Consolidate Result and rank structs

By not storing item index twice, we can cut down the size of Result
struct and now it makes more sense to store and pass Results by values.
Benchmarks show no degradation of performance by additional pointer
indirection for looking up index.

1 files changed, 9 insertions, 7 deletions

diff --git a/src/pattern.go b/src/pattern.go
index 07ed9cd8..97ee8fd6 100644
--- a/src/pattern.go
+++ b/src/pattern.go
@@ -243,7 +243,7 @@ func (p *Pattern) CacheKey() string {
 }
 
 // Match returns the list of matches Items in the given Chunk
-func (p *Pattern) Match(chunk *Chunk, slab *util.Slab) []*Result {
+func (p *Pattern) Match(chunk *Chunk, slab *util.Slab) []Result {
 	// ChunkCache: Exact match
 	cacheKey := p.CacheKey()
 	if p.cacheable {
@@ -263,19 +263,19 @@ func (p *Pattern) Match(chunk *Chunk, slab *util.Slab) []*Result {
 	return matches
 }
 
-func (p *Pattern) matchChunk(chunk *Chunk, space []*Result, slab *util.Slab) []*Result {
-	matches := []*Result{}
+func (p *Pattern) matchChunk(chunk *Chunk, space []Result, slab *util.Slab) []Result {
+	matches := []Result{}
 
 	if space == nil {
 		for idx := range *chunk {
 			if match, _, _ := p.MatchItem(&(*chunk)[idx], false, slab); match != nil {
-				matches = append(matches, match)
+				matches = append(matches, *match)
 			}
 		}
 	} else {
 		for _, result := range space {
 			if match, _, _ := p.MatchItem(result.item, false, slab); match != nil {
-				matches = append(matches, match)
+				matches = append(matches, *match)
 			}
 		}
 	}
@@ -286,14 +286,16 @@ func (p *Pattern) matchChunk(chunk *Chunk, space []*Result, slab *util.Slab) []*
 func (p *Pattern) MatchItem(item *Item, withPos bool, slab *util.Slab) (*Result, []Offset, *[]int) {
 	if p.extended {
 		if offsets, bonus, pos := p.extendedMatch(item, withPos, slab); len(offsets) == len(p.termSets) {
-			return buildResult(item, offsets, bonus), offsets, pos
+			result := buildResult(item, offsets, bonus)
+			return &result, offsets, pos
 		}
 		return nil, nil, nil
 	}
 	offset, bonus, pos := p.basicMatch(item, withPos, slab)
 	if sidx := offset[0]; sidx >= 0 {
 		offsets := []Offset{offset}
-		return buildResult(item, offsets, bonus), offsets, pos
+		result := buildResult(item, offsets, bonus)
+		return &result, offsets, pos
 	}
 	return nil, nil, nil
 }