Compile PHP 7 to PHP 5.6

[Jesse Schalken <me@xxxxxxxxxxxxxxxxx>]

Is anyone aware of a tool for compiling PHP 7 code to PHP 5.6 code (or
earlier)? Many of the features added from 5.3 to 7.0 appear to be syntactic
conveniences which could be "desugared" or compiled to equivalent code for
earlier PHP versions.

I'm thinking on similar lines as Babel enables ecmascript 6 to be compiled
to ecmascript 5.

Thanks