="value1" Property key="key2", value="value2"
from slimit.lexer import Lexer lexer = Lexer() lexer.input('a = 1;') for token in lexer: ... print token ... LexToken(ID,'a',1,0) LexToken(EQ,'=',1,2) LexToken(NUMBER,'1',1,4) LexToken(SEMI,';',1,5)
You can get one token at a time using token method:
lexer.input('a = 1;') while True: ... token = lexer.token() ... if not token: ... break ... print token ... LexToken(ID,'a',1,0) LexToken(EQ,'=',1,2) LexToken(NUMBER,'1',1,4) LexToken(SEMI,';',1,5)
LexToken instance has different attributes:
lexer.input('a = 1;') token = lexer.token() token.type, token.value, token.lineno, token.lexpos ('ID', 'a', 1, 0)
SAM - JQuery size after minification in bytes (the smaller number the better)
+-------------------------------+------------+------------+------------+ | Original jQuery 1.6.1 (bytes) | SlimIt SAM | rJSmin SAM | jsmin SAM | +===============================+============+============+============+ | 234,995 | 94,290 | 134,215 | 134,819 | +-------------------------------+------------+------------+------------+
when doing name mangling handle cases with 'eval' and 'with'
foo["bar"] ==> foo.bar
consecutive declarations: var a = 10; var b = 20; ==> var a=10,b=20;
reduce simple constant expressions if the result takes less space: 1 +2 * 3 ==> 7
IF statement optimizations
remove unreachable code that follows a return, throw, break or continue statement, except function/variable declarations
parsing speed improvements
PLY <http://www.dabeaz.com/ply/>_jslex <https://bitbucket.org/ned/jslex>_pycparser <http://code.google.com/p/pycparser/>_rkelly <https://github.com/tenderlove/rkelly>_UglifyJS <https://github.com/mishoo/UglifyJS>_pyjsparser <http://bitbucket.org/mvantellingen/pyjsparser>_The MIT License (MIT)
FAQs
SlimIt - JavaScript minifier
We found that slimit demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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