Compile-time expansion utility

This module serves as an example of parse_trans-based transforms, but might also be a useful utility in its own right. The transform searches for calls to the pseudo-function ct_expand:term(Expr), and then replaces the call site with the result of evaluating Expr at compile-time.

For example, the line

ct_expand:term(lists:sort([3,5,2,1,4]))

would be expanded at compile-time to [1,2,3,4,5].

ct_expand has now been extended to also evaluate calls to local functions. See examples/ct_expand_test.erl for some examples.

A debugging facility exists: passing the option {ct_expand_trace, Flags} as an option, or adding a compiler attribute -ct_expand_trace(Flags) will enable a form of call trace.