From af23793a57f2436814052d120310d6edba3415d5 Mon Sep 17 00:00:00 2001
From: TheBoringDude <iamcoderx@gmail.com>
Date: Sun, 30 May 2021 22:11:24 +0800
Subject: [PATCH] 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      | 52 +++++++++++++++++++++++++++++++++++++++
 collections-query_test.go | 33 ++++++++++++++++++++++++-
 2 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/collections-query.go b/collections-query.go
index 696aa5a..a766670 100644
--- a/collections-query.go
+++ b/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
+}
diff --git a/collections-query_test.go b/collections-query_test.go
index 0b6ff0c..17784f4 100644
--- a/collections-query_test.go
+++ b/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")
+	}
+}