package re

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RE is a regular expression library for OCaml

Install 

dune-project
 Dependency

github.com Readme Changelog LGPL-2.0 with OCaml 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-1.10.3.tbz
sha256=846546967f3fe31765935dd40a6460a9424337ecce7b12727fcba49480790ebb
sha512=d02103b7b8b8d8bc797341dcc933554745427f3c1b51b54b4ac9ff81badfd68c94726c57548b08e00ca99f3e09741b54b6500e97c19fc0e8fcefd6dfbe71da7f

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 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 >= "4.02"

Dev Dependencies (1)

  1. ounit with-test

Optional Dependencies

None

  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. calculon
  33. calculon-web
  34. caldav
  35. calendar >= "3.0.0"
  36. camyll
  37. caqti >= "1.7.0"
  38. cascade
  39. catala < "1.0.0~beta"
  40. ciao_lwt
  41. cinaps
  42. cohttp
  43. coin < "0.1.5"
  44. colibri2
  45. conan < "0.0.5"
  46. console
  47. core_bench
  48. core_extended
  49. cosovo
  50. cowabloga >= "0.4.0"
  51. cucumber
  52. cuid
  53. current
  54. current_web
  55. daypack-lib
  56. debian-formats
  57. decompress < "1.0.0"
  58. dns < "4.4.1"
  59. doi2bib
  60. dose3
  61. dune-glob >= "3.21.0"
  62. dune-release >= "0.2.0"
  63. dunolint >= "0.0.20251006"
  64. dunolint-lib
  65. dunolint-lib-base
  66. duppy >= "0.9.5"
  67. elpi
  68. expect_test_helpers_core
  69. expect_test_helpers_kernel
  70. ez_file
  71. ez_search
  72. fat-filesystem
  73. git-split < "1.0.0"
  74. gpiod
  75. graphql_parser >= "0.11.0"
  76. hardcaml_verify
  77. hardcaml_waveterm
  78. hardcaml_xilinx_components
  79. hlarp >= "0.0.3"
  80. humane-re
  81. icalendar
  82. index
  83. index-bench
  84. irmin-bench
  85. jingoo >= "1.2.21"
  86. js_of_ocaml >= "3.10.0"
  87. js_of_ocaml-compiler >= "3.10.0"
  88. js_of_ocaml-lwt >= "3.10.0"
  89. js_of_ocaml-ocamlbuild >= "3.10.0" & < "5.0"
  90. js_of_ocaml-ppx >= "3.10.0"
  91. js_of_ocaml-ppx_deriving_json >= "3.10.0"
  92. js_of_ocaml-toplevel >= "3.10.0"
  93. js_of_ocaml-tyxml >= "3.10.0"
  94. jsonschema
  95. jsonschema-core
  96. jsonschema-validation
  97. jwt
  98. jwto
  99. k7
  100. kappa-library
  101. kubecaml
  102. ldap >= "2.5.1"
  103. learn-ocaml
  104. ledes
  105. lipsum
  106. lwt_ppx_to_let_syntax
  107. magic-trace
  108. mdx
  109. mnet-cli >= "0.0.3" & < "0.0.8"
  110. mparser-re
  111. naboris
  112. netsnmp
  113. ninja_utils
  114. nx-text
  115. obelisk >= "0.5.0"
  116. ocaml-lsp-server >= "1.9.0"
  117. ocamlformat
  118. ocamlformat-mlx
  119. ocamlformat-rpc < "0.21.0"
  120. ocamlmig
  121. ocgtk < "0.1~preview2"
  122. ocp-build
  123. ocp-index
  124. ocsigen-start
  125. opam-bin >= "0.9.5" & < "1.1.0"
  126. opam-client < "2.6.0~alpha1"
  127. opam-compiler
  128. opam-core
  129. opam-format >= "2.0.8" & != "2.1.0~beta4" & < "2.6.0~alpha1"
  130. opam-lib
  131. opam-solver >= "2.0.8" & < "2.1.0" | >= "2.2.0" & < "2.6.0~alpha1"
  132. opam-state >= "2.2.0" & < "2.6.0~alpha1"
  133. opam_bin_lib
  134. opium
  135. opium_kernel
  136. oranger
  137. ostap
  138. ozulip
  139. parseff
  140. patdiff
  141. pgocaml >= "2.3"
  142. pgx
  143. plato
  144. playwright
  145. podge >= "0.3"
  146. ppx_css < "v0.17.0"
  147. ppx_cstubs
  148. ppx_elpi
  149. ppx_expect < "v0.17.0"
  150. ppx_expect_nobase = "v0.17.2.2"
  151. ppx_mikmatch
  152. ppx_minidebug >= "1.6.0"
  153. ppx_regexp >= "0.3.2"
  154. ppx_test
  155. ppx_tyre
  156. ppxlib >= "0.21.1"
  157. prometheus >= "0.2"
  158. prometheus-app < "2.0"
  159. prometheus-reporter
  160. pyml_bindgen >= "0.3.1"
  161. raga
  162. rdf < "1.0.0"
  163. re_parser
  164. redis
  165. rfc1951 < "1.0.0"
  166. safemoney >= "0.3.0"
  167. saga
  168. sarek
  169. sarif >= "0.2.1"
  170. satyrographos
  171. semantic_version
  172. sexp_pretty
  173. shakuhachi
  174. simple-diff
  175. slug
  176. smtml >= "0.21.0"
  177. snf_mcp
  178. sosie
  179. soupault
  180. spoc
  181. stem
  182. swagger
  183. talon < "1.0.0~alpha3"
  184. testo
  185. testo-lwt
  186. testo-util
  187. tezt
  188. timere-parse
  189. touist >= "3.5.0"
  190. tw < "1.1.0"
  191. tyre >= "0.4"
  192. tyxml >= "4.2.0"
  193. tyxml-ppx >= "5.0.0"
  194. tyxml-syntax
  195. unic
  196. uri < "4.0.0"
  197. uri-re
  198. user-agent-parser
  199. user-setup
  200. uuuu < "0.4.0"
  201. validate
  202. vendredi
  203. wasm_of_ocaml-compiler
  204. wax-lib
  205. webmachine
  206. wire < "1.0.0"
  207. 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.

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