package re

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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@gmail.com

Sources

re-1.12.0.tbz
sha256=a01f2bf22f72c2f4ababd8d3e7635e35c1bf6bc5a41ad6d5a007454ddabad1d4
sha512=f0726826e1e677f7ecdf447d46d814a11d3844ec6e5c0527be8c73c7afdb08aacfca47ea764eda325bcd7064aff07c1d3441c935ee5a0fc99ede8707f81a451d

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 (3)

  1. seq
  2. dune >= "2.0"
  3. ocaml >= "4.12"

Dev Dependencies (1)

  1. ounit2 with-test

Optional Dependencies

None

  1. alcotest
  2. alcotest-async
  3. alcotest-lwt
  4. alcotest-mirage
  5. alice
  6. ansifmt >= "1.0.0~pre2"
  7. atd >= "2.2.1"
  8. atd-jsonlike
  9. atdcpp
  10. atdd
  11. atdgen >= "2.3.3"
  12. atdgen-runtime = "2.2.1"
  13. atdj >= "2.2.1"
  14. atdpy >= "2.4.1"
  15. atds < "2.3.3"
  16. atdts
  17. aws-config
  18. awsm-codegen
  19. awso
  20. BetterErrors
  21. bancos
  22. bap-byteweight-frontend
  23. bap-callgraph-collator
  24. bap-fsi-benchmark
  25. bap-ida
  26. bap-objdump
  27. bap-print
  28. bap-radare2
  29. bibfmt
  30. bio_io >= "0.5.1"
  31. biocaml
  32. bonsai >= "v0.15.0"
  33. brot
  34. caisar >= "4.0"
  35. calculon
  36. calculon-web
  37. caldav
  38. calendar >= "3.0.0"
  39. camlp5 >= "8.02.01"
  40. camlp5-buildscripts
  41. camyll
  42. caqti >= "1.7.0"
  43. cascade
  44. catala
  45. catala-format >= "1.2.0"
  46. chamo
  47. ciao_lwt
  48. cinaps
  49. cohttp
  50. coin < "0.1.5"
  51. colibri2
  52. commons
  53. conan >= "0.0.6"
  54. console
  55. core_bench
  56. core_extended
  57. cosovo
  58. cowabloga >= "0.4.0"
  59. crs
  60. cucumber
  61. cuid
  62. current
  63. current_web
  64. daypack-lib
  65. debian-formats
  66. decompress < "1.0.0"
  67. dns < "4.4.1"
  68. docfd >= "13.0.0"
  69. doi2bib
  70. dose3
  71. dune-glob >= "3.21.0"
  72. dune-release >= "0.2.0"
  73. dunolint >= "0.0.20251006"
  74. dunolint-lib
  75. dunolint-lib-base
  76. duppy >= "0.9.5"
  77. eliom >= "13.0.0"
  78. elpi
  79. expect >= "0.1.0"
  80. expect_test_helpers_core
  81. expect_test_helpers_kernel
  82. ez_file
  83. ez_search
  84. fat-filesystem
  85. git-split < "1.0.0"
  86. gpiod
  87. graphql_parser >= "0.11.0"
  88. hardcaml_verify
  89. hardcaml_waveterm
  90. hardcaml_xilinx_components
  91. hegel >= "0.24.1"
  92. hlarp >= "0.0.3"
  93. humane-re
  94. icalendar
  95. index
  96. index-bench
  97. irmin-bench
  98. jingoo >= "1.2.21"
  99. js_of_ocaml >= "3.10.0"
  100. js_of_ocaml-compiler >= "3.10.0"
  101. js_of_ocaml-lwt >= "3.10.0"
  102. js_of_ocaml-ocamlbuild >= "3.10.0" & < "5.0"
  103. js_of_ocaml-ppx >= "3.10.0"
  104. js_of_ocaml-ppx_deriving_json >= "3.10.0"
  105. js_of_ocaml-toplevel >= "3.10.0"
  106. js_of_ocaml-tyxml >= "3.10.0"
  107. jsonschema
  108. jsonschema-core
  109. jsonschema-validation
  110. jwt
  111. jwto
  112. k7
  113. kappa-library
  114. kubecaml
  115. lastfm >= "0.3.4"
  116. ldap >= "2.5.1"
  117. learn-ocaml
  118. ledes
  119. lipsum
  120. liquidsoap >= "2.3.3"
  121. liquidsoap-core >= "2.3.0"
  122. liquidsoap-lang >= "2.3.0"
  123. lwt_ppx_to_let_syntax
  124. MlFront_Cli >= "2.1.4~prerel2" & < "2.3.1"
  125. MlFront_Core >= "2.4.2.30"
  126. MlFront_ZipFile
  127. magic-trace
  128. mdx
  129. mehari < "0.5"
  130. mnet-cli >= "0.0.3" & < "0.0.8"
  131. mparser-re
  132. naboris
  133. netsnmp
  134. ninja_utils
  135. nx-text
  136. obelisk >= "0.5.0"
  137. ocaml-lsp-server >= "1.9.0"
  138. ocamlformat
  139. ocamlformat-mlx
  140. ocamlformat-rpc < "0.21.0"
  141. ocamlmig
  142. ocgtk < "0.1~preview2"
  143. ocp-build
  144. ocp-index
  145. ocsigen-start
  146. ocsigenserver >= "5.1.0"
  147. opam-bin >= "0.9.5" & < "1.1.0"
  148. opam-client < "2.6.0~alpha1"
  149. opam-compiler
  150. opam-core
  151. opam-format >= "2.0.8" & != "2.1.0~beta4" & < "2.6.0~alpha1"
  152. opam-lib
  153. opam-solver >= "2.0.8" & < "2.1.0" | >= "2.2.0" & < "2.6.0~alpha1"
  154. opam-state >= "2.2.0" & < "2.6.0~alpha1"
  155. opam_bin_lib
  156. opium
  157. opium_kernel
  158. oranger
  159. orun
  160. ostap
  161. oxbow
  162. ozulip
  163. pa_ppx_parsetree
  164. pa_ppx_regexp >= "0.04"
  165. pa_ppx_string
  166. parseff
  167. patdiff
  168. pgocaml >= "2.3"
  169. pgx
  170. plato
  171. playwright
  172. podge >= "0.3"
  173. ppx_css < "v0.17.0"
  174. ppx_cstubs
  175. ppx_elpi
  176. ppx_expect < "v0.17.0"
  177. ppx_expect_nobase = "v0.17.2.2"
  178. ppx_mikmatch
  179. ppx_minidebug >= "1.6.0"
  180. ppx_regexp >= "0.3.2"
  181. ppx_test
  182. ppx_tyre
  183. ppxlib >= "0.21.1"
  184. prometheus >= "0.2"
  185. prometheus-app < "2.0"
  186. prometheus-reporter
  187. pyml_bindgen >= "0.3.1"
  188. raga
  189. rdf
  190. re_parser
  191. redis
  192. regrade
  193. rfc1951 < "1.0.0"
  194. safemoney >= "0.3.0"
  195. saga
  196. sarek
  197. sarif >= "0.2.1"
  198. satyrographos
  199. semantic_version
  200. sexp_pretty
  201. shakuhachi
  202. simple-diff
  203. slug
  204. smtml >= "0.21.0"
  205. snf_mcp
  206. sosie
  207. soupault
  208. spectrum >= "0.7.0"
  209. spectrum_capabilities
  210. spectrum_palette_ppx
  211. spectrum_tools
  212. spoc
  213. statocaml_profile
  214. stem
  215. swagger
  216. talon < "1.0.0~alpha3"
  217. testcontainers
  218. testo
  219. testo-lwt
  220. testo-util
  221. tezt
  222. timere-parse
  223. touist >= "3.5.0"
  224. tw < "1.1.0"
  225. tyre >= "0.4"
  226. tyxml >= "4.2.0"
  227. tyxml-ppx >= "5.0.0"
  228. tyxml-syntax
  229. unic
  230. uri < "4.0.0"
  231. uri-re
  232. user-agent-parser
  233. user-setup
  234. uuuu < "0.4.0"
  235. validate
  236. vendredi
  237. wasm_of_ocaml-compiler
  238. wax-lib
  239. webmachine
  240. wire
  241. 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 8a77e58. 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.

This version is not in the latest run; the versions below are.

Version OCaml 4.11 OCaml 4.14 OCaml 5.2 OCaml 5.4 OCaml 5.5
1.14.0 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