package js_of_ocaml-tyxml
Install
Dune Dependency
Authors
Maintainers
Sources
sha256=cdf1dea0d9397a498b630abe8014908b6dd83b10ee0c7ff5777a6443a62983be
sha512=5cf7d883c97f4b81ab73687c8f29b624acaef28c002b5d739108954973671dd5fb4f869d8fedb485b4b17bc8aa10d8b55b30ae7ace21a9350c2a1ac59b28eb60
README.md.html
Js_of_ocaml (jsoo)
Js_of_ocaml is a compiler from OCaml bytecode to JavaScript. It makes it possible to run pure OCaml programs in JavaScript environment like browsers and Node.js.
It is easy to install and use as it works with an existing installation of OCaml, with no need to recompile any library.
It comes with bindings for a large part of the browser APIs.
According to our benchmarks, the generated programs runs typically faster than with the OCaml bytecode interpreter.
We believe this compiler will prove much easier to maintain than a retargeted OCaml compiler, as the bytecode provides a very stable API.
Js_of_ocaml is composed of multiple packages:
js_of_ocaml-compiler, the compiler.
js_of_ocaml-ppx, a ppx syntax extension.
js_of_ocaml, the base library.
js_of_ocaml-ppx_deriving_json
js_of_ocaml-lwt, lwt support.
js_of_ocaml-tyxml, tyxml support.
js_of_ocaml-toplevel, lib and tools to build an ocaml toplevel to javascript.
Requirements
See opam file for version constraints.
optional
Toplevel requirements
tyxml, reactiveData
ocp-indent: needed to support indentation in the toplevel
higlo: needed to support Syntax highlighting in the toplevel
cohttp: needed to build the toplevel webserver
Installation
Opam
opam install js_of_ocaml js_of_ocaml-compiler js_of_ocaml-ppx
Usage
Your program must first be compiled using the OCaml bytecode compiler ocamlc
. JavaScript bindings are provided by the js_of_ocaml
package. The syntax extension is provided by js_of_ocaml-ppx
package.
ocamlfind ocamlc -package js_of_ocaml -package js_of_ocaml-ppx -linkpkg -o cubes.byte cubes.ml
Then, run the js_of_ocaml
compiler to produce JavaScript code:
js_of_ocaml cubes.byte
Features
Most of the OCaml standard library is supported. However,
Most of the Sys module is not supported.
Extra libraries distributed with OCaml (such as Thread) are not supported in general. However,
Bigarray: bigarrays are supported using Typed Arrays
Num: supported
Str: supported
Graphics: partially supported using canvas (see js_of_ocaml-lwt.graphics)
Unix: time related functions are supported
Tail call is not optimized in general. However, mutually recursive functions are optimized:
self recursive functions (when the tail calls are the function itself) are compiled using a loop.
trampolines are used otherwise. More about tail call optimization.
Effect handlers are supported with the --enable=effects
flag.
Data representation
Data representation differs from the usual one. Most notably, integers are 32 bits (rather than 31 bits or 63 bits), which is their natural size in JavaScript, and floats are not boxed. As a consequence, marshalling, polymorphic comparison, and hashing functions can yield results different from usual:
marshalling of floats is not supported (unmarshalling works);
the polymorphic hash function will not give the same results on datastructures containing floats;
these functions may be more prone to stack overflow.
Ocaml | javascript |
---|---|
int | number (32bit int) |
int32 | number (32bit int) |
nativeint | number (32bit int) |
int64 | Object (MlInt64) |
float | number |
string | string or object (MlBytes) |
bytes | object (MlBytes) |
"immediate" (e.g. true, false, None, ()) | number (32bit int) |
"block" | array with tag as first element (e.g. C(1,2) => [tag,1,2] ) |
array | block with tag 0 (e.g. [\|1;2\|] => [0,1,2] ) |
tuple | block with tag 0 (e.g. (1,2) => [0,1,2] ) |
record | block (e.g. {x=1;y=2} => [0,1,2] ) |
constructor with arguments | block (e.g. C (1, 2) => [tag,1,2] ) |
module | block |
exception and extensible variant | block or immediate |
function | function |
Toplevel
OCaml 4.04.2 includes Base, Core_kernel, Async_kernel, Async_js
OCaml 4.04.0+BER see http://okmij.org/ftp/ML/MetaOCaml.html
OCaml 4.05.0 includes Base, Core_kernel, Async_kernel, Async_js
OCaml 4.06.0 includes Base, Core_kernel, Async_kernel, Async_js
Contents of the distribution
Filename | Description |
---|---|
LICENSE | license and copyright notice |
README | this file |
compiler/ | compiler |
examples/ | small examples |
lib/ | library for interfacing with JavaScript APIs |
ppx/ | ppx syntax extensions |
runtime/ | runtime system |
toplevel/ | web-based OCaml toplevel |