Rename method receivers from 'regex' to 're' (it's shorter)

regex/compile.go

@@ -22,17 +22,17 @@ type Reg struct {
 
 // NumSubexp returns the number of sub-expressions in the given [Reg]. This is equivalent
 // to the number of capturing groups.
-func (r Reg) NumSubexp() int {
-	return r.numGroups
+func (re Reg) NumSubexp() int {
+	return re.numGroups
 }
 
 // String returns the string used to compile the expression.
-func (r Reg) String() string {
-	return r.str
+func (re Reg) String() string {
+	return re.str
 }
 
-func (r Reg) Longest() {
-	r.preferLongest = true
+func (re *Reg) Longest() {
+	re.preferLongest = true
 }
 
 const concatRune rune = 0xF0001