From e4f0311afa1c4547cfcd26555d1b7ac558a7789a Mon Sep 17 00:00:00 2001
From: magical <magical@tilde.town>
Date: Sun, 23 Jan 2022 05:38:36 +0000
Subject: [PATCH] change collision back to a pointer type

this is better for inplace_insert
---
 pmap.go | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/pmap.go b/pmap.go
index 9f7183d..88ff72d 100644
--- a/pmap.go
+++ b/pmap.go
@@ -100,7 +100,7 @@ func (n *node) getNode(shift, hash uint32, key Key) interface{} {
 	return n.child[n.index(m)]
 }
 
-func (n collision) getNode(hash uint32, key Key) interface{} {
+func (n *collision) getNode(hash uint32, key Key) interface{} {
 	if hash != n.hash {
 		return nil
 	}
@@ -128,7 +128,7 @@ func lookup(root interface{}, hash uint32, key Key, zero Value) (Value, bool) {
 		case *node:
 			cur = n.getNode(shift, hash, key)
 			shift += nodeShift
-		case collision:
+		case *collision:
 			cur = n.getNode(hash, key)
 		default:
 			panic("pmap: unhandled case in lookup")
@@ -168,7 +168,7 @@ func insert(n interface{}, hash uint32, key Key, val Value, hashFn HashFunc) (ne
 			} else if h := hashFn(n.k); h == hash {
 				// collision
 				added = true
-				return collision{hash, []leaf{{key, val}, n}}
+				return &collision{hash, []leaf{{key, val}, n}}
 			} else {
 				if h>>shift == hash>>shift {
 					panic("pmap: infinite loop in insert")
@@ -206,7 +206,7 @@ func insert(n interface{}, hash uint32, key Key, val Value, hashFn HashFunc) (ne
 				x.check()
 				return x
 			}
-		case collision:
+		case *collision:
 			if n.hash != hash {
 				// not a collision, so we must still have some hash bits left
 				// split the trie
@@ -221,12 +221,12 @@ func insert(n interface{}, hash uint32, key Key, val Value, hashFn HashFunc) (ne
 					copy(l[1:], n.leaf[:i])
 					copy(l[1+i:], n.leaf[i+1:])
 					added = false
-					return collision{hash, l}
+					return &collision{hash, l}
 				}
 			}
 			// new collision
 			added = true
-			return collision{hash, append([]leaf{{key, val}}, n.leaf...)}
+			return &collision{hash, append([]leaf{{key, val}}, n.leaf...)}
 		default:
 			panic("pmap: unhandled case in insert")
 		}
@@ -272,7 +272,7 @@ func (p pmap) stats() stats {
 					s.emptySlots++
 				}
 			}
-		case collision:
+		case *collision:
 			s.count++
 			s.collisionCount++
 			s.collidedKeys += len(n.leaf)