add: slice expressions

15-slices/08-slice-expressions/1-theory/main.go

@@ -0,0 +1,38 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	s "github.com/inancgumus/prettyslice"
+)
+
+func main() {
+	msg := []byte{'h', 'e', 'l', 'l', 'o'}
+	s.Show("msg", msg)
+
+	s.Show("msg[0:1]", msg[0:1])
+	s.Show("msg[0:2]", msg[0:2])
+	s.Show("msg[0:3]", msg[0:3])
+	s.Show("msg[0:4]", msg[0:4])
+	s.Show("msg[0:5]", msg[0:5])
+
+	// default indexes
+	s.Show("msg[0:]", msg[0:])
+	s.Show("msg[:5]", msg[:5])
+	s.Show("msg[:]", msg[:])
+
+	// error: beyond
+	// s.Show("msg", msg)[:6]
+
+	s.Show("msg[1:4]", msg[1:4])
+
+	s.Show("msg[1:5]", msg[1:5])
+	s.Show("msg[1:]", msg[1:])
+
+	s.Show("append(msg)", append(msg[:4], '!'))
+}

15-slices/08-slice-expressions/2-example/main.go

@@ -0,0 +1,59 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+
+	s "github.com/inancgumus/prettyslice"
+)
+
+func main() {
+	// think of this as search results of a search engine.
+	// it could have been fetched from a database
+	items := []string{
+		"pacman",
+		"mario",
+		"tetris",
+		"doom",
+		"galaga",
+		"frogger",
+		"asteroids",
+		"simcity",
+		"metroid",
+		"defender",
+		"rayman",
+		"tempest",
+		"ultima",
+	}
+
+	s.MaxPerLine = 4
+	s.Show("All items", items)
+
+	top3 := items[:3]
+	s.Show("Top 3 items", top3)
+
+	l := len(items)
+
+	// you can use variables in a slice expression
+	last4 := items[l-4:]
+	s.Show("Last 4 items", last4)
+
+	// reslicing: slicing another sliced slice
+	mid := last4[1:3]
+	s.Show("Last4[1:3]", mid)
+
+	// the same elements can be in different indexes
+	// fmt.Println(items[9], last4[0])
+
+	// slicing returns a slice with the same type of the sliced slice
+	fmt.Printf("slicing : %T %[1]q\n", items[2:3])
+
+	// indexing returns a single element with the type of the indexed slice's element type
+	fmt.Printf("indexing: %T %[1]q\n", items[2])
+}

15-slices/09-slice-expressions-pagination/main.go

@@ -0,0 +1,49 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+
+	s "github.com/inancgumus/prettyslice"
+)
+
+func main() {
+	// think of this as search results of a search engine.
+	// it could have been fetched from a database
+	items := []string{
+		"pacman", "mario", "tetris", "doom",
+		"galaga", "frogger", "asteroids", "simcity",
+		"metroid", "defender", "rayman", "tempest",
+		"ultima",
+	}
+
+	// s.Show("0:4", items[0:4])
+	// s.Show("4:8", items[4:8])
+	// s.Show("8:12", items[8:12])
+	// s.Show("12:13", items[12:13])
+	// s.Show("12:14", items[12:14]) // error
+
+	l := len(items)
+
+	const pageSize = 4
+
+	for from := 0; from < l; from += pageSize {
+		to := from + pageSize
+		if to > l {
+			to = l
+		}
+
+		// fmt.Printf("%d:%d\n", from, to)
+
+		currentPage := items[from:to]
+
+		head := fmt.Sprintf("Page #%d", (from/pageSize)+1)
+		s.Show(head, currentPage)
+	}
+}