diff options
Diffstat (limited to 'lib/impure/re.nim')
| -rw-r--r-- | lib/impure/re.nim | 121 |
1 files changed, 97 insertions, 24 deletions
diff --git a/lib/impure/re.nim b/lib/impure/re.nim index 0c96876b9..053c6ab55 100644 --- a/lib/impure/re.nim +++ b/lib/impure/re.nim @@ -17,6 +17,10 @@ when defined(js): ## C library. This means that your application will depend on the PCRE ## library's licence when using this module, which should not be a problem ## though. +## +## .. note:: There are also alternative nimble packages such as [tinyre](https://github.com/khchen/tinyre) +## and [regex](https://github.com/nitely/nim-regex). +## ## PCRE's licence follows: ## ## .. include:: ../../doc/regexprs.txt @@ -32,7 +36,10 @@ runnableExamples: # can't match start of string since we're starting at 1 import - pcre, strutils, rtarrays + std/[pcre, strutils, rtarrays] + +when defined(nimPreviewSlimSystem): + import std/syncio const MaxSubpatterns* = 20 @@ -41,12 +48,12 @@ const type RegexFlag* = enum ## options for regular expressions - reIgnoreCase = 0, ## do caseless matching - reMultiLine = 1, ## `^` and `$` match newlines within data - reDotAll = 2, ## `.` matches anything including NL - reExtended = 3, ## ignore whitespace and `#` comments - reStudy = 4 ## study the expression (may be omitted if the - ## expression will be used only once) + reIgnoreCase = 0, ## do caseless matching + reMultiLine = 1, ## `^` and `$` match newlines within data + reDotAll = 2, ## `.` matches anything including NL + reExtended = 3, ## ignore whitespace and `#` comments + reStudy = 4 ## study the expression (may be omitted if the + ## expression will be used only once) RegexDesc = object h: ptr Pcre @@ -58,10 +65,16 @@ type ## is raised if the pattern is no valid regular expression. when defined(gcDestructors): - proc `=destroy`(x: var RegexDesc) = - pcre.free_substring(cast[cstring](x.h)) - if not isNil(x.e): - pcre.free_study(x.e) + when defined(nimAllowNonVarDestructor): + proc `=destroy`(x: RegexDesc) = + pcre.free_substring(cast[cstring](x.h)) + if not isNil(x.e): + pcre.free_study(x.e) + else: + proc `=destroy`(x: var RegexDesc) = + pcre.free_substring(cast[cstring](x.h)) + if not isNil(x.e): + pcre.free_study(x.e) proc raiseInvalidRegex(msg: string) {.noinline, noreturn.} = var e: ref RegexError @@ -141,6 +154,10 @@ proc matchOrFind(buf: cstring, pattern: Regex, matches: var openArray[string], else: matches[i-1] = "" return rawMatches[1] - rawMatches[0] +const MaxReBufSize* = high(cint) + ## Maximum PCRE (API 1) buffer start/size equal to `high(cint)`, which even + ## for 64-bit systems can be either 2`31`:sup:-1 or 2`63`:sup:-1. + proc findBounds*(buf: cstring, pattern: Regex, matches: var openArray[string], start = 0, bufSize: int): tuple[first, last: int] = ## returns the starting position and end position of `pattern` in `buf` @@ -148,6 +165,9 @@ proc findBounds*(buf: cstring, pattern: Regex, matches: var openArray[string], ## and the captured ## substrings in the array `matches`. If it does not match, nothing ## is written into `matches` and `(-1,0)` is returned. + ## + ## Note: The memory for `matches` needs to be allocated before this function is + ## called, otherwise it will just remain empty. var rtarray = initRtArray[cint]((matches.len+1)*3) rawMatches = rtarray.getRawData @@ -167,16 +187,27 @@ proc findBounds*(s: string, pattern: Regex, matches: var openArray[string], ## and the captured substrings in the array `matches`. ## If it does not match, nothing ## is written into `matches` and `(-1,0)` is returned. - result = findBounds(cstring(s), pattern, matches, start, s.len) + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. + runnableExamples: + var matches = newSeq[string](1) + let (first, last) = findBounds("Hello World", re"(W\w+)", matches) + doAssert first == 6 + doAssert last == 10 + doAssert matches[0] == "World" + result = findBounds(cstring(s), pattern, matches, + min(start, MaxReBufSize), min(s.len, MaxReBufSize)) proc findBounds*(buf: cstring, pattern: Regex, matches: var openArray[tuple[first, last: int]], - start = 0, bufSize = 0): tuple[first, last: int] = + start = 0, bufSize: int): tuple[first, last: int] = ## returns the starting position and end position of `pattern` in `buf` ## (where `buf` has length `bufSize` and is not necessarily `'\0'` terminated), ## and the captured substrings in the array `matches`. ## If it does not match, nothing is written into `matches` and ## `(-1,0)` is returned. + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. var rtarray = initRtArray[cint]((matches.len+1)*3) rawMatches = rtarray.getRawData @@ -197,7 +228,28 @@ proc findBounds*(s: string, pattern: Regex, ## and the captured substrings in the array `matches`. ## If it does not match, nothing is written into `matches` and ## `(-1,0)` is returned. - result = findBounds(cstring(s), pattern, matches, start, s.len) + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. + runnableExamples: + var matches = newSeq[tuple[first, last: int]](1) + let (first, last) = findBounds("Hello World", re"(\w+)", matches) + doAssert first == 0 + doAssert last == 4 + doAssert matches[0] == (0, 4) + result = findBounds(cstring(s), pattern, matches, + min(start, MaxReBufSize), min(s.len, MaxReBufSize)) + +proc findBoundsImpl(buf: cstring, pattern: Regex, + start = 0, bufSize = 0, flags = 0): tuple[first, last: int] = + var rtarray = initRtArray[cint](3) + let rawMatches = rtarray.getRawData + let res = pcre.exec(pattern.h, pattern.e, buf, bufSize.cint, start.cint, flags.int32, + cast[ptr cint](rawMatches), 3) + + if res < 0'i32: + result = (-1, 0) + else: + result = (int(rawMatches[0]), int(rawMatches[1]-1)) proc findBounds*(buf: cstring, pattern: Regex, start = 0, bufSize: int): tuple[first, last: int] = @@ -220,7 +272,8 @@ proc findBounds*(s: string, pattern: Regex, ## Note: there is a speed improvement if the matches do not need to be captured. runnableExamples: assert findBounds("01234abc89", re"abc") == (5,7) - result = findBounds(cstring(s), pattern, start, s.len) + result = findBounds(cstring(s), pattern, + min(start, MaxReBufSize), min(s.len, MaxReBufSize)) proc matchOrFind(buf: cstring, pattern: Regex, start, bufSize: int, flags: cint): cint = var @@ -236,6 +289,8 @@ proc matchLen*(s: string, pattern: Regex, matches: var openArray[string], ## the same as `match`, but it returns the length of the match, ## if there is no match, `-1` is returned. Note that a match length ## of zero can happen. + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. result = matchOrFind(cstring(s), pattern, matches, start.cint, s.len.cint, pcre.ANCHORED) proc matchLen*(buf: cstring, pattern: Regex, matches: var openArray[string], @@ -243,6 +298,8 @@ proc matchLen*(buf: cstring, pattern: Regex, matches: var openArray[string], ## the same as `match`, but it returns the length of the match, ## if there is no match, `-1` is returned. Note that a match length ## of zero can happen. + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. return matchOrFind(buf, pattern, matches, start.cint, bufSize.cint, pcre.ANCHORED) proc matchLen*(s: string, pattern: Regex, start = 0): int {.inline.} = @@ -273,6 +330,7 @@ proc match*(s: string, pattern: Regex, matches: var openArray[string], ## match, nothing is written into `matches` and `false` is ## returned. ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. runnableExamples: import std/sequtils var matches: array[2, string] @@ -287,14 +345,18 @@ proc match*(buf: cstring, pattern: Regex, matches: var openArray[string], ## match, nothing is written into `matches` and `false` is ## returned. ## `buf` has length `bufSize` (not necessarily `'\0'` terminated). + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. result = matchLen(buf, pattern, matches, start, bufSize) != -1 proc find*(buf: cstring, pattern: Regex, matches: var openArray[string], - start = 0, bufSize = 0): int = + start = 0, bufSize: int): int = ## returns the starting position of `pattern` in `buf` and the captured ## substrings in the array `matches`. If it does not match, nothing ## is written into `matches` and `-1` is returned. ## `buf` has length `bufSize` (not necessarily `'\0'` terminated). + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. var rtarray = initRtArray[cint]((matches.len+1)*3) rawMatches = rtarray.getRawData @@ -313,6 +375,8 @@ proc find*(s: string, pattern: Regex, matches: var openArray[string], ## returns the starting position of `pattern` in `s` and the captured ## substrings in the array `matches`. If it does not match, nothing ## is written into `matches` and `-1` is returned. + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. result = find(cstring(s), pattern, matches, start, s.len) proc find*(buf: cstring, pattern: Regex, start = 0, bufSize: int): int = @@ -382,7 +446,7 @@ iterator findAll*(buf: cstring, pattern: Regex, start = 0, bufSize: int): string proc findAll*(s: string, pattern: Regex, start = 0): seq[string] {.inline.} = ## returns all matching `substrings` of `s` that match `pattern`. - ## If it does not match, @[] is returned. + ## If it does not match, `@[]` is returned. result = @[] for x in findAll(s, pattern, start): result.add x @@ -396,7 +460,7 @@ template `=~` *(s: string, pattern: Regex): untyped = elif line =~ re"\s*(\#.*)": # matches a comment # note that the implicit `matches` array is different from 1st branch result = $(matches[0],) - else: doAssert false + else: raiseAssert "unreachable" doAssert not declared(matches) doAssert parse("NAME = LENA") == """("NAME", "LENA")""" doAssert parse(" # comment ... ") == """("# comment ... ",)""" @@ -414,6 +478,8 @@ proc contains*(s: string, pattern: Regex, start = 0): bool {.inline.} = proc contains*(s: string, pattern: Regex, matches: var openArray[string], start = 0): bool {.inline.} = ## same as `find(s, pattern, matches, start) >= 0` + ## + ## .. note:: The memory for `matches` needs to be allocated before this function is called, otherwise it will just remain empty. return find(s, pattern, matches, start) >= 0 proc startsWith*(s: string, prefix: Regex): bool {.inline.} = @@ -433,12 +499,16 @@ proc replace*(s: string, sub: Regex, by = ""): string = doAssert "var1=key; var2=key2".replace(re"(\w+)=(\w+)", "?") == "?; ?" result = "" var prev = 0 + var flags = int32(0) while prev < s.len: - var match = findBounds(s, sub, prev) + var match = findBoundsImpl(s.cstring, sub, prev, s.len, flags) + flags = 0 if match.first < 0: break add(result, substr(s, prev, match.first-1)) add(result, by) - if match.last + 1 == prev: break + if match.first > match.last: + # 0-len match + flags = pcre.NOTEMPTY_ATSTART prev = match.last + 1 add(result, substr(s, prev)) @@ -499,19 +569,22 @@ iterator split*(s: string, sep: Regex; maxsplit = -1): string = @["", "this", "is", "an", "example", ""] var last = 0 var splits = maxsplit - var x: int + var x = -1 + if len(s) == 0: + last = 1 + if matchLen(s, sep, 0) == 0: + x = 0 while last <= len(s): var first = last var sepLen = 1 + if x == 0: + inc(last) while last < len(s): x = matchLen(s, sep, last) if x >= 0: sepLen = x break inc(last) - if x == 0: - if last >= len(s): break - inc last if splits == 0: last = len(s) yield substr(s, first, last-1) if splits == 0: break |