Merge pull request #2502 from def-/pcre

Fix infinite loop in re.findAll

lib/impure/re.nim

@@ -231,6 +231,7 @@ iterator findAll*(s: string, pattern: Regex, start = 0): string =
     if res < 0'i32: break
     let a = rawMatches[0]
     let b = rawMatches[1]
+    if a == b and a == i: break
     yield substr(s, int(a), int(b)-1)
     i = b
 
@@ -260,9 +261,9 @@ template `=~` *(s: string, pattern: Regex): expr =
   ##   else:
   ##     echo("syntax error")
   ##
-  bind MaxSubPatterns
+  bind MaxSubpatterns
   when not declaredInScope(matches):
-    var matches {.inject.}: array[0..MaxSubpatterns-1, string]
+    var matches {.inject.}: array[MaxSubpatterns, string]
   match(s, pattern, matches)
 
 # ------------------------- more string handling ------------------------------
@@ -320,7 +321,7 @@ proc replacef*(s: string, sub: Regex, by: string): string =
   ##
   ## "var1<-keykey; val2<-key2key2"
   result = ""
-  var caps: array[0..MaxSubpatterns-1, string]
+  var caps: array[MaxSubpatterns, string]
   var prev = 0
   while true:
     var match = findBounds(s, sub, caps, prev)
@@ -338,7 +339,7 @@ proc parallelReplace*(s: string, subs: openArray[
   ## applied in parallel.
   result = ""
   var i = 0
-  var caps: array[0..MaxSubpatterns-1, string]
+  var caps: array[MaxSubpatterns, string]
   while i < s.len:
     block searchSubs:
       for j in 0..high(subs):
@@ -445,7 +446,7 @@ when isMainModule:
 
   assert find("_____abc_______", re"abc") == 5
 
-  var matches: array[0..5, string]
+  var matches: array[6, string]
   if match("abcdefg", re"c(d)ef(g)", matches, 2):
     assert matches[0] == "d"
     assert matches[1] == "g"
@@ -492,7 +493,7 @@ when isMainModule:
   assert("XYZ".match(re"^\d*") == true)
 
   block:
-    var matches: array[0..15, string]
+    var matches: array[16, string]
     if match("abcdefghijklmnop", re"(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)(m)(n)(o)(p)", matches):
       for i in 0..matches.high:
         assert matches[i] == $chr(i + 'a'.ord)

tests/stdlib/treloop.nim

@@ -0,0 +1,9 @@
+discard """
+  output: "@[(, +,  1,  2, )]"
+"""
+
+import re
+
+let str = "(+ 1 2)"
+var tokenRE = re"""[\s,]*(~@|[\[\]{}()'`~^@]|"(?:\\.|[^\\"])*"|;.*|[^\s\[\]{}('"`,;)]*)"""
+echo str.findAll(tokenRE)