Merge pull request #6149 from bep/sort-caseinsensitive

Implement lexicographically string sorting

tpl/compare/compare.go

@@ -20,18 +20,20 @@ import (
 	"strconv"
 	"time"
 
-	"github.com/gohugoio/hugo/common/types"
-
 	"github.com/gohugoio/hugo/compare"
+
+	"github.com/gohugoio/hugo/common/types"
 )
 
 // New returns a new instance of the compare-namespaced template functions.
-func New() *Namespace {
-	return &Namespace{}
+func New(caseInsensitive bool) *Namespace {
+	return &Namespace{caseInsensitive: caseInsensitive}
 }
 
 // Namespace provides template functions for the "compare" namespace.
 type Namespace struct {
+	// Enable to do case insensitive string compares.
+	caseInsensitive bool
 }
 
 // Default checks whether a given value is set and returns a default value if it
@@ -89,7 +91,10 @@ func (*Namespace) Default(dflt interface{}, given ...interface{}) (interface{},
 }
 
 // Eq returns the boolean truth of arg1 == arg2.
-func (*Namespace) Eq(x, y interface{}) bool {
+func (ns *Namespace) Eq(x, y interface{}) bool {
+	if ns.caseInsensitive {
+		panic("caseInsensitive not implemented for Eq")
+	}
 	if e, ok := x.(compare.Eqer); ok {
 		return e.Eq(y)
 	}
@@ -157,7 +162,7 @@ func (n *Namespace) Conditional(condition bool, a, b interface{}) interface{} {
 	return b
 }
 
-func (*Namespace) compareGet(a interface{}, b interface{}) (float64, float64) {
+func (ns *Namespace) compareGet(a interface{}, b interface{}) (float64, float64) {
 	if ac, ok := a.(compare.Comparer); ok {
 		c := ac.Compare(b)
 		if c < 0 {
@@ -228,6 +233,17 @@ func (*Namespace) compareGet(a interface{}, b interface{}) (float64, float64) {
 		}
 	}
 
+	if ns.caseInsensitive && leftStr != nil && rightStr != nil {
+		c := compare.Strings(*leftStr, *rightStr)
+		if c < 0 {
+			return 0, 1
+		} else if c > 0 {
+			return 1, 0
+		} else {
+			return 0, 0
+		}
+	}
+
 	switch {
 	case leftStr == nil || rightStr == nil:
 	case *leftStr < *rightStr: