Cannot properly compare equal to without equality comparison functions.

Author: umpc

bounds.go

@@ -3,56 +3,12 @@ package sortedmap
 import "sort"
 
 func (sm *SortedMap) setBoundIdx(boundVal interface{}) int {
-
 	if boundVal == nil {
 		return 0
 	}
-
-	smLen := len(sm.sorted)
-	idx := sort.Search(smLen, func(i int) bool {
+	return sort.Search(len(sm.sorted), func(i int) bool {
 		return sm.lessFn(boundVal, sm.idx[sm.sorted[i]])
 	})
-
-	// sort.Search returns the smallest index i in [0, n) at which f(i) is true.
-	// This sets the correct index for less than conditional comparisons.
-	if idx > 0 {
-		idx--
-	}
-
-	return idx
-}
-
-func (sm *SortedMap) lowerBoundIncrCondition(i, j interface{}) bool {
-	return sm.lessFn(j, i)
-}
-
-func (sm *SortedMap) lowerBoundRetCondition(i, j interface{}) bool {
-	return sm.lessFn(j, i)
-}
-
-func (sm *SortedMap) upperBoundIncrCondition(i, j interface{}) bool {
-	return !sm.lessFn(j, i) && !sm.lessFn(i, j)
-}
-
-func (sm *SortedMap) upperBoundRetCondition(i, j interface{}) bool {
-	return sm.lessFn(i, j)
-}
-
-func (sm *SortedMap) adjustIdxOrReturn(boundVal interface{}, incrCondition, retCondition func(boundVal, valFromIdx interface{}) bool) (int, bool) {
-	idx := sm.setBoundIdx(boundVal)
-	if idx < len(sm.sorted)-1 {
-		valFromIdx := sm.idx[sm.sorted[idx]]
-
-		if incrCondition(boundVal, valFromIdx) {
-			idx++
-		}
-
-		valFromIdx = sm.idx[sm.sorted[idx]]
-		if retCondition(boundVal, valFromIdx) {
-			return idx, false
-		}
-	}
-	return idx, true
 }
 
 func (sm *SortedMap) boundsIdxSearch(lowerBound, upperBound interface{}) []int {
@@ -68,22 +24,23 @@ func (sm *SortedMap) boundsIdxSearch(lowerBound, upperBound interface{}) []int {
 	}
 
 	lowerBoundIdx := sm.setBoundIdx(lowerBound)
-	if lowerBound != nil {
-		var ok bool
-		lowerBoundIdx, ok = sm.adjustIdxOrReturn(lowerBound, sm.lowerBoundIncrCondition, sm.lowerBoundRetCondition)
-		if !ok {
-			return nil
-		}
+	if lowerBoundIdx == smLen {
+		lowerBoundIdx--
+	}
+	if lowerBoundIdx > 0 && sm.lessFn(sm.idx[sm.sorted[lowerBoundIdx]], lowerBound) {
+		lowerBoundIdx++
 	}
 
 	upperBoundIdx := 0
 	if upperBound == nil {
 		upperBoundIdx = smLen - 1
 	} else {
-		var ok bool
-		upperBoundIdx, ok = sm.adjustIdxOrReturn(upperBound, sm.upperBoundIncrCondition, sm.upperBoundRetCondition)
-		if !ok {
-			return nil
+		upperBoundIdx = sm.setBoundIdx(upperBound)
+		if upperBoundIdx == smLen {
+			upperBoundIdx--
+		}
+		if upperBoundIdx > 0 && sm.lessFn(upperBound, sm.idx[sm.sorted[upperBoundIdx]]) {
+			upperBoundIdx--
 		}
 	}
 

examples/README.md

@@ -147,7 +147,7 @@ func main() {
 
 ### BoundedIterCh
 
-```BoundedIterCh``` selects the records equal to or between the given bounds. Its first argument allows for reversing the order of the returned records.
+```BoundedIterCh``` selects values that are greater than the lower bound and are less than or equal to the upper bound. Its first argument allows for reversing the order of the returned records.
 
 ```go
 package main
@@ -373,7 +373,7 @@ func main() {
 
 ### BoundedDelete
 
-```BoundedDelete``` is a similar pattern as the above ```Bounded``` methods. ```BoundedDelete``` removes values that are equal to or between the provided bounds values.
+```BoundedDelete``` is a similar pattern as the above ```Bounded``` methods. ```BoundedDelete``` removes values that are greater than the lower bound and lower than or equal to the upper bound.
 
 ```go
 package main

sortedmap.go

@@ -1,11 +1,11 @@
 package sortedmap
 
-// SortedMap contains a map, a slice, and a reference to a sorting function.
+// SortedMap contains a map, a slice, and references to one or more comparison functions.
 // SortedMap is not concurrency-safe, though it can be easily wrapped by a developer-defined type.
 type SortedMap struct {
 	idx    map[interface{}]interface{}
 	sorted []interface{}
-	lessFn SortLessFunc
+	lessFn ComparisonFunc
 }
 
 // Record defines a type used in batching and iterations, where keys and values are used together.
@@ -14,27 +14,27 @@ type Record struct {
 	Val interface{}
 }
 
-// SortLessFunc defines the type of the comparison function for the chosen value type.
-type SortLessFunc func(i, j interface{}) bool
+// ComparisonFunc defines the type of the comparison function for the chosen value type.
+type ComparisonFunc func(i, j interface{}) bool
 
-func unsortedSortLessFunc(_, _ interface{}) bool {
+func noOpComparisonFunc(_, _ interface{}) bool {
 	return false
 }
 
-func setLessFunc(lessFn SortLessFunc) SortLessFunc {
-	if lessFn == nil {
-		return unsortedSortLessFunc
+func setComparisonFunc(cmpFn ComparisonFunc) ComparisonFunc {
+	if cmpFn == nil {
+		return noOpComparisonFunc
 	}
-	return lessFn
+	return cmpFn
 }
 
 // New creates and initializes a new SortedMap structure and then returns a reference to it.
 // New SortedMaps are created with a backing map/slice of length/capacity n.
-func New(n int, lessFn SortLessFunc) *SortedMap {
+func New(n int, cmpFn ComparisonFunc) *SortedMap {
 	return &SortedMap{
 		idx:    make(map[interface{}]interface{}, n),
 		sorted: make([]interface{}, 0, n),
-		lessFn: setLessFunc(lessFn),
+		lessFn: setComparisonFunc(cmpFn),
 	}
 }
 

sortedmap_test.go

@@ -23,9 +23,9 @@ func TestNew(t *testing.T) {
 	}
 }
 
-func TestUnsortedLessFunc(t *testing.T) {
+func TestNoOpFuncs(t *testing.T) {
 	if New(0, nil).lessFn(nil, nil) {
-		t.Fatal("TestUnsortedLessFunc failed: lessFn returned true!")
+		t.Fatal("TestNoOpFuncs failed: lessFn returned true!")
 	}
 }