From 9e12f9dcb32199b23efbd0c7e954daa3c962e1ea Mon Sep 17 00:00:00 2001
From: Aadhavan Srinivasan <aadhavan@twomorecents.org>
Date: Sun, 9 Feb 2025 15:38:26 -0500
Subject: [PATCH] Added field to Reg, denoting if we prefer longest match
 (POSIX style) or not (perl style)

---
 regex/compile.go | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/regex/compile.go b/regex/compile.go
index 9a703b9..da733de 100644
--- a/regex/compile.go
+++ b/regex/compile.go
@@ -14,9 +14,10 @@ var notDotChars []rune
 // the startState of the NFA representation of the regex, and the number of capturing
 // groups in the regex. It also contains the expression string.
 type Reg struct {
-	start     *nfaState
-	numGroups int
-	str       string
+	start         *nfaState
+	numGroups     int
+	str           string
+	preferLongest bool
 }
 
 // NumSubexp returns the number of sub-expressions in the given [Reg]. This is equivalent
@@ -30,6 +31,10 @@ func (r Reg) String() string {
 	return r.str
 }
 
+func (r Reg) Longest() {
+	r.preferLongest = true
+}
+
 const concatRune rune = 0xF0001
 
 // Flags for shuntingYard - control its behavior
@@ -1135,7 +1140,7 @@ func thompson(re []postfixNode) (Reg, error) {
 	concatenate(nfa[0], &lastState)
 
 	// The string is empty here, because we add it in Compile()
-	return Reg{nfa[0], numGroups, ""}, nil
+	return Reg{nfa[0], numGroups, "", false}, nil
 
 }