From bc4f6354a9901266acaf63ddb64a438ac2ba2a32 Mon Sep 17 00:00:00 2001
From: Esteban C Borsani <ecastroborsani@gmail.com>
Date: Mon, 18 May 2020 10:50:23 -0300
Subject: [PATCH] Revert " treat start as text[start..^1], fixes #64 (#66)"

This reverts commit 929fb32bf459f31f8deeaa8ffe3e6dbbf2b39667.
---
 src/regex.nim          | 11 +++--------
 src/regex/nfamacro.nim |  6 ++----
 src/regex/nfamatch.nim |  6 ++----
 tests/tests.nim        | 23 ++++++++++++++---------
 4 files changed, 21 insertions(+), 25 deletions(-)

diff --git a/src/regex.nim b/src/regex.nim
index 3af49ce..b5991b1 100644
--- a/src/regex.nim
+++ b/src/regex.nim
@@ -426,11 +426,6 @@ template runeIncAt(s: string, n: var int) =
   else:
     n = s.len+1
 
-template findNextImpl(
-  s, pattern, m, i, isNext: untyped
-): untyped =
-  matchImpl(s, pattern, m, {mfFindMatch}, i, isNext)
-
 iterator findAll*(
   s: string,
   pattern: Regex,
@@ -452,7 +447,7 @@ iterator findAll*(
   var i = start
   var m: RegexMatch
   while i <= len(s):
-    if not findNextImpl(s, pattern, m, i, i > start):
+    if not find(s, pattern, m, i):
       break
     elif m.boundaries.b >= m.boundaries.a:
       doAssert i < m.boundaries.b+1
@@ -502,7 +497,7 @@ iterator split*(s: string, sep: Regex): string {.inline, raises: [].} =
     m: RegexMatch
   # This is pretty much findAll
   while i <= len(s):
-    if not findNextImpl(s, sep, m, i, true):
+    if not find(s, sep, m, i):
       i = s.len+1
       last = s.len+1
     elif m.boundaries.b >= m.boundaries.a:
@@ -544,7 +539,7 @@ func splitIncl*(s: string, sep: Regex): seq[string] {.inline, raises: [].} =
     skipFirst = true
     m: RegexMatch
   while i <= len(s):
-    if not findNextImpl(s, sep, m, i, true):
+    if not find(s, sep, m, i):
       i = s.len+1
       last = s.len+1
     elif m.boundaries.b >= m.boundaries.a:
diff --git a/src/regex/nfamacro.nim b/src/regex/nfamacro.nim
index ed7d690..dc25990 100644
--- a/src/regex/nfamacro.nim
+++ b/src/regex/nfamacro.nim
@@ -448,8 +448,7 @@ func matchImpl*(
   regex: static Regex,
   m: var RegexMatch,
   flags: static MatchFlags,
-  start = 0,
-  isContinuation = false
+  start = 0
 ): bool {.inline.} =
   const eoeNode {.used.} = regex.eoeNode()
   # workaround Nim/issues/13252
@@ -469,8 +468,7 @@ func matchImpl*(
   smB = newSubmatches(regex.nfa.len)
   smA.add((0'i16, -1'i32, start .. start-1))
   when mfFindMatch in flags:
-    if isContinuation and
-        0 <= start-1 and start-1 <= len(text)-1:
+    if 0 <= start-1 and start-1 <= len(text)-1:
       cPrev = bwRuneAt(text, start-1).int32
   while i < len(text):
     fastRuneAt(text, i, c, true)
diff --git a/src/regex/nfamatch.nim b/src/regex/nfamatch.nim
index 808e1c3..23c5537 100644
--- a/src/regex/nfamatch.nim
+++ b/src/regex/nfamatch.nim
@@ -100,8 +100,7 @@ func matchImpl*(
   regex: Regex,
   m: var RegexMatch,
   flags: static MatchFlags,
-  start = 0,
-  isContinuation = false
+  start = 0
 ): bool {.inline.} =
   m.clear()
   var
@@ -115,8 +114,7 @@ func matchImpl*(
   smB = newSubmatches(regex.nfa.len)
   smA.add((0'i16, -1'i32, start .. start-1))
   when mfFindMatch in flags:
-    if isContinuation and
-        0 <= start-1 and start-1 <= len(text)-1:
+    if 0 <= start-1 and start-1 <= len(text)-1:
       cPrev = bwRuneAt(text, start-1).int32
   while i < len(text):
     fastRuneAt(text, i, c, true)
diff --git a/tests/tests.nim b/tests/tests.nim
index 0b2b0ba..363f88e 100644
--- a/tests/tests.nim
+++ b/tests/tests.nim
@@ -1681,18 +1681,26 @@ test "tmisc2":
                 bazz//
     //"""
     check replace(input, re"(?m)$", "//") == expected
-  # We treat start as text[start..^1], see issue #64
-  check find("foobarbar", re"^bar", m, start=3)
-  check find("foobarbar", re"^bar", m, start=3) and
-    m.boundaries == 3 .. 5
-  check find("foobar\nbar", re"(?m)^bar", m, start=4) and
+  check(not find("foobarbar", re"^bar", m, start=3))
+  check find("foobar\nbar", re"(?m)^bar", m, start=3) and
     m.boundaries == 7 .. 9
+  check find("foo\nbar\nbar", re"(?m)^bar", m, start=3) and
+    m.boundaries == 4 .. 6
+  check find("foo\nbar\nbar", re"(?m)^bar", m, start=4) and
+    m.boundaries == 4 .. 6
   block:
     # The bounds must contain the empty match index
     check find("foo\nbar\nbar", re"(?m)^", m) and
       m.boundaries == 0 .. -1
     check find("foo\nbar\nbar", re"(?m)^", m, start=1) and
-      m.boundaries == 1 .. 0
+      m.boundaries == 4 .. 3
+    check find("foo\nbar\nbar", re"(?m)^", m, start=4) and
+      m.boundaries == 4 .. 3
+    check find("foo\nbar\nbar", re"(?m)^", m, start=5) and
+      m.boundaries == 8 .. 7
+    check find("foo\nbar\nbar", re"(?m)^", m, start=8) and
+      m.boundaries == 8 .. 7
+    check(not find("foo\nbar\nbar", re"(?m)^", m, start=9))
     check find("foo\nbar\nbar", re"(?m)$", m) and
       m.boundaries == 3 .. 2
     check find("foo\nbar\nbar", re"(?m)$", m, start=3) and
@@ -1751,6 +1759,3 @@ test "tmisc2":
   check split("aaa", re"a") == @["", "", "", ""]
   check split("a\na\na", re"(?m)^") == @["a\n", "a\n", "a"]
   check split("\n\n", re"(?m)^") == @["\n", "\n"]
-  # issue #64
-  check match("xabc", re"^abc$", m, start = 1)
-  check find("xabc", re"^abc$", m, start = 1)