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Introduction to
Go LanguageGDG DEVFEST BAGUIO - CAR 2014
UNIVERSITY OF BAGUIO
TZAR C. UMANG
ICT DIRECTOR – HIVE INC.
Flow of discussion
Requirements
Introduction
Basics
Sample Deployment
Requirements
Development
Software Development Kit and Test Environment
You can use Appengine’s Go SDK:
https://cloud.google.com/appengine/downloads
Python 2.7 (please don’t use the newest version)
IDE
You can use Sublimetxt and notepad++
If your on the cloud you can use Github’s online IDE
Pushing files when Deploying
Git: http://git-scm.com
Requirements
Development Servers
Highly recommend Google’s Appengine for Go Language
You can also use Openshift’s Go Language Environment, but you will
not have access to Appengine’s functionalities
Deployment
You can use Appengine + Cloudcompute of Google
Or Openshift Big Gear
Young Language
Created by: Robert Griesemer, Ken Thompson,
and Rob Pike (Googlers) in late 2007
Brought to public in 2009A new systems programming language for the
past 10 years +
It is fast to develop, compile and run
Answer to hardware’s limitations today, yet future proofing your system,
where the language handles routine and memory management
Fun and Easy making development more productive
and we don’t use semicolons “;”
Uses goroutines, a lightweight communicating processes and its
concurrent, multiplexing of it onto threads is done automatically
Has a good garbage collection, it is efficient and low in latency
Basics - “Hello World”
package helloworld
import (
"fmt""net/http" //http handler package
)
func init() {
http.HandleFunc("/", handle)
}
func handle(w http.ResponseWriter, r *http.Request) {fmt.Fprint(w, "<html><body><b>Hello World</b></body></html>")
}
Basics
Comments
Uses /**/ or //
// for line by line comment
/**/ for large chunk disabling of function or a big header credit on your code
Basics
Formatting
Indention is just like any other IDE for any PL tab works for them
gofmt handles alignment on you code
Parenthesis
Go uses lesser parenthesis
Structures like if, for and switch don’t require it
Operator precedence hierarchy is shorter and clearer
x<<8 + y<<16 //spaces implies what it means
Basics
Semicolons “ ; “
We don’t usually use it to terminate a line just like python
Mostly used to separate clauses of for – loops and the like
Making codes cleaner on the eye
Basics
If – statement
It looks as simple as this
if a > 1 {
return b
}
It also accept initialization statements, to setup a local variable
if err := datastore.Get(c, key, &b); err != nil {
return err
}
Basics
Loop
Unified for and while, there is no do-while
For
for init; condition; post { }
While
for condition { }
For(;;)
for { }
No comma operator and “+ +” and “- -” are statements not expression
// Reverse a
for i, j := 0, len(a)1; i < j; i, j = i+1, j1 {
a[i], a[j] = a[j], a[i]
}
To run multiple variables you need to use assignments
Basics
Switch
Go uses a more general implementation of switches
Expressions don’t need to be constants or even integers
Cases are evaluated top to bottom until a match is found
And if switch has no statement it switches to “true”
Making it possible to write if-else-if-else-if-else chain as a switch
Basics
Switch
func unhex(c byte) byte {
switch {
case '0' <= c && c <= '9':
return c '0'
case 'a' <= c && c <= 'f':
return c 'a' + 10
case 'A' <= c && c <= 'F':
return c 'A' + 10
}
return 0
}
Basics
Switch
Cases can be presented into commas as well
func runOver(c byte) bool {
switch c {
case ' ', '?', '&', '=', '#', '+', '%':
return true
}
return false
}
Basics
Types
It uses the regular int, float, string
Booleans (&& “and”, || “or”, ! “not”)
Explicitly sized types the likes of int8, float64
Unsigned integers, uint, uint32
Basics
Strings
It is built in, these are immutable values not just arrays of bytes values.
You can’t change a string variable once it is built
Though you can use snippets to change or to reassign string variables
s := "hello"
if s[1] != 'e' { os.Exit(1) }
s = "good bye"
var p *string = &s
*p = "ciao"
Basics
Arrays
Declared this way
var arrayOfInt [10]int;
They are like strings with values though mutable
Arrays holds values in Go making it as meaningful as a string, not like
with other language such as C where arrays are pointers
Basics
Pointers
We have them but they are limited
No pointer arithmetic
Easier for garbage collection
Basics
Database supported
MySQL, Oracle, DB2
MongoDB, NoSQL
Mobile App Delivery Supported Platform and Framework (Based on
our testing)
Intel XDK
Phonegap
Basics
Libraries
OS, I/O, files
math (sin(x) etc.)
strings, Unicode, regular expressions
reflection
command-line flags, logging
hashes, crypto
testing (plus testing tool, gotest)
networking, HTTP, RPC
HTML (and more general) templates
And growing…
Documentation and complete list here: http://golang.org
Other Resources
http://golang.org/pkg/ (package docs)
http://golang.org/src/ (source code)
Requirements
Development
Software Development Kit
You can use Appengine’s Go SDK:
https://cloud.google.com/appengine/downloads
Python 2.7 (please don’t use the newest version)
IDE
You can use Sublimetxt and notepad++
If your on the cloud you can use Github’s online IDE
Pushing files
Git: http://git-scm.com
Requirements
Development Servers
Highly recommend Google’s Appengine for Go Language
You can also Openshift’s Go Language Environment, but you will not
have access to Appengine’s functionalities
Deployment
You can use Appengine + Cloudcompute of Google
Or Openshift Big Gear
THANK YOU!!!
For Questions and Tutorials you may join the group
“Philippine Gophers” in FB and G+
Or add me in:
fb.com/tzarumang
twitter.com/definitelytzar
plus.google.com/tzarumang
Presentation is based from:golang.org
Chris Lupo’s The Go Programming Language
