ppx_type_conv

Deprecated: use ppxlib instead
README

What is type_conv?

The type_conv library factors out functionality needed by different
preprocessors that generate code from type specifications. Example
libraries currently depending on type_conv:

  • ppx_bin_prot

  • ppx_compare

  • ppx_fields_conv

  • ppx_sexp_conv

  • ppx_variants_conv

type_conv for users of ppx_deriving

type_conv based code generators are meant to be used with
ppx_driver. However
type_conv allows to export a compatible ppx_deriving plugin.
By default, when not linked as part of a driver, packages using
type_conv will just use ppx_deriving.

So for instance this will work as expected using ppx_deriving:

ocamlfind ocamlc -c -package ppx_sexp_conv foo.ml

For end users, the main advantage of using type_conv based
generators with ppx_driver is that it will catch typos and attributes
misplacement. For instance:

# type t = int [@@derivin sexp]
Error: Attribute `derivin' was not used
Hint: Did you mean deriving?
# type t = int [@@deriving sxp]
Error: ppx_type_conv: 'sxp' is not a supported type type-conv generator
Hint: Did you mean sexp?
# type t = int [@deriving sexp]
Error: Attribute `deriving' was not used
Hint: `deriving' is available for type declarations, type extensions
and extension constructors but is used here in the context of a core type.
Did you put it at the wrong level?"

For instruction on how to use ppx_driver, refer to the
ppx_driver's documentation.

Syntax

This part is only relevant if you are using ppx_driver. If you are
using ppx_deriving the syntax is the one of ppx_deriving.

type_conv interprets the [@@deriving ...] attributes on type
declarations, exception declarations and extension constructor
declarations:

type t = A | B [@@deriving sexp, bin_io]

sexp and bin_io are called generators. They are functions that
generate code given the declaration. These functions are implemented
by external libraries such as ppx_sexp_conv or
ppx_bin_prot. type_conv itself provides no generator, it does only
the dispatch.

Generators can take arguments. This is done using the following syntax:

type t = A | B [@@deriving foo ~arg:42]

For arguments that are just switches, it is common to use the
following syntax:

type t = A | B [@@deriving foo ~bar]

Plugin as findlib libraries

You must essentially follow the same rule for ppx_type_conv plugins
as for ppx_driver ones when writing the META file.

Contact Information and Contributing

In the case of bugs, feature requests, contributions and similar, please
contact the maintainers:

Up-to-date information should be available at https://github.com/janestreet/ppx_type_conv.

Install
Published
22 Mar 2018
Sources
ppx_type_conv-v0.11.0.tar.gz
md5=34a6339cf7259e114b2946c615fed9b8
Dependencies
ppxlib
>= "0.1.0" & < "0.9.0"
jbuilder
>= "1.0+beta18.1"
ocaml
>= "4.04.1"
Reverse Dependencies
charrua-core
>= "0.3" & < "0.5"
cohttp
>= "1.0.2" & < "1.1.1"
diet
< "0.2"
mirage-block-unix
>= "2.10.0" & < "2.11.1"
ppx_jsobject_conv
< "0.2.1" | >= "0.4.2" & < "0.6.0"
qcow
< "0.11.0"
qcow-format
>= "0.4"