batch

commit 2ab574a5e7687eaf12d218282d605f7bccb21f8d
parent 24897a858e52acb2d33ed5411b6e68836a4d4169
Author: Mark Wilkerson <mark@markwilkerson.me>
Date:   Tue, 20 Feb 2018 18:27:21 -0800

Initial shiz

Diffstat:
A
README.md
 | 
33
+++++++++++++++++++++++++++++++++
A
batch.go
 | 
38
++++++++++++++++++++++++++++++++++++++
A
batch_test.go
 | 
42
++++++++++++++++++++++++++++++++++++++++++

3 files changed, 113 insertions(+), 0 deletions(-)
diff --git a/README.md b/README.md
@@ -0,0 +1,33 @@
+# batch
+
+import "github.com/markhuge/batch"
+
+Batch provides helper functions for batching slices into sub slices of a
+specified length. You could think of it as pagination for slices.
+
+## Usage
+
+#### func  Str
+
+```go
+func Str(s []string, pageSize int) [][]string
+```
+Str accepts a slice of strings and a page size, then splits up the slice into
+smaller slices of length "pageSize"
+
+#### func  StrJoin
+
+```go
+func StrJoin(s []string, pageSize int, delimiter string) []string
+```
+StrJoin is a combination of Str() and strings.Join(). Rather than returning a
+slice of slices, it returns a slice of joined strings
+
+
+## Tests
+
+```
+PASS
+coverage: 100.0% of statements
+ok  	github.com/markhuge/batch	1.007s
+```
diff --git a/batch.go b/batch.go
@@ -0,0 +1,38 @@
+// Batch provides helper functions for batching slices into sub slices of a
+// specified length. You could think of it as pagination for slices.
+package batch
+
+import (
+	"math"
+	"strings"
+)
+
+// Str accepts a slice of strings and a page size, then splits up the slice
+// into smaller slices of length "pageSize"
+func Str(s []string, pageSize int) [][]string {
+
+	// math.Ceil only works properly with floats :(
+	size := int(math.Ceil(float64(len(s)) / float64(pageSize)))
+	output := make([][]string, size)
+	j := 0
+
+	for i := 0; i < len(s); i += pageSize {
+		end := i + pageSize
+		if end > len(s) {
+			end = len(s)
+		}
+		output[j] = s[i:end]
+		j++
+	}
+	return output
+}
+
+// StrJoin is a combination of Str() and strings.Join(). Rather than returning
+// a slice of slices, it returns a slice of joined strings
+func StrJoin(s []string, pageSize int, delimiter string) []string {
+	var output []string
+	for _, slice := range Str(s, pageSize) {
+		output = append(output, strings.Join(slice, delimiter))
+	}
+	return output
+}
diff --git a/batch_test.go b/batch_test.go
@@ -0,0 +1,42 @@
+package batch_test
+
+import (
+	"testing"
+
+	"github.com/markhuge/batch"
+)
+
+func TestStr(t *testing.T) {
+	input := []string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k"}
+	expected := [][]string{
+		{"a", "b", "c", "d"},
+		{"e", "f", "g", "h"},
+		{"i", "j", "k"},
+	}
+	result := batch.Str(input, 4)
+
+	for i := range result {
+		for j := range result[i] {
+			if expected[i][j] != result[i][j] {
+				t.Fatalf("Expected %s got  %s\n", expected[i][j], result[i][j])
+			}
+		}
+	}
+}
+
+func TestStrJoin(t *testing.T) {
+	input := []string{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k"}
+	expected := []string{
+		"a,b,c,d",
+		"e,f,g,h",
+		"i,j,k",
+	}
+	result := batch.StrJoin(input, 4, ",")
+
+	for i := range result {
+		if expected[i] != result[i] {
+			t.Fatalf("Expected %s, got %s", expected[i], result[i])
+		}
+	}
+
+}