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

  1. alcotest
  2. alcotest-async
  3. alcotest-lwt
  4. alcotest-mirage
  5. atd >= "2.2.1"
  6. atd-jsonlike
  7. atdcpp
  8. atdd
  9. atdgen >= "2.3.3"
  10. atdgen-runtime = "2.2.1"
  11. atdj >= "2.2.1"
  12. atdpy >= "2.4.1"
  13. atds < "2.3.3"
  14. atdts
  15. aws-config
  16. awsm-codegen
  17. awso
  18. BetterErrors
  19. bancos
  20. bap-byteweight-frontend
  21. bap-callgraph-collator
  22. bap-fsi-benchmark
  23. bap-ida
  24. bap-objdump
  25. bap-print
  26. bap-radare2
  27. bibfmt
  28. bio_io >= "0.5.1"
  29. biocaml
  30. bonsai >= "v0.15.0"
  31. brot
  32. caisar < "4.0"
  33. calculon
  34. calculon-web
  35. caldav
  36. calendar >= "3.0.0"
  37. camlp5 >= "8.02.01"
  38. camlp5-buildscripts
  39. camyll
  40. caqti >= "1.7.0"
  41. cascade
  42. catala
  43. catala-format >= "1.2.0"
  44. chamo
  45. ciao_lwt
  46. cinaps
  47. cohttp
  48. coin < "0.1.5"
  49. colibri2
  50. commons
  51. conan = "0.0.5"
  52. console
  53. core_bench
  54. core_extended
  55. cosovo
  56. cowabloga >= "0.4.0"
  57. cucumber
  58. cuid
  59. current
  60. current_web
  61. daypack-lib
  62. debian-formats
  63. decompress < "1.0.0"
  64. dns < "4.4.1"
  65. docfd >= "13.0.0"
  66. doi2bib
  67. dose3
  68. dune-glob >= "3.21.0"
  69. dune-release >= "0.2.0"
  70. dunolint >= "0.0.20251006"
  71. dunolint-lib
  72. dunolint-lib-base
  73. duppy >= "0.9.5"
  74. eliom >= "13.0.0"
  75. elpi
  76. expect_test_helpers_core
  77. expect_test_helpers_kernel
  78. ez_file
  79. ez_search
  80. fat-filesystem
  81. git-split < "1.0.0"
  82. gpiod
  83. graphql_parser >= "0.11.0"
  84. hardcaml_verify
  85. hardcaml_waveterm
  86. hardcaml_xilinx_components
  87. hlarp >= "0.0.3"
  88. humane-re
  89. icalendar
  90. index
  91. index-bench
  92. irmin-bench
  93. jingoo >= "1.2.21"
  94. js_of_ocaml >= "3.10.0"
  95. js_of_ocaml-compiler >= "3.10.0"
  96. js_of_ocaml-lwt >= "3.10.0"
  97. js_of_ocaml-ocamlbuild >= "3.10.0" & < "5.0"
  98. js_of_ocaml-ppx >= "3.10.0"
  99. js_of_ocaml-ppx_deriving_json >= "3.10.0"
  100. js_of_ocaml-toplevel >= "3.10.0"
  101. js_of_ocaml-tyxml >= "3.10.0"
  102. jsonschema
  103. jsonschema-core
  104. jsonschema-validation
  105. jwt
  106. jwto
  107. k7
  108. kappa-agents >= "4.1.3"
  109. kappa-binaries >= "4.1.3"
  110. kappa-library
  111. kubecaml
  112. lastfm >= "0.3.4"
  113. ldap >= "2.5.1"
  114. learn-ocaml
  115. ledes
  116. lipsum
  117. liquidsoap >= "2.3.3"
  118. liquidsoap-core >= "2.3.0"
  119. liquidsoap-lang >= "2.3.0"
  120. lwt_ppx_to_let_syntax
  121. MlFront_Cli >= "2.1.4~prerel2" & < "2.3.1"
  122. MlFront_Core >= "2.4.2.30"
  123. MlFront_ZipFile
  124. magic-trace
  125. mdx
  126. mehari
  127. mnet-cli >= "0.0.3" & < "0.0.8"
  128. mparser-re
  129. naboris
  130. netsnmp
  131. ninja_utils
  132. nx-text
  133. obelisk >= "0.5.0"
  134. ocaml-lsp-server >= "1.9.0"
  135. ocamlformat
  136. ocamlformat-mlx
  137. ocamlformat-rpc < "0.21.0"
  138. ocamlmig
  139. ocgtk < "0.1~preview2"
  140. ocp-build
  141. ocp-index
  142. ocsigen-start
  143. ocsigenserver >= "5.1.0"
  144. opam-bin >= "0.9.5" & < "1.1.0"
  145. opam-client < "2.6.0~alpha1"
  146. opam-compiler
  147. opam-core
  148. opam-format >= "2.0.8" & != "2.1.0~beta4" & < "2.6.0~alpha1"
  149. opam-lib
  150. opam-solver >= "2.0.8" & < "2.1.0" | >= "2.2.0" & < "2.6.0~alpha1"
  151. opam-state >= "2.2.0" & < "2.6.0~alpha1"
  152. opam_bin_lib
  153. opium
  154. opium_kernel
  155. oranger
  156. orun
  157. ostap
  158. ozulip
  159. pa_ppx_parsetree
  160. pa_ppx_regexp < "0.04"
  161. pa_ppx_string
  162. parseff
  163. patdiff
  164. pgocaml >= "2.3"
  165. pgx
  166. plato
  167. playwright
  168. podge >= "0.3"
  169. ppx_css < "v0.17.0"
  170. ppx_cstubs
  171. ppx_elpi
  172. ppx_expect < "v0.17.0"
  173. ppx_expect_nobase = "v0.17.2.2"
  174. ppx_mikmatch
  175. ppx_minidebug >= "1.6.0"
  176. ppx_regexp >= "0.3.2"
  177. ppx_test
  178. ppx_tyre
  179. ppxlib >= "0.21.1"
  180. prometheus >= "0.2"
  181. prometheus-app < "2.0"
  182. prometheus-reporter
  183. pyml_bindgen >= "0.3.1"
  184. raga
  185. rdf
  186. re_parser
  187. redis
  188. regrade
  189. rfc1951 < "1.0.0"
  190. safemoney >= "0.3.0"
  191. saga
  192. sarek
  193. sarif >= "0.2.1"
  194. satyrographos
  195. semantic_version
  196. sexp_pretty
  197. shakuhachi
  198. simple-diff
  199. slug
  200. smtml >= "0.21.0"
  201. snf_mcp
  202. sosie
  203. soupault
  204. spectrum >= "0.7.0"
  205. spectrum_capabilities
  206. spectrum_palette_ppx
  207. spectrum_tools
  208. spoc
  209. stem
  210. swagger
  211. talon < "1.0.0~alpha3"
  212. testcontainers
  213. testo
  214. testo-lwt
  215. testo-util
  216. tezt
  217. timere-parse
  218. touist >= "3.5.0"
  219. tw < "1.1.0"
  220. tyre >= "0.4"
  221. tyxml >= "4.2.0"
  222. tyxml-ppx >= "5.0.0"
  223. tyxml-syntax
  224. unic
  225. uri < "4.0.0"
  226. uri-re
  227. user-agent-parser
  228. user-setup
  229. uuuu < "0.4.0"
  230. validate
  231. vendredi
  232. wasm_of_ocaml-compiler
  233. wax-lib
  234. webmachine
  235. wire
  236. 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 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