distinction between re.replace and re.replacef; speed improvements for re module

This commit is contained in:
Araq 2011-03-06 21:16:05 +01:00
commit 3005955d20
23 changed files with 206 additions and 171 deletions

View file

@ -1,7 +1,7 @@
#
#
# Nimrod's Runtime Library
# (c) Copyright 2010 Andreas Rumpf
# (c) Copyright 2011 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
@ -32,46 +32,57 @@ type
reIgnoreCase = 0, ## do caseless matching
reMultiLine = 1, ## ``^`` and ``$`` match newlines within data
reDotAll = 2, ## ``.`` matches anything including NL
reExtended = 3 ## ignore whitespace and ``#`` comments
reExtended = 3, ## ignore whitespace and ``#`` comments
reStudy = 4 ## study the expression (may be omitted if the
## expression will be used only once)
TRegExDesc {.pure, final.} = object
h: PPcre
e: ptr TExtra
TRegEx* = ref TRegExDesc ## a compiled regular expression
EInvalidRegEx* = object of EInvalidValue
## is raised if the pattern is no valid regular expression.
proc raiseInvalidRegex(msg: string) {.noinline, noreturn.} =
var e: ref EInvalidRegEx
new(e)
e.msg = msg
raise e
proc rawCompile(pattern: string, flags: cint): PPcre =
var
msg: CString
offset: cint
com = pcre.Compile(pattern, flags, addr(msg), addr(offset), nil)
if com == nil:
var e: ref EInvalidRegEx
new(e)
e.msg = $msg & "\n" & pattern & "\n" & repeatChar(offset) & "^\n"
raise e
return com
result = pcre.Compile(pattern, flags, addr(msg), addr(offset), nil)
if result == nil:
raiseInvalidRegEx($msg & "\n" & pattern & "\n" & repeatChar(offset) & "^\n")
proc finalizeRegEx(x: TRegEx) =
# XXX This is a hack, but PCRE does not export its "free" function properly.
# Sigh. The hack relies on PCRE's implementation (see ``pcre_get.c``).
# Fortunately the implementation is unlikely to change.
pcre.free_substring(cast[cstring](x.h))
if not isNil(x.e):
pcre.free_substring(cast[cstring](x.e))
proc re*(s: string, flags = {reExtended}): TRegEx =
proc re*(s: string, flags = {reExtended, reStudy}): TRegEx =
## Constructor of regular expressions. Note that Nimrod's
## extended raw string literals support this syntax ``re"[abc]"`` as
## a short form for ``re(r"[abc]")``.
new(result, finalizeRegEx)
result.h = rawCompile(s, cast[cint](flags))
result.h = rawCompile(s, cast[cint](flags - {reStudy}))
if reStudy in flags:
var msg: cstring
result.e = pcre.study(result.h, 0, msg)
if not isNil(msg): raiseInvalidRegex($msg)
proc matchOrFind(s: string, pattern: TRegEx, matches: var openarray[string],
start, flags: cint): cint =
var
rawMatches: array[0..maxSubpatterns * 3 - 1, cint]
res = pcre.Exec(pattern.h, nil, s, len(s), start, flags,
res = pcre.Exec(pattern.h, pattern.e, s, len(s), start, flags,
cast[ptr cint](addr(rawMatches)), maxSubpatterns * 3)
if res < 0'i32: return res
for i in 1..int(res)-1:
@ -83,13 +94,13 @@ proc matchOrFind(s: string, pattern: TRegEx, matches: var openarray[string],
proc findBounds*(s: string, pattern: TRegEx, matches: var openarray[string],
start = 0): tuple[first, last: int] =
## returns the starting position and end position of ``pattern`` in ``s``
## returns the starting position and end position of `pattern` in `s`
## and the captured
## substrings in the array ``matches``. If it does not match, nothing
## is written into ``matches`` and (-1,0) is returned.
## substrings in the array `matches`. If it does not match, nothing
## is written into `matches` and ``(-1,0)`` is returned.
var
rawMatches: array[0..maxSubpatterns * 3 - 1, cint]
res = pcre.Exec(pattern.h, nil, s, len(s), start, 0'i32,
res = pcre.Exec(pattern.h, pattern.e, s, len(s), start, 0'i32,
cast[ptr cint](addr(rawMatches)), maxSubpatterns * 3)
if res < 0'i32: return (-1, 0)
for i in 1..int(res)-1:
@ -98,10 +109,40 @@ proc findBounds*(s: string, pattern: TRegEx, matches: var openarray[string],
if a >= 0'i32: matches[i-1] = copy(s, int(a), int(b)-1)
else: matches[i-1] = ""
return (rawMatches[0].int, rawMatches[1].int - 1)
proc findBounds*(s: string, pattern: TRegEx,
matches: var openarray[tuple[first, last: int]],
start = 0): tuple[first, last: int] =
## returns the starting position and end position of ``pattern`` in ``s``
## and the captured substrings in the array `matches`.
## If it does not match, nothing is written into `matches` and
## ``(-1,0)`` is returned.
var
rawMatches: array[0..maxSubpatterns * 3 - 1, cint]
res = pcre.Exec(pattern.h, pattern.e, s, len(s), start, 0'i32,
cast[ptr cint](addr(rawMatches)), maxSubpatterns * 3)
if res < 0'i32: return (-1, 0)
for i in 1..int(res)-1:
var a = rawMatches[i * 2]
var b = rawMatches[i * 2 + 1]
if a >= 0'i32: matches[i-1] = (int(a), int(b)-1)
else: matches[i-1] = (-1,0)
return (rawMatches[0].int, rawMatches[1].int - 1)
proc findBounds*(s: string, pattern: TRegEx,
start = 0): tuple[first, last: int] =
## returns the starting position of `pattern` in `s`. If it does not
## match, ``(-1,0)`` is returned.
var
rawMatches: array[0..3 - 1, cint]
res = pcre.Exec(pattern.h, nil, s, len(s), start, 0'i32,
cast[ptr cint](addr(rawMatches)), 3)
if res < 0'i32: return (int(res), 0)
return (int(rawMatches[0]), int(rawMatches[1]-1))
proc matchOrFind(s: string, pattern: TRegEx, start, flags: cint): cint =
var rawMatches: array [0..maxSubpatterns * 3 - 1, cint]
result = pcre.Exec(pattern.h, nil, s, len(s), start, flags,
result = pcre.Exec(pattern.h, pattern.e, s, len(s), start, flags,
cast[ptr cint](addr(rawMatches)), maxSubpatterns * 3)
if result >= 0'i32:
result = rawMatches[1] - rawMatches[0]
@ -139,7 +180,7 @@ proc find*(s: string, pattern: TRegEx, matches: var openarray[string],
## is written into ``matches`` and -1 is returned.
var
rawMatches: array[0..maxSubpatterns * 3 - 1, cint]
res = pcre.Exec(pattern.h, nil, s, len(s), start, 0'i32,
res = pcre.Exec(pattern.h, pattern.e, s, len(s), start, 0'i32,
cast[ptr cint](addr(rawMatches)), maxSubpatterns * 3)
if res < 0'i32: return res
for i in 1..int(res)-1:
@ -219,31 +260,64 @@ proc endsWith*(s: string, suffix: TRegEx): bool =
for i in 0 .. s.len-1:
if matchLen(s, suffix, i) == s.len - i: return true
proc replace*(s: string, sub: TRegEx, by: string): string =
## Replaces `sub` in `s` by the string `by`. Captures can be accessed in `by`
## with the notation ``$i`` and ``$#`` (see strutils.`%`). Examples:
proc replace*(s: string, sub: TRegEx, by = ""): string =
## Replaces `sub` in `s` by the string `by`. Captures cannot be
## accessed in `by`. Examples:
##
## .. code-block:: nimrod
## "var1=key; var2=key2".replace(re"(\w+)'='(\w+)", "$1<-$2$2")
## "var1=key; var2=key2".replace(re"(\w+)'='(\w+)")
##
## Results in:
##
## .. code-block:: nimrod
##
## "var1<-keykey; val2<-key2key2"
## "; "
result = ""
var prev = 0
while true:
var match = findBounds(s, sub, prev)
if match.first < 0: break
add(result, copy(s, prev, match.first-1))
add(result, by)
prev = match.last + 1
add(result, copy(s, prev))
proc replacef*(s: string, sub: TRegEx, by: string): string =
## Replaces `sub` in `s` by the string `by`. Captures can be accessed in `by`
## with the notation ``$i`` and ``$#`` (see strutils.`%`). Examples:
##
## .. code-block:: nimrod
## "var1=key; var2=key2".replace(re"(\w+)'='(\w+)", "$1<-$2$2")
##
## Results in:
##
## .. code-block:: nimrod
##
## "var1<-keykey; val2<-key2key2"
result = ""
var i = 0
var caps: array[0..maxSubpatterns-1, string]
while i < s.len:
var x = matchLen(s, sub, caps, i)
if x <= 0:
add(result, s[i])
inc(i)
else:
addf(result, by, caps)
inc(i, x)
# copy the rest:
add(result, copy(s, i))
var prev = 0
while true:
var match = findBounds(s, sub, caps, prev)
if match.first < 0: break
add(result, copy(s, prev, match.first-1))
addf(result, by, caps)
prev = match.last + 1
add(result, copy(s, prev))
when false:
result = ""
var i = 0
var caps: array[0..maxSubpatterns-1, string]
while i < s.len:
var x = matchLen(s, sub, caps, i)
if x <= 0:
add(result, s[i])
inc(i)
else:
addf(result, by, caps)
inc(i, x)
# copy the rest:
add(result, copy(s, i))
proc parallelReplace*(s: string, subs: openArray[
tuple[pattern: TRegEx, repl: string]]): string =
@ -376,8 +450,10 @@ when isMainModule:
assert false
assert "var1=key; var2=key2".endsWith(re"\w+=\w+")
assert("var1=key; var2=key2".replace(re"(\w+)=(\w+)", "$1<-$2$2") ==
assert("var1=key; var2=key2".replacef(re"(\w+)=(\w+)", "$1<-$2$2") ==
"var1<-keykey; var2<-key2key2")
assert("var1=key; var2=key2".replace(re"(\w+)=(\w+)", "$1<-$2$2") ==
"$1<-$2$2; $1<-$2$2")
for word in split("00232this02939is39an22example111", re"\d+"):
writeln(stdout, word)