The problem with reading synchronously from /dev/stdin is that you can get a
spurious EOF when the input buffer is empty, even if more content is coming. Now
STDIN is read from a loop, and only stops polling when all input has been read.
This fixes#70#85 and other errors related to parsing large files on STDIN.
For now the implication is that UglifyJS will not leak a function
expression's name in the surrounding scope (IE < 9 does that).
(ref. mishoo/UglifyJS#485)
This is useful while compressing generated code; for example compressing JS
compiled by CoffeeScript (assuming you got a source map):
uglifyjs2 --in-source-map generated.js.map \
--source-map uglified.js.map \
-o uglified.js
The above assumes you have a "generated.js.map" file which is the source
mapping between your CoffeeScript and the generated.js (compiled output from
CoffeeScript). The name of the input file is not present in this example;
it will be fetched from the source map (but it can be passed manually too).
The output will be in "uglified.js" and the output map "uglified.js.map"
will actually map to the original CoffeeScript code, rather than to
generated.js.
- a = a + x ==> a+=x
- joining consecutive var statements (hoisting is not always desirable)
- x == false ==> x == 0, x != true ==> x != 1
- x, x ==> x; x = exp(), x ==> x = exp()
- discarding useless break-s
- all symbols now have a `thedef` property which is a SymbolDef object,
instead of the `uniq` that we had before (pointing to the first occurrence
of the name as declaration).
- for undeclared symbols we still create a SymbolDef object in the toplevel
scope but mark it "undeclared"
- we can now call figure_out_scope after squeezing, which is useful in order
not to mangle names that were dropped by the squeezer
