collections filter functions

- FilterString() - returns all string elems
- FilterInt() - returns all int elems
- FilterBool() - returns all bool elems
- FilterFloat() - returns all float elements

collections-query.go

@@ -81,3 +81,55 @@ func (c *MiniCollections) MatchStringAll(v string) ([]string, error) {
 
 	return values, nil
 }
+
+// FilterString returns all string elements.
+func (c *MiniCollections) FilterString() []string {
+	values := []string{}
+
+	for _, i := range c.store {
+		if v, ok := i.(string); ok {
+			values = append(values, v)
+		}
+	}
+
+	return values
+}
+
+// FilterInt returns all int elements.
+func (c *MiniCollections) FilterInt() []int {
+	values := []int{}
+
+	for _, i := range c.store {
+		if v, ok := i.(int); ok {
+			values = append(values, v)
+		}
+	}
+
+	return values
+}
+
+// FilterBool returns all bool elements.
+func (c *MiniCollections) FilterBool() []bool {
+	values := []bool{}
+
+	for _, i := range c.store {
+		if v, ok := i.(bool); ok {
+			values = append(values, v)
+		}
+	}
+
+	return values
+}
+
+// FilterFloat returns all float elements (uses float64). Some integers (int) might be included.
+func (c *MiniCollections) FilterFloat() []float64 {
+	values := []float64{}
+
+	for _, i := range c.store {
+		if v, ok := i.(float64); ok {
+			values = append(values, v)
+		}
+	}
+
+	return values
+}

collections-query_test.go

@@ -1,6 +1,9 @@
 package minidb
 
-import "testing"
+import (
+	"reflect"
+	"testing"
+)
 
 func TestPush_Collections(t *testing.T) {
 	filename := "pushcols.json"
@@ -99,3 +102,31 @@ func TestMatchStringAll_Collections(t *testing.T) {
 		t.Fatal("wrong return value from match string all")
 	}
 }
+
+func TestFilter(t *testing.T) {
+	filename := "filter.json"
+	defer cleanFileAfter(filename, t)
+
+	db := NewMiniCollections(filename)
+
+	db.Push("hellox")
+	db.Push("sample")
+	db.Push(1)
+	db.Push(100)
+	db.Push(false)
+
+	frString := []string{"hellox", "sample"}
+	if !reflect.DeepEqual(db.FilterString(), frString) {
+		t.Fatal("wrong filter string output")
+	}
+
+	frInt := []int{1, 100}
+	if !reflect.DeepEqual(db.FilterInt(), frInt) {
+		t.Fatal("wrong filter int output")
+	}
+
+	frBool := []bool{false}
+	if !reflect.DeepEqual(db.FilterBool(), frBool) {
+		t.Fatal("wrong filter bool output")
+	}
+}