Lots of cleanup

* Remove some improperly applied dependencies
* More README details
* Use the 4.06 AST from OMP and ppx_tools_versioned
* Add repl, examples and test targets for make
* Simplify how jbuilder builds examples

CHANGES.md

@@ -1,3 +1,9 @@
+# vNext
+
+* Use 4.06 AST from ocaml-migrate-parsetree and ppx\_tools\_versioned
+* Add `make repl` target to automatically compile + load the source tree's ppx
+  into a custom utop session
+
 # v0.3.0
 
 * Use ocaml-migrate-parsetree

Makefile

@@ -1,5 +1,16 @@
+.PHONY: all clean examples repl test
+
 all:
-	jbuilder build
+	jbuilder build --dev
 
 clean:
-	rm -rf _build/ *.install
+	jbuilder clean
+
+examples:
+	jbuilder build @example --dev
+
+repl:
+	jbuilder utop src -- -require ppx_defer
+
+test: examples
+	jbuilder exec examples/ic.exe

README.md

@@ -10,6 +10,21 @@ Thanks to Drup for guidance in figuring out ppx details!
 
 ## Using ppx_defer
 
+As a simple example this code
+```ocaml
+let () =
+  [%defer print_endline "world"];
+  print_endline "Hello"
+```
+will print
+```
+Hello
+world
+```
+as `print_endline "world"` was deferred until after `print_endline "Hello"`.
+
+A more common use case would be closing an external resource at the end of the
+current expression.
 ```ocaml
 let () =
   let ic = open_in_bin "some_file" in
@@ -18,5 +33,12 @@ let () =
   let bytes = really_input_string ic length in
   print_endline bytes
 ```
+This will `close_in ic` at the end of the current expression, even if an
+exception is raised.
 
 See the `examples/` directory for more examples.
+
+## Trying it out from source
+
+`make repl` will start a custom utop session with the current source tree's
+version of the ppx extension loaded and ready to use.

examples/jbuild

@@ -3,3 +3,7 @@
 (executable
  ((name ic)
   (preprocess (pps (ppx_defer)))))
+
+(alias
+ ((name example)
+  (deps (ic.exe))))

src/jbuild

@@ -6,8 +6,6 @@
   (synopsis "Defer evaluation of expressions")
   (modules (ppx_defer))
   (libraries (compiler-libs.common
-              ocaml-migrate-parsetree
-              ppx_tools_versioned
-              ppx_tools_versioned.metaquot_404))
+              ocaml-migrate-parsetree))
   (kind ppx_rewriter)
-  (preprocess (pps (ppx_tools_versioned.metaquot_404)))))
+  (preprocess (pps (ppx_tools_versioned.metaquot_406)))))

src/ppx_defer.ml

@@ -1,5 +1,5 @@
 open Migrate_parsetree
-open OCaml_404.Ast
+open OCaml_406.Ast
 open Ast_mapper
 open Parsetree
 
@@ -68,5 +68,5 @@ let defer_mapper =
   }
 
 let () =
-  Driver.register ~name:"ppx_defer" Versions.ocaml_404
+  Driver.register ~name:"ppx_defer" Versions.ocaml_406
     (fun _config _cookies -> defer_mapper)