Remove Spans interface

There is only one implementation, and given the consuming code structure in the planner it is highly likely that there will only ever be one Spans implementation.

internal/core/data.go

@@ -17,40 +17,22 @@ import (
 )
 
 // Span is a range of keys from [Start, End).
-type Span interface {
-	// Start returns the starting key of the Span.
-	Start() keys.DataStoreKey
-	// End returns the ending key of the Span.
-	End() keys.DataStoreKey
-	// Compare returns -1 if the provided span is less, 0 if it is equal, and 1 if its greater.
-	Compare(Span) SpanComparisonResult
-}
+type Span struct {
+	// Start represents the starting key of the Span.
+	Start keys.DataStoreKey
 
-type span struct {
-	start keys.DataStoreKey
-	end   keys.DataStoreKey
+	// End represents the ending key of the Span.
+	End keys.DataStoreKey
 }
 
-var _ Span = span{}
-
 // NewSpan creates a new Span from the provided start and end keys.
 func NewSpan(start, end keys.DataStoreKey) Span {
-	return span{
-		start: start,
-		end:   end,
+	return Span{
+		Start: start,
+		End:   end,
 	}
 }
 
-// Start returns the starting key of the Span.
-func (s span) Start() keys.DataStoreKey {
-	return s.start
-}
-
-// End returns the ending key of the Span.
-func (s span) End() keys.DataStoreKey {
-	return s.end
-}
-
 // SpanComparisonResult is the result of comparing two spans.
 type SpanComparisonResult uint
 
@@ -73,18 +55,18 @@ const (
 // Compares two spans returning how the compare to each other.
 // If the end of one span is adjacent to the other (with no gap possible)
 // then those ends are considered equal.
-func (this span) Compare(other Span) SpanComparisonResult {
+func (this Span) Compare(other Span) SpanComparisonResult {
 	if this == other {
 		return Equal
 	}
 
-	thisStart := this.start.ToString()
-	thisEnd := this.end.ToString()
-	otherStart := other.Start().ToString()
-	otherEnd := other.End().ToString()
+	thisStart := this.Start.ToString()
+	thisEnd := this.End.ToString()
+	otherStart := other.Start.ToString()
+	otherEnd := other.End.ToString()
 
 	if thisStart < otherStart {
-		if thisEnd == otherStart || isAdjacent(this.end, other.Start()) {
+		if thisEnd == otherStart || isAdjacent(this.End, other.Start) {
 			return StartBeforeEndEqualToStart
 		}
 
@@ -133,7 +115,7 @@ func (this span) Compare(other Span) SpanComparisonResult {
 		}
 	}
 
-	if thisStart == otherEnd || isAdjacent(this.start, other.End()) {
+	if thisStart == otherEnd || isAdjacent(this.Start, other.End) {
 		return StartEqualToEndEndAfter
 	}
 
@@ -172,7 +154,7 @@ func MergeAscending(spans []Span) []Span {
 				}
 
 				// Then we insert
-				newArray[i] = NewSpan(span.Start(), span.End())
+				newArray[i] = NewSpan(span.Start, span.End)
 
 				// Move the values prior to the new one across
 				for j := 0; j < i; j++ {
@@ -183,12 +165,12 @@ func MergeAscending(spans []Span) []Span {
 				// Exit the unique-span loop, this span has been handled
 				i = len(uniqueSpans)
 			case StartBeforeEndEqualToStart, StartBeforeEndWithin, StartBeforeEndEqual:
-				uniqueSpans[i] = NewSpan(span.Start(), uniqueSpan.End())
+				uniqueSpans[i] = NewSpan(span.Start, uniqueSpan.End)
 				uniqueSpanFound = true
 				i++
 			case StartBeforeEndAfter:
-				uniqueSpans = removeBefore(uniqueSpans, i, span.End().ToString())
-				uniqueSpans[i] = NewSpan(span.Start(), span.End())
+				uniqueSpans = removeBefore(uniqueSpans, i, span.End.ToString())
+				uniqueSpans[i] = NewSpan(span.Start, span.End)
 				uniqueSpanFound = true
 				// Exit the unique-span loop, this span has been handled
 				i = len(uniqueSpans)
@@ -197,8 +179,8 @@ func MergeAscending(spans []Span) []Span {
 				// Do nothing, span is contained within an existing unique-span
 				i = len(uniqueSpans)
 			case StartEqualEndAfter, StartWithinEndAfter, StartEqualToEndEndAfter:
-				uniqueSpans = removeBefore(uniqueSpans, i, span.End().ToString())
-				uniqueSpans[i] = NewSpan(uniqueSpan.Start(), span.End())
+				uniqueSpans = removeBefore(uniqueSpans, i, span.End.ToString())
+				uniqueSpans[i] = NewSpan(uniqueSpan.Start, span.End)
 				uniqueSpanFound = true
 				// Exit the unique-span loop, this span has been handled
 				i = len(uniqueSpans)
@@ -220,7 +202,7 @@ func MergeAscending(spans []Span) []Span {
 func removeBefore(spans []Span, startIndex int, end string) []Span {
 	indexOfLastMatchingItem := -1
 	for i := startIndex; i < len(spans); i++ {
-		if spans[i].End().ToString() <= end {
+		if spans[i].End.ToString() <= end {
 			indexOfLastMatchingItem = i
 		}
 	}