javascript_routes/bin/jsmin.rb

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2008-04-17 11:47:13 +02:00
#!/usr/bin/ruby
# jsmin.rb 2007-05-22
# Author: Uladzislau Latynski
# This work is a translation from C to Ruby of jsmin.c published by
# Douglas Crockford. Permission is hereby granted to use the Ruby
# version under the same conditions as the jsmin.c on which it is
# based.
#
# /* jsmin.c
# 2003-04-21
#
# Copyright (c) 2002 Douglas Crockford (www.crockford.com)
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
# of the Software, and to permit persons to whom the Software is furnished to do
# so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# The Software shall be used for Good, not Evil.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
class JSMin
EOF = -1
def initialize(input, output)
@input, @output = input, output
@theA, @theB = '', ''
end
# isAlphanum -- return true if the character is a letter, digit, underscore,
# dollar sign, or non-ASCII character
def isAlphanum(c)
return false if !c || c == EOF
return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
(c >= 'A' && c <= 'Z') || c == '_' || c == '$' ||
c == '\\' || c[0] > 126)
end
# get -- return the next character from stdin. Watch out for lookahead. If
# the character is a control character, translate it to a space or linefeed.
def get()
c = @input.getc
return EOF if(!c)
c = c.chr
return c if (c >= " " || c == "\n" || c.unpack("c") == EOF)
return "\n" if (c == "\r")
return " "
end
# Get the next character without getting it.
def peek()
lookaheadChar = @input.getc
@input.ungetc(lookaheadChar)
return lookaheadChar.chr
end
# mynext -- get the next character, excluding comments.
# peek() is used to see if a '/' is followed by a '/' or '*'.
def mynext()
c = get
if (c == "/")
if(peek == "/")
while(true)
c = get
if (c <= "\n")
return c
end
end
end
if(peek == "*")
get
while(true)
case get
when "*"
if (peek == "/")
get
return " "
end
when EOF
raise "Unterminated comment"
end
end
end
end
return c
end
# action -- do something! What you do is determined by the argument: 1
# Output A. Copy B to A. Get the next B. 2 Copy B to A. Get the next B.
# (Delete A). 3 Get the next B. (Delete B). action treats a string as a
# single character. Wow! action recognizes a regular expression if it is
# preceded by ( or , or =.
def action(a)
if(a==1)
@output.write @theA
end
if(a==1 || a==2)
@theA = @theB
if (@theA == "\'" || @theA == "\"")
while (true)
@output.write @theA
@theA = get
break if (@theA == @theB)
raise "Unterminated string literal" if (@theA <= "\n")
if (@theA == "\\")
@output.write @theA
@theA = get
end
end
end
end
if(a==1 || a==2 || a==3)
@theB = mynext
if (@theB == "/" && (@theA == "(" || @theA == "," || @theA == "=" ||
@theA == ":" || @theA == "[" || @theA == "!" ||
@theA == "&" || @theA == "|" || @theA == "?" ||
@theA == "{" || @theA == "}" || @theA == ";" ||
@theA == "\n"))
@output.write @theA
@output.write @theB
while (true)
@theA = get
if (@theA == "/")
break
elsif (@theA == "\\")
@output.write @theA
@theA = get
elsif (@theA <= "\n")
raise "Unterminated RegExp Literal"
end
@output.write @theA
end
@theB = mynext
end
end
end
# jsmin -- Copy the input to the output, deleting the characters which are
# insignificant to JavaScript. Comments will be removed. Tabs will be
# replaced with spaces. Carriage returns will be replaced with linefeeds.
# Most spaces and linefeeds will be removed.
def jsmin
@theA = "\n"
action(3)
while (@theA != EOF)
case @theA
when " "
if (isAlphanum(@theB))
action(1)
else
action(2)
end
when "\n"
case (@theB)
when "{","[","(","+","-"
action(1)
when " "
action(3)
else
if (isAlphanum(@theB))
action(1)
else
action(2)
end
end
else
case (@theB)
when " "
if (isAlphanum(@theA))
action(1)
else
action(3)
end
when "\n"
case (@theA)
when "}","]",")","+","-","\"","\\", "'", '"'
action(1)
else
if (isAlphanum(@theA))
action(1)
else
action(3)
end
end
else
action(1)
end
end
end
end
end
JSMin.new($stdin, $stdout).jsmin if __FILE__ == $0