From c9f3a59969864ce4680f62c7389e777be8e67ede Mon Sep 17 00:00:00 2001
From: Nikita Tokarchuk <tokarchuk+bitbucket@nevisq.com>
Date: Thu, 7 Feb 2019 23:47:46 +0100
Subject: [PATCH] Split compose applier

---
 mongox/query/compose.go | 46 +++++++++++++++++++++++++++--------------
 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/mongox/query/compose.go b/mongox/query/compose.go
index 2639437..e529b58 100644
--- a/mongox/query/compose.go
+++ b/mongox/query/compose.go
@@ -14,7 +14,9 @@ func Compose(filters ...interface{}) *Query {
 
 		ok := false
 		ok = ok || applyBson(q, f)
-		ok = ok || applyLimits(q, f)
+		ok = ok || applyLimit(q, f)
+		ok = ok || applySort(q, f)
+		ok = ok || applySkip(q, f)
 
 		if !ok {
 			panic(errors.InternalErrorf("unknown filter %v", f))
@@ -27,29 +29,43 @@ func Compose(filters ...interface{}) *Query {
 // applyBson is a fallback for a custom bson.M
 func applyBson(q *Query, f interface{}) bool {
 
-	switch f := f.(type) {
-	case bson.M:
+	if f, ok := f.(bson.M); ok {
 		q.And(f)
-	default:
-		return false
+		return true
 	}
 
-	return true
+	return false
 }
 
-// applyLimits extends query with contol functions
-func applyLimits(q *Query, f interface{}) bool {
+// applyLimits extends query with a limiter
+func applyLimit(q *Query, f interface{}) bool {
 
-	switch f := f.(type) {
-	case Limiter:
+	if f, ok := f.(Limiter); ok {
 		q.limiter = f
-	case Sorter:
+		return true
+	}
+
+	return false
+}
+
+// applySort extends query with a sort rule
+func applySort(q *Query, f interface{}) bool {
+
+	if f, ok := f.(Sorter); ok {
 		q.sorter = f
-	case Skipper:
+		return true
+	}
+
+	return false
+}
+
+// applySkip extends query with a skip number
+func applySkip(q *Query, f interface{}) bool {
+
+	if f, ok := f.(Skipper); ok {
 		q.skipper = f
-	default:
-		return false
+		return true
 	}
 
-	return true
+	return false
 }