package re

All checked builds pass
  1. Overview
  2. Docs
RE is a regular expression library for OCaml

Install 

dune-project
 Dependency

github.com Readme Changelog LGPL-2.1-or-later WITH OCaml-LGPL-linking-exception License Edit opam file Versions (20)

Authors

  1. J
    Jerome Vouillon
  2. T
    Thomas Gazagnaire
  3. A
    Anil Madhavapeddy
  4. R
    Rudi Grinberg
  5. Gabriel Radanne

Maintainers

  1. R
    Rudi Grinberg <me@rgrinberg.com>

Sources

1.14.0.tar.gz
md5=03f4a83100cb9229a796b85c698076e1
sha512=cd2cc39f951ca6b7be631bbb5531ed13bc040e629842671bf6fef3911b20ef1653fa9a1f0aa23b094d252cffc9a9efe7ffca69e50d362ab935bc0cc447548124

Description

Pure OCaml regular expressions with:

  • Perl-style regular expressions (module Re.Perl)
  • Posix extended regular expressions (module Re.Posix)
  • Emacs-style regular expressions (module Re.Emacs)
  • Shell-style file globbing (module Re.Glob)
  • Compatibility layer for OCaml's built-in Str module (module Re.Str)

Added to opam-repository:

README

Description

Re is a regular expression library for OCaml. Build status

Contact

This library has been written by Jerome Vouillon (Jerome.Vouillon@pps.univ-paris-diderot.fr). It can be downloaded from https://github.com/ocaml/ocaml-re

Bug reports, suggestions and contributions are welcome.

Features

The following styles of regular expressions are supported:

  • Perl-style regular expressions (module Re.Perl);
  • Posix extended regular expressions (module Re.Posix);
  • Emacs-style regular expressions (module Re.Emacs);
  • Shell-style file globbing (module Re.Glob).

It is also possible to build regular expressions by combining simpler regular expressions (module Re).

The most notable missing features are back-references and look-ahead/look-behind assertions.

There is also a subset of the PCRE interface available in the Re.Pcre module. This makes it easier to port code from that library to Re with minimal changes.

Performances

The matches are performed by lazily building a DFA (deterministic finite automaton) from the regular expression. As a consequence, matching takes linear time in the length of the matched string.

The compilation of patterns is slower than with libraries using back-tracking, such as PCRE. But, once a large enough part of the DFA is built, matching is extremely fast.

Of course, for some combinations of regular expression and string, the part of the DFA that needs to be build is so large that this point is never reached, and matching will be slow. This is not expected to happen often in practice, and actually a lot of expressions that behaves badly with a backtracking implementation are very efficient with this implementation.

The library is at the moment entirely written in OCaml. As a consequence, regular expression matching is much slower when the library is compiled to bytecode than when it is compiled to native code.

Here are some timing results (Pentium III 500Mhz):

  • Scanning a 1Mb string containing only as, except for the last character which is a b, searching for the pattern aa?b (repeated 100 times):

    • RE: 2.6s
    • PCRE: 68s

  • Regular expression example from http://www.bagley.org/~doug/shootout/ [1]

    • RE: 0.43s
    • PCRE: 3.68s

    [1] this page is no longer up but is available via the Internet Archive http://web.archive.org/web/20010429190941/http://www.bagley.org/~doug/shootout/bench/regexmatch/

  • The large regular expression (about 2000 characters long) that Unison uses with my preference file to decide whether a file should be ignored or not. This expression is matched against a filename about 20000 times.

    • RE: 0.31s
    • PCRE: 3.7s However, RE is only faster than PCRE when there are more than about 300 filenames.

Dependencies (2)

  1. ocaml >= "4.13.0"
  2. dune >= "3.17"

Dev Dependencies (5)

  1. odoc with-doc
  2. conf-npm with-test
  3. js_of_ocaml with-test
  4. ounit2 with-test
  5. ppx_expect with-test & >= "v0.17.0"

Optional Dependencies

None

  1. alcotest
  2. alcotest-async
  3. alcotest-lwt
  4. alcotest-mirage
  5. alice
  6. atd >= "2.2.1"
  7. atd-jsonlike
  8. atdcpp
  9. atdd
  10. atdgen >= "2.3.3"
  11. atdgen-runtime = "2.2.1"
  12. atdj >= "2.2.1"
  13. atdpy >= "2.4.1"
  14. atds < "2.3.3"
  15. atdts
  16. aws-config
  17. awsm-codegen
  18. awso
  19. BetterErrors
  20. bancos
  21. bap-byteweight-frontend
  22. bap-callgraph-collator
  23. bap-fsi-benchmark
  24. bap-ida
  25. bap-objdump
  26. bap-print
  27. bap-radare2
  28. bibfmt
  29. bio_io >= "0.5.1"
  30. biocaml
  31. bonsai >= "v0.15.0"
  32. brot
  33. caisar >= "4.0"
  34. calculon
  35. calculon-web
  36. caldav
  37. calendar >= "3.0.0"
  38. camlp5 >= "8.02.01"
  39. camlp5-buildscripts
  40. camyll
  41. caqti >= "1.7.0"
  42. cascade
  43. catala
  44. catala-format >= "1.2.0"
  45. chamo
  46. ciao_lwt
  47. cinaps
  48. cohttp
  49. coin < "0.1.5"
  50. colibri2
  51. commons
  52. conan >= "0.0.6"
  53. console
  54. core_bench
  55. core_extended
  56. cosovo
  57. cowabloga >= "0.4.0"
  58. crs
  59. cucumber
  60. cuid
  61. current
  62. current_web
  63. daypack-lib
  64. debian-formats
  65. decompress < "1.0.0"
  66. dns < "4.4.1"
  67. docfd >= "13.0.0"
  68. doi2bib
  69. dose3
  70. dune-glob >= "3.21.0"
  71. dune-release >= "0.2.0"
  72. dunolint >= "0.0.20251006"
  73. dunolint-lib
  74. dunolint-lib-base
  75. duppy >= "0.9.5"
  76. eliom >= "13.0.0"
  77. elpi
  78. expect >= "0.1.0"
  79. expect_test_helpers_core
  80. expect_test_helpers_kernel
  81. ez_file
  82. ez_search
  83. fat-filesystem
  84. git-split < "1.0.0"
  85. gpiod
  86. graphql_parser >= "0.11.0"
  87. hardcaml_verify
  88. hardcaml_waveterm
  89. hardcaml_xilinx_components
  90. hegel >= "0.24.1"
  91. hlarp >= "0.0.3"
  92. humane-re
  93. icalendar
  94. index
  95. index-bench
  96. irmin-bench
  97. jingoo >= "1.2.21"
  98. js_of_ocaml >= "3.10.0"
  99. js_of_ocaml-compiler >= "3.10.0"
  100. js_of_ocaml-lwt >= "3.10.0"
  101. js_of_ocaml-ocamlbuild >= "3.10.0" & < "5.0"
  102. js_of_ocaml-ppx >= "3.10.0"
  103. js_of_ocaml-ppx_deriving_json >= "3.10.0"
  104. js_of_ocaml-toplevel >= "3.10.0"
  105. js_of_ocaml-tyxml >= "3.10.0"
  106. jsonschema
  107. jsonschema-core
  108. jsonschema-validation
  109. jwt
  110. jwto
  111. k7
  112. kappa-library
  113. kubecaml
  114. lastfm >= "0.3.4"
  115. ldap >= "2.5.1"
  116. learn-ocaml
  117. ledes
  118. lipsum
  119. liquidsoap >= "2.3.3" & < "2.4.2"
  120. liquidsoap-core >= "2.3.0"
  121. liquidsoap-lang >= "2.3.0"
  122. lwt_ppx_to_let_syntax
  123. MlFront_Cli >= "2.1.4~prerel2" & < "2.3.1"
  124. MlFront_Core >= "2.4.2.30"
  125. MlFront_ZipFile
  126. magic-trace
  127. mdx
  128. mehari
  129. menhir-lsp >= "0.1.2"
  130. menhirformat
  131. mnet-cli >= "0.0.3" & < "0.0.8"
  132. mparser-re
  133. naboris
  134. netsnmp
  135. ninja_utils
  136. nx-text
  137. obelisk >= "0.5.0"
  138. ocaml-lsp-server >= "1.9.0"
  139. ocamlformat
  140. ocamlformat-mlx
  141. ocamlformat-rpc < "0.21.0"
  142. ocamlmig
  143. ocgtk < "0.1~preview2"
  144. ocp-build
  145. ocp-index
  146. ocsigen-start
  147. ocsigenserver >= "5.1.0"
  148. opam-bin >= "0.9.5" & < "1.1.0"
  149. opam-client < "2.6.0~alpha1"
  150. opam-compiler
  151. opam-core
  152. opam-format >= "2.0.8" & != "2.1.0~beta4" & < "2.6.0~alpha1"
  153. opam-lib
  154. opam-solver >= "2.0.8" & < "2.1.0" | >= "2.2.0" & < "2.6.0~alpha1"
  155. opam-state >= "2.2.0" & < "2.6.0~alpha1"
  156. opam_bin_lib
  157. opium
  158. opium_kernel
  159. oranger
  160. orun
  161. ostap
  162. oxbow
  163. ozulip
  164. pa_ppx_parsetree
  165. pa_ppx_regexp >= "0.04"
  166. pa_ppx_string
  167. parseff
  168. passage >= "0.3.2"
  169. patdiff
  170. pgocaml >= "2.3"
  171. pgx
  172. plato
  173. playwright
  174. podge >= "0.3"
  175. ppx_css < "v0.17.0"
  176. ppx_cstubs
  177. ppx_elpi
  178. ppx_expect < "v0.17.0"
  179. ppx_expect_nobase = "v0.17.2.2"
  180. ppx_mikmatch
  181. ppx_minidebug >= "1.6.0"
  182. ppx_regexp >= "0.3.2"
  183. ppx_test
  184. ppx_tyre
  185. ppxlib >= "0.21.1"
  186. prometheus >= "0.2"
  187. prometheus-app < "2.0"
  188. prometheus-reporter
  189. pyml_bindgen >= "0.3.1"
  190. raga
  191. rdf
  192. re_parser
  193. redis
  194. regrade
  195. rfc1951 < "1.0.0"
  196. safemoney >= "0.3.0"
  197. saga
  198. sarek
  199. sarif >= "0.2.1"
  200. satyrographos
  201. semantic_version
  202. sexp_pretty
  203. shakuhachi
  204. simple-diff
  205. slug
  206. smtml >= "0.21.0"
  207. snf_mcp
  208. sosie
  209. soupault
  210. spectrum >= "0.7.0"
  211. spectrum_capabilities
  212. spectrum_palette_ppx
  213. spectrum_tools
  214. spoc
  215. statocaml_profile
  216. stem
  217. swagger
  218. talon < "1.0.0~alpha3"
  219. testcontainers
  220. testo
  221. testo-lwt
  222. testo-util
  223. tezt
  224. timere-parse
  225. touist >= "3.5.0"
  226. tw
  227. tyre >= "0.4"
  228. tyxml >= "4.2.0"
  229. tyxml-ppx >= "5.0.0"
  230. tyxml-syntax
  231. unic
  232. uri < "4.0.0"
  233. uri-re
  234. user-agent-parser
  235. user-setup
  236. uuuu < "0.4.0"
  237. validate
  238. vendredi
  239. wasm_of_ocaml-compiler
  240. wax-lib
  241. webmachine
  242. wire
  243. xtmpl >= "0.18.0"

Conflicts

None

Build status

Results of building re with each compiler on check.ci.ocaml.org, run of against opam-repository 7cdc698. All results for this package.

Each result links to its build log. To keep crawlers from overloading the site, build logs require a GitHub sign-in (see ocurrent/opam-health-check). On your first log, GitHub asks you to “Authorize opam-health-check”, the OCurrent app that runs these checks; it sees only your public profile, not your repositories. The sign-in lasts 30 days.

Version OCaml 4.11 OCaml 4.14 OCaml 5.2 OCaml 5.4 OCaml 5.5
1.14.0 (this version) n/a good good good good
1.11.0 good good good good good
  • good Package successfully built
  • partial One of the dependencies failed to build
  • bad Package failed to build
  • n/a Package is not available in this environment
  • internal Internal failure