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-1.11.0.tbz
sha256=01fc244780c0f6be72ae796b1fb750f367de18624fd75d07ee79782ed6df8d4f
sha512=3e3712cc1266ec1f27620f3508ea2ebba338f4083b07d8a69dccee1facfdc1971a6c39f9deea664d2a62fd7f2cfd2eae816ca4c274acfadaee992a3befc4b757

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 >= "4.03"

Dev Dependencies (1)

  1. ounit with-test

Optional Dependencies

None

  1. alcobar >= "0.5.0"
  2. alcotest
  3. alcotest-async
  4. alcotest-lwt
  5. alcotest-mirage
  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 = "0.0.5"
  53. console
  54. core_bench
  55. core_extended
  56. cosovo
  57. cowabloga >= "0.4.0"
  58. cucumber
  59. cuid
  60. current
  61. current_web
  62. daypack-lib
  63. debian-formats
  64. decompress < "1.0.0"
  65. dns < "4.4.1"
  66. docfd >= "13.0.0"
  67. doi2bib
  68. dose3
  69. dune-glob >= "3.21.0"
  70. dune-release >= "0.2.0"
  71. dune-rpc >= "3.25.0"
  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_test_helpers_core
  79. expect_test_helpers_kernel
  80. ez_file
  81. ez_search
  82. fat-filesystem
  83. git-split < "1.0.0"
  84. gpiod
  85. graphql_parser >= "0.11.0"
  86. hardcaml_verify
  87. hardcaml_waveterm
  88. hardcaml_xilinx_components
  89. hlarp >= "0.0.3"
  90. humane-re
  91. icalendar
  92. index
  93. index-bench
  94. irmin-bench
  95. jingoo >= "1.2.21"
  96. js_of_ocaml >= "3.10.0"
  97. js_of_ocaml-compiler >= "3.10.0"
  98. js_of_ocaml-lwt >= "3.10.0"
  99. js_of_ocaml-ocamlbuild >= "3.10.0" & < "5.0"
  100. js_of_ocaml-ppx >= "3.10.0"
  101. js_of_ocaml-ppx_deriving_json >= "3.10.0"
  102. js_of_ocaml-toplevel >= "3.10.0"
  103. js_of_ocaml-tyxml >= "3.10.0"
  104. jsonschema
  105. jsonschema-core
  106. jsonschema-validation
  107. jwt
  108. jwto
  109. k7
  110. kappa-agents >= "4.1.3"
  111. kappa-binaries >= "4.1.3"
  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"
  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 < "0.5"
  129. mnet-cli >= "0.0.3" & < "0.0.8"
  130. mparser-re
  131. naboris
  132. netsnmp
  133. ninja_utils
  134. nx-text
  135. obelisk >= "0.5.0"
  136. ocaml-lsp-server >= "1.9.0"
  137. ocamlformat
  138. ocamlformat-mlx
  139. ocamlformat-rpc < "0.21.0"
  140. ocamlmig
  141. ocgtk < "0.1~preview2"
  142. ocp-build
  143. ocp-index
  144. ocsigen-start
  145. ocsigenserver >= "5.1.0"
  146. opam-bin >= "0.9.5" & < "1.1.0"
  147. opam-client < "2.6.0~alpha1"
  148. opam-compiler
  149. opam-core
  150. opam-format >= "2.0.8" & != "2.1.0~beta4" & < "2.6.0~alpha1"
  151. opam-lib
  152. opam-solver >= "2.0.8" & < "2.1.0" | >= "2.2.0" & < "2.6.0~alpha1"
  153. opam-state >= "2.2.0" & < "2.6.0~alpha1"
  154. opam_bin_lib
  155. opium
  156. opium_kernel
  157. oranger
  158. orun
  159. ostap
  160. ozulip
  161. pa_ppx_parsetree
  162. pa_ppx_regexp < "0.04"
  163. pa_ppx_string
  164. parseff
  165. patdiff
  166. pgocaml >= "2.3"
  167. pgx
  168. plato
  169. playwright
  170. podge >= "0.3"
  171. ppx_css < "v0.17.0"
  172. ppx_cstubs
  173. ppx_elpi
  174. ppx_expect < "v0.17.0"
  175. ppx_expect_nobase = "v0.17.2.2"
  176. ppx_mikmatch
  177. ppx_minidebug >= "1.6.0"
  178. ppx_regexp >= "0.3.2"
  179. ppx_test
  180. ppx_tyre
  181. ppxlib >= "0.21.1"
  182. prometheus >= "0.2"
  183. prometheus-app < "2.0"
  184. prometheus-reporter
  185. pyml_bindgen >= "0.3.1"
  186. raga
  187. rdf
  188. re_parser
  189. redis
  190. regrade
  191. rfc1951 < "1.0.0"
  192. safemoney >= "0.3.0"
  193. saga
  194. sarek
  195. sarif >= "0.2.1"
  196. satyrographos
  197. semantic_version
  198. sexp_pretty
  199. shakuhachi
  200. simple-diff
  201. slug
  202. smtml >= "0.21.0"
  203. snf_mcp
  204. sosie
  205. soupault
  206. spectrum >= "0.7.0"
  207. spectrum_capabilities
  208. spectrum_palette_ppx
  209. spectrum_tools
  210. spoc
  211. stem
  212. swagger
  213. talon < "1.0.0~alpha3"
  214. testcontainers
  215. testo
  216. testo-lwt
  217. testo-util
  218. tezt
  219. timere-parse
  220. touist >= "3.5.0"
  221. tw < "1.1.0"
  222. tyre >= "0.4"
  223. tyxml >= "4.2.0"
  224. tyxml-ppx >= "5.0.0"
  225. tyxml-syntax
  226. unic
  227. uri < "4.0.0"
  228. uri-re
  229. user-agent-parser
  230. user-setup
  231. uuuu < "0.4.0"
  232. validate
  233. vendredi
  234. wasm_of_ocaml-compiler
  235. wax-lib
  236. webmachine
  237. wire
  238. 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 78c202b. 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 n/a good good good good
1.11.0 (this version) 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