PPX Rewriters for Ocaml, written using Camlp5

This is a collection of PPX rewriters, re-implementing those based on ppxlib and other libraries, but instead based on Camlp5. Included is also a collection of support libraries for writing new PPX rewriters. Included are:

pa_assert: ppx_assert pa_ppx.deriving, pa_ppx.deriving_plugins (enum, eq, fold, iter, make, map, ord, sexp, show, yojson): ppx_deriving, plugins, ppx_sexp_conv, ppx_deriving_yojson pa_ppx.expect_test: ppx_expect_test pa_ppx.here: ppx_here pa_ppx.import: ppx_import pa_ppx.inline_test: ppx_inline_test

pa_ppx.undo_deriving: pa_ppx.deriving expands [@@deriving ...] into code; this rewriter undoes that. pa_ppx.unmatched_vala: expands to match-cases (support library for camlp5-based PPX rewriters) pa_ppx.hashrecons: support for writing AST rewriters that automatically fills in hash-consing boilerplate pa_dock: implements doc-comment extraction for camlp5 preprocessors

Many of the reimplementations in fact offer significant enhanced function, described in the pa_ppx documentation. In addition, there is an extensive test-suite, much of it slightly modified versions of the tests for the respective PPX rewriters.