package base

  1. Overview
  2. Docs
Full standard library replacement for OCaml

Install

Dune Dependency

github.com Readme Changelog MIT License Edit opam file Versions (26)

Authors

  1. J
    Jane Street Group, LLC

Maintainers

  1. J
    Jane Street developers

Sources

v0.15.1.tar.gz
sha256=755e303171ea267e3ba5af7aa8ea27537f3394d97c77d340b10f806d6ef61a14

Description

Full standard library replacement for OCaml

Base is a complete and portable alternative to the OCaml standard library. It provides all standard functionalities one would expect from a language standard library. It uses consistent conventions across all of its module.

Base aims to be usable in any context. As a result system dependent features such as I/O are not offered by Base. They are instead provided by companion libraries such as stdio:

https://github.com/janestreet/stdio

Published: 30 Sep 2022

README

README.org

* Base

[[https://github.com/janestreet/base/actions][https://github.com/janestreet/base/actions/workflows/workflow.yml/badge.svg]]

Base is a standard library for OCaml. It provides a standard set of
general purpose modules that are well-tested, performant, and
fully-portable across any environment that can run OCaml code. Unlike
other standard library projects, Base is meant to be used as a
wholesale replacement of the standard library distributed with the
OCaml compiler. In particular it makes different choices and doesn't
re-export features that are not fully portable such as I/O, which are
left to other libraries.

You also might want to browse the [[https://ocaml.janestreet.com/ocaml-core/latest/doc/base/index.html][API Documentation]].

** Installation

Install Base via [[https://opam.ocaml.org][OPAM]]:

#+begin_src
$ opam install base
#+end_src

Base has no runtime dependencies and is fast to build. Its sole build
dependencies are [[https://github.com/ocaml/dune][dune]], which itself requires nothing more than the
compiler, and [[https://github.com/janestreet/sexplib0][sexplib0]].

** Using the OCaml standard library with Base

Base is intended as a full stdlib replacement.  As a result, after an
=open Base=, all the modules, values, types, ... coming from the OCaml
standard library that one normally gets in the default environment are
deprecated.

In order to access these values, one must use the =Caml= library,
which re-exports them all through the toplevel name =Caml=:
=Caml.String=, =Caml.print_string=, ...

** Differences between Base and the OCaml standard library

Programmers who are used to the OCaml standard library should read
through this section to understand major differences between the two
libraries that one should be aware of when switching to Base.

*** Comparison operators

The comparison operators exposed by the OCaml standard library are
polymorphic:

#+begin_src ocaml
val compare : 'a -> 'a -> int
val ( <= ) : 'a -> 'a -> bool
...
#+end_src

What they implement is structural comparison of the runtime
representation of values. Since these are often error-prone,
i.e. they don't correspond to what the user expects, they are not
exposed directly by Base.

To use polymorphic comparison with Base, one should use the =Poly=
module. The default comparison operators exposed by Base are the
integer ones, just like the default arithmetic operators are the
integer ones.

The recommended way to compare arbitrary complex data structures is to
use the specific =compare= functions. For instance:

#+begin_src ocaml
List.compare String.compare x y
#+end_src

The [[https://github.com/janestreet/ppx_compare][ppx_compare]] rewriter
offers an alternative way to write this:

#+begin_src ocaml
[%compare: string list] x y
#+end_src

** Base and ppx code generators

Base uses a few ppx code generators to implement:

- reliable and customizable comparison of OCaml values
- reliable and customizable hash of OCaml values
- conversions between OCaml values and s-expression

However, it doesn't need these code generators to build. What it does
instead is use ppx as a code verification tool during development. It
works in a very similar fashion to
[[https://github.com/janestreet/ppx_expect][expectation tests]].

Whenever you see this in the code source:

#+begin_src ocaml
type t = ... [@@deriving_inline sexp_of]
let sexp_of_t = ...
[@@@end]
#+end_src

the code between the =[@@deriving_inline]= and the =[@@@end]= is
generated code. The generated code is currently quite big and hard to
read, however we are working on making it look like human-written
code.

You can put the following elisp code in your =~/.emacs= file to hide
these blocks:

#+begin_src scheme
(defun deriving-inline-forward-sexp (&optional arg)
  (search-forward-regexp "\\[@@@end\\]") nil nil arg)

(defun setup-hide-deriving-inline ()
  (inline)
  (hs-minor-mode t)
  (let ((hs-hide-comments-when-hiding-all nil))
    (hs-hide-all)))

(require 'hideshow)
(add-to-list 'hs-special-modes-alist
             '(tuareg-mode "\\[@@deriving_inline[^]]*\\]" "\\[@@@end\\]" nil
                           deriving-inline-forward-sexp nil))
(add-hook 'tuareg-mode-hook 'setup-hide-deriving-inline)
#+end_src

Things are not yet setup in the git repository to make it convenient
to change types and update the generated code, but they will be setup
soon.

** OCaml Version Support

Base will maintain compatibility with the latest OCaml release, and the three
prior minor version releases. Because of this, there will be a lag of four
minor versions before features introduced in the Stdlib will reach Base.

** Base coding rules

There are a few coding rules across the code base that are enforced by
lint tools.

These rules are:

- Opening the =Caml= module is not allowed. Inside Base, the OCaml
  stdlib is shadowed and accessible through the =Caml= module. We
  forbid opening =Caml= so that we know exactly where things come
  from.
- =Caml.Foo= modules cannot be aliased, one must use =Caml.Foo=
  explicitly. This is to avoid having to remember a list of aliases
  at the beginning of each file.
- For some modules that are both in the OCaml stdlib and Base, such as
  =String=, we define a module =String0= for common functions that
  cannot be defined directly in =Base.String= to avoid creating a
  circular dependency.  Except for =String= itself, other modules
  are not allowed to use =Caml.String= and must use either =String= or
  =String0= instead.
- Indentation is exactly the one of =ocp-indent=.
- A few other coding style rules enforced by
  [[https://github.com/janestreet/ppx_js_style][ppx_js_style]].

The Base specific coding rules are checked by =ppx_base_lint=, in the
=lint= subfolder. The indentation rules are checked by a wrapper around
=ocp-indent= and the coding style rules are checked by =ppx_js_style=.

These checks are currently not run by =dune=, but it will soon get a
=-dev= flag to run them automatically.

** Sexp (de-)serializers

Most types in Base have ~sexp_of_t~ and ~t_of_sexp~ functions for converting
between values of that type and their sexp representations.

One pair of functions deserves special attention: ~String.sexp_of_t~ and
~String.t_of_sexp~.  These functions have the same types as ~Sexp.of_string~ and
~Sexp.to_string~ but very different behavior.

~String.sexp_of_t~ and ~String.t_of_sexp~ are used to encode and decode strings
"embedded" in a sexp representation. On the other hand, ~Sexp.of_string~ and
~Sexp.to_string~ are used to encode and decode the textual form of
s-expressions.

The following example demonstrates the two pairs of functions in action:

#+begin_src ocaml
  open! Base
  open! Stdio

  (* Embed a string in a sexp *)

  let example_sexp : Sexp.t = List.sexp_of_t String.sexp_of_t [ "hello"; "world" ]

  let () =
    assert (Sexp.equal example_sexp (Sexp.List [ Sexp.Atom "hello"; Sexp.Atom "world" ]))
  ;;

  let () =
    assert (
      List.equal
        String.equal
        [ "hello"; "world" ]
        (List.t_of_sexp String.t_of_sexp example_sexp))
  ;;

  (* Embed a sexp in text (string) *)

  let write_sexp_to_file sexp =
    Out_channel.write_all "/tmp/file" ~data:(Sexp.to_string example_sexp)
  ;;

  (* /tmp/file now contains:

     {v
       (hello world)
     v} *)

  let () =
    assert (Sexp.equal example_sexp (Sexp.of_string (In_channel.read_all "/tmp/file")))
  ;;
#+end_src

Dependencies (4)

  1. dune-configurator
  2. dune >= "2.0.0"
  3. sexplib0 >= "v0.15" & < "v0.16"
  4. ocaml >= "4.10.0"

Dev Dependencies

None

  1. abstract_algebra < "v0.16.0"
  2. accessor = "v0.15.0"
  3. accessor_base = "v0.15.0"
  4. ahrocksdb < "0.2.1"
  5. alcotest-async >= "1.3.0"
  6. arrayjit
  7. async_ssl = "v0.15.0"
  8. azblob
  9. bap-main
  10. bap-recipe
  11. bap-recipe-command
  12. bap-relation
  13. base_bigstring = "v0.15.0"
  14. base_quickcheck = "v0.15.0"
  15. bin_prot = "v0.15.0"
  16. bio_io >= "0.2.1" & < "0.7.0"
  17. bitvec-order
  18. caisar
  19. caisar-ir
  20. caisar-nnet
  21. caisar-onnx
  22. caisar-ovo
  23. caisar-xgboost
  24. camelsnakekebab
  25. camlimages >= "5.0.3"
  26. capnp >= "3.3.0"
  27. cohttp-async >= "2.5.2" & < "2.5.3" | >= "2.5.6" & < "3.0.0" | >= "5.0.0" & != "5.3.0" & < "6.0.0~alpha2"
  28. colibri2
  29. combinat < "3.0"
  30. cookie >= "0.1.8"
  31. core >= "v0.15.0" & < "v0.16.0"
  32. core_kernel = "v0.15.0"
  33. crlibm < "0.3"
  34. cucumber
  35. dotenv
  36. expect_test_helpers_core = "v0.15.0"
  37. FPauth
  38. FPauth-core
  39. FPauth-responses
  40. FPauth-strategies
  41. farith
  42. feather >= "0.2.0"
  43. feather_async
  44. fftw3 >= "0.8" & < "0.8.2"
  45. fieldslib = "v0.15.0"
  46. flow_parser >= "0.159.0"
  47. fontforge-of-ocaml
  48. freetds = "0.6"
  49. GT >= "0.4.0" & < "0.5.2"
  50. gammu >= "0.9.4"
  51. genspio >= "0.0.3"
  52. gobject-introspection
  53. gsl >= "1.22.0" & < "1.24.3"
  54. h1_parser
  55. hacl
  56. hardcaml = "v0.15.0"
  57. hardcaml_circuits < "v0.16.0"
  58. hardcaml_fixed_point < "v0.16.0"
  59. hardcaml_of_verilog < "v0.16.0"
  60. hardcaml_step_testbench < "v0.16.0"
  61. hardcaml_verify < "v0.16.0"
  62. hardcaml_waveterm = "v0.15.0"
  63. hardcaml_xilinx < "v0.16.0"
  64. hardcaml_xilinx_components < "v0.16.0"
  65. higher_kinded = "v0.15.0"
  66. idd
  67. idds
  68. influxdb
  69. influxdb-async
  70. influxdb-lwt
  71. inquire < "0.2.0"
  72. int_repr < "v0.16.0"
  73. jsonaf < "v0.16.0"
  74. jst-config >= "v0.15.0" & < "v0.16.0"
  75. krb < "v0.16.0"
  76. lacaml >= "10.0.1" & < "11.0.7"
  77. lbfgs = "0.9"
  78. learn-ocaml >= "0.12"
  79. learn-ocaml-client
  80. libsvm >= "0.9.4"
  81. lilac
  82. liquid_interpreter
  83. liquid_ml
  84. liquid_parser
  85. liquid_std
  86. liquid_syntax
  87. logical
  88. matplotlib
  89. merge-fmt
  90. mesh-triangle >= "0.9.3" & < "0.9.5"
  91. mmdb >= "0.3.0"
  92. monorobot
  93. neural_nets_lib
  94. non_empty_list
  95. nuscr
  96. OCanren-ppx
  97. obeam >= "0.1.0"
  98. ocaml-r >= "0.1.0"
  99. ocamlformat >= "0.14.3" & < "0.20.0" | >= "0.21.0" & < "0.25.1"
  100. ocamlformat-lib
  101. ocamlformat-rpc < "0.20.0"
  102. opine
  103. owl >= "0.3.7"
  104. pa_ppx = "0.03"
  105. parsexp = "v0.15.0"
  106. parsexp_io = "v0.15.0"
  107. patience_diff = "v0.15.0"
  108. pcre >= "7.3.0" & < "7.4.6"
  109. posixat = "v0.15.0"
  110. postgresql >= "4.1.0" & < "4.6.2"
  111. ppx-owl-opt
  112. ppx_accessor = "v0.15.0"
  113. ppx_assert = "v0.15.0"
  114. ppx_bin_prot = "v0.15.0"
  115. ppx_cold = "v0.15.0"
  116. ppx_compare = "v0.15.0"
  117. ppx_conv_func = "v0.15.0"
  118. ppx_csv_conv = "v0.15.0"
  119. ppx_custom_printf = "v0.15.0"
  120. ppx_deriving_cad
  121. ppx_deriving_hardcaml = "v0.15.0"
  122. ppx_deriving_protocol < "0.8.1"
  123. ppx_deriving_rpc = "7.2.0"
  124. ppx_deriving_scad
  125. ppx_disable_unused_warnings < "v0.16.0"
  126. ppx_enumerate = "v0.15.0"
  127. ppx_expect >= "v0.15.0" & < "v0.16.0"
  128. ppx_fields_conv = "v0.15.0"
  129. ppx_fixed_literal = "v0.15.0"
  130. ppx_hash = "v0.15.0"
  131. ppx_here = "v0.15.0"
  132. ppx_inline_test >= "v0.15.0" & < "v0.16.0"
  133. ppx_js_style = "v0.15.0"
  134. ppx_jsonaf_conv < "v0.16.0"
  135. ppx_let = "v0.15.0"
  136. ppx_log = "v0.15.0"
  137. ppx_module_timer = "v0.15.0"
  138. ppx_open
  139. ppx_optcomp = "v0.15.0"
  140. ppx_optional = "v0.15.0"
  141. ppx_pattern_bind = "v0.15.0"
  142. ppx_protocol_conv >= "5.1.2"
  143. ppx_protocol_conv_json < "3.1.0"
  144. ppx_protocol_conv_msgpack < "3.1.0"
  145. ppx_protocol_conv_xml_light < "3.1.0"
  146. ppx_protocol_conv_yaml < "3.1.0"
  147. ppx_python = "v0.15.0"
  148. ppx_rapper >= "1.0.1"
  149. ppx_sexp_conv >= "v0.15.0" & < "v0.16.0"
  150. ppx_sexp_message = "v0.15.0"
  151. ppx_sexp_value = "v0.15.0"
  152. ppx_stable = "v0.15.0"
  153. ppx_string = "v0.15.0"
  154. ppx_type_directed_value
  155. ppx_typed_fields < "v0.16.0"
  156. ppx_typerep_conv = "v0.15.0"
  157. ppx_variants_conv = "v0.15.0"
  158. ppx_xml_conv = "v0.15.0"
  159. ppx_yojson_conv >= "v0.15.0" & < "v0.16.0"
  160. ppxlib != "0.14.0" & < "0.30.0"
  161. profunctor < "v0.16.0"
  162. protocell
  163. psyche
  164. pyml_bindgen
  165. pyre-ast
  166. pythonlib >= "v0.15.0" & < "v0.16.0"
  167. qinap
  168. range >= "0.6"
  169. record_builder = "v0.15.0"
  170. reparse = "2.1.0"
  171. routes >= "2.0.0"
  172. safemoney >= "0.2.0"
  173. sanddb
  174. secp256k1 >= "0.2.5"
  175. session-cookie
  176. session-cookie-lwt
  177. sexp_grammar < "v0.16.0"
  178. sexp_pretty >= "v0.15.0" & < "v0.16.0"
  179. sexp_select = "v0.15.0"
  180. sihl < "0.1.5"
  181. spin < "0.8.0"
  182. splittable_random = "v0.15.0"
  183. sqlite3 >= "4.2.0" & < "5.0.1"
  184. stdio = "v0.15.0"
  185. string_dict = "v0.15.0"
  186. swipl
  187. tablecloth-native < "0.0.8"
  188. tdigest >= "2.2.0"
  189. tensorboard
  190. tensorflow >= "0.0.11"
  191. time_now = "v0.15.0"
  192. timmy
  193. topological_sort = "v0.15.0"
  194. torch < "v0.16.0"
  195. tqdm
  196. travesty >= "0.6.0" & < "0.8.0"
  197. twostep
  198. typerep = "v0.15.0"
  199. user-agent-parser
  200. variantslib = "v0.15.0"
  201. vcaml = "v0.15.0"
  202. virtual_dom >= "v0.15.0" & < "v0.16.0"
  203. wasmtime
  204. wseg
  205. zanuda
  206. zmq-async
  207. zmq-eio
  208. zmq-lwt < "5.1.0"

Conflicts

None