From 6711cbb69e83c6add47ca3173946483596bbca12 Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Sun, 27 Dec 2015 15:05:23 +0100
Subject: [PATCH] Added methods Head and Tail to strutil

---
 changelog.md            |  5 +++++
 strutil/strutil.go      | 30 ++++++++++++++++++++++++++++++
 strutil/strutil_test.go | 16 ++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/changelog.md b/changelog.md
index 6375bea6..9843df04 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,10 @@
 ## Changelog
 
+#### v1.3.1
+
+* `[strutil]` Added method Head for subtraction first symbols from the string
+* `[strutil]` Added method Tail for subtraction last symbols from the string
+
 #### v1.3
 
 * `[system]` Fixed major bug with OS X compatibility
diff --git a/strutil/strutil.go b/strutil/strutil.go
index 67c72010..245c04bb 100644
--- a/strutil/strutil.go
+++ b/strutil/strutil.go
@@ -80,3 +80,33 @@ func Ellipsis(s string, maxSize int) string {
 
 	return s
 }
+
+// Head return n first symbols from given string
+func Head(s string, n int) string {
+	if s == "" || n <= 0 {
+		return ""
+	}
+
+	l := len(s)
+
+	if l <= n {
+		return s
+	}
+
+	return s[:n]
+}
+
+// Tail return n last symbols from given string
+func Tail(s string, n int) string {
+	if s == "" || n <= 0 {
+		return ""
+	}
+
+	l := len(s)
+
+	if l <= n {
+		return s
+	}
+
+	return s[n:]
+}
diff --git a/strutil/strutil_test.go b/strutil/strutil_test.go
index 0e5450ec..ac87134a 100644
--- a/strutil/strutil_test.go
+++ b/strutil/strutil_test.go
@@ -49,3 +49,19 @@ func (s *StrUtilSuite) TestEllipsis(c *C) {
 	c.Assert(Ellipsis("Test1234", 8), Equals, "Test1234")
 	c.Assert(Ellipsis("Test1234test", 8), Equals, "Test1...")
 }
+
+func (s *StrUtilSuite) TestHead(c *C) {
+	c.Assert(Head("", 1), Equals, "")
+	c.Assert(Head("ABCD1234", 0), Equals, "")
+	c.Assert(Head("ABCD1234", -10), Equals, "")
+	c.Assert(Head("ABCD1234", 4), Equals, "ABCD")
+	c.Assert(Head("ABCD1234", 100), Equals, "ABCD1234")
+}
+
+func (s *StrUtilSuite) TestTail(c *C) {
+	c.Assert(Tail("", 1), Equals, "")
+	c.Assert(Tail("ABCD1234", 0), Equals, "")
+	c.Assert(Tail("ABCD1234", -10), Equals, "")
+	c.Assert(Tail("ABCD1234", 4), Equals, "1234")
+	c.Assert(Tail("ABCD1234", 100), Equals, "ABCD1234")
+}