play.html

@t header

<style>

#social, #sub-form, #main-header {
display: none;
}

textarea {
width: 85% !important; 
//width:400px !important; 
height: 500px; 
font-family: 'Roboto Mono'; 
font-size:13px; 
//margin-top:20px; 
padding: 5px; 
    border: none;
    outline: none; 

background-color:#f5f5f5; 
} 
.menu {
//height: auto; 
} 
button {
width: 80px; 
font-size:20px; 
} 
.controls {
padding-top:20px ; 
height:40px; 
} 
.example {
display:none; 
} 
.center {
max-width:1070px !important; 
} 
#status {
color:#777; 
font-size: 80%; 
font-family: 'Roboto Mono'; 
margin-top: 10px; 
} 

.output {
font-family: 'Roboto Mono'; 
 
} 

.buttons button {
height: 30px; 
font-size:14px; 
margin-bottom:10px; 
width: 100%; 
} 
.lines {
//position:relative;
padding-top:5px; 
float:left; 
font-size:13px;
color:#aaa; 
text-align:right; 
background-color:#f5f5f5; 
} 
.lines div { 
} 

	@@media (max-width: 1500px) {
#social-extra {
display:none !important; 
} 
} 

</style> 

<script  src="/js/jquery.min.js"></script> 
<script src="/js/jquery-linedtextarea.js"></script> 


<script>


var ip = 'play3.vlang.io' 
function run() {
	var body = $('textarea').val(); 
	$('.controls').css('visibility', 'hidden'); 
	$('.output').text('Waiting for remote server...') 
	$('#status').text('') 
	var http = 'https://';
	if (!ip.includes('play')) {
		http = 'http://'; 
	} 
	console.log(http + ip + '/compile') 
	$.post(http + ip + '/compile', {body:body}, function(resp) {
		console.log(resp) 
		var vals = resp.split('==vmft:') 
		console.log(vals) 
		$('.output').text(vals[0]); 
	$('.controls').css('visibility', 'visible'); 
		if (vals.length > 1){ 
		var fmt = vals[1]; 
		if (fmt != '') { 
			$('textarea').val(fmt); 
		} 
		$('#status').text('Program exited.') 
	} 
} ); 
 
} 

function select_ex(id ) { 
	var text = $('#ex' + id).text()
	$('textarea').val(text) 
} 

$(document).ready(function() {
$("a:contains(Playground)").css('font-weight', '500') 
			$('#code').linedtextarea();

	var s = localStorage.getItem('play') 
	if (s != '') { 
		$('textarea').val(s) 
		localStorage.setItem('play', '') 
	} 

	document.addEventListener('keyup', doc_keyUp, false); 

}); 


function doc_keyUp(e) {
    if (e.ctrlKey && e.keyCode == 13) {
	run() 
    }
}

</script> 



<div class='center'> 
<p> 
<!-- 
Due to inconsitencies between the documentation and this pre-alpha build,
the playground has been disabled until a more stable release and an updated documentation. 
--> 
<p> 

</div> 
<div class='center'>
<div class='controls' style='height:100px'> 
<!--
<button id=btnRun onclick='run()' >Run</button> 
<span style='font-size:80%; margin-left:10px; color:#444;'> 
(or press Ctrl + Enter to run the program) 
-->
back soon
<!--
The playground is temporarily offline. It will be back soon. <br> In the meantime you can install V on your machine in a couple of seconds.
<br>
Or use an alternative playground Judge0: <a target=_blank href='https://vlang.ide.judge0.com'>https://vlang.ide.judge0.com</a>.
</span> 
-->
<!-- 
The playground will be back today (moving to a new server) 
--> 
<!--
<span style='float:right; font-size:80%;line-height:40px'>Your code will be formatted automatically</span> 
</div> 
--> 


<div style='float:right; width:210px; margin-top:20px' class='buttons'> 
<button onclick='select_ex(0)'>Hello world</button> 
<button onclick='select_ex(1)'>Fibonacci</button> 
<button onclick='select_ex(2)'>Fibonacci + memoization</button> 
<button onclick='select_ex(3)'>JSON decoding/encoding</button> 
<button onclick='select_ex(4)'>Users repo + option types</button> 
<button onclick='select_ex(5)'>Advanced consts</button> 
<button onclick='select_ex(6)'>Basic operator overloading</button> 
<button onclick='select_ex(7)'>An updated copy of a struct</button> 

<br> 
<a target=_blank href='/docs'>Check out the docs for more examples</a> 
</div> 

<div style='height:505px; max-height:505px;'> 
<textarea id='code' autocorrect="off" autocomplete="off" autocapitalize="off" spellcheck="false">fn main() {
	areas := ['game', 'web', 'tools', 'science', 'systems', 'GUI', 'mobile']
        for area in areas {
                println('Hello, $area developers!')
        }
} 
</textarea> 
</div> 

<pre class='example' id='ex0' >fn main() { 
	areas := ['game', 'web', 'tools', 'science', 'systems', 'GUI', 'mobile']
        for area in areas {
                println('Hello, $area developers!')
        }
} 
</pre> 
<pre class='example' id='ex1'>fn fib(n int) int {
        if n <= 1 {
                return n
        }
        return fib(n - 1) + fib(n - 2)
}

fn main() {
        for i := 0; i < 10; i++ {
                println(fib(i))
        }
}
</pre> 
<pre class='example' id=ex2>const (
        MAX = 15 
)

struct Fib {
        nums []int
}

fn (fib mut Fib) calc(n int) int {
        if n <= 1 {
                return n
        }
        if fib.nums[n] != 0 {
                return fib.nums[n]
        }
        fib.nums[n] = fib.calc(n - 1) + fib.calc(n - 2)
        return fib.nums[n]
}

fn main() {
        mut fib := Fib {
                nums: [0; MAX]
        }
        for i := 0; i < MAX; i++ {
                println(fib.calc(i))
        }
}
</pre> 

<pre class='example' id=ex3>import json

struct User {
	name          string
	age           int
mut: 
	is_registered bool
}

fn main() {
	s := '[{ "name":"Frodo", "age":25}, {"name":"Bobby", "age":10}]'
	users := json.decode( []User, s) or {
		eprintln('Failed to parse json')
		return 
	}
	for user in users {
		println('$user.name: $user.age')
	}
	println('')
	for i, user in users {
		println('$i) $user.name')
		if !user.can_register() {
			println('Cannot register $user.name, they are too young')
			continue 
		}
		users[i].register() // `user` is immutable, we have to modify the array 
	}
	// Let's encode users again just for fun
	println('')
	println(json.encode(users))
}

fn (u User) can_register() bool {
        return u.age >= 16
}

fn (u mut User) register() {
        u.is_registered = true
}
</pre> 

<pre class='example' id=ex4>struct User {
	id   int
	name string
}

struct Repo {
	users []User
}

fn new_repo() Repo {
	return Repo {
		users: [User{1, 'Andrew'}, User {2, 'Bob'}, User {10, 'Charles'}]
	}
}

fn (r Repo) find_user_by_id(id int) User? {
	for user in r.users {
		if user.id == id {
			// V automatically wraps this into an option type
			return user
		}
	}
	return error('User $id not found')
}

fn main() {
	repo := new_repo()
	// Option types must be handled by `or` blocks
	user := repo.find_user_by_id(10) or {
		// `or` block must end with `return`, `break`, or `continue`
		println('not found')
		return
	}
	println(user.id) // ==> '10'
	println(user.name) // ==> 'Charles'
}
</pre> 

<pre class='example' id=ex5>struct Color {
        r int
        g int
        b int
}

fn (c Color) str() string {
	return '{$c.r, $c.g, $c.b}' 
} 

fn rgb(r, g, b int) Color { 
	return Color{r: r, g: g, b: b}
} 

const (
        NUMBERS = [1, 2, 3]

        RED  = Color{r: 255, g: 0, b: 0}
        BLUE = rgb(0, 0, 255)
)

fn main() {
        println(NUMBERS)
        println(RED)
        println(BLUE)
}  
</pre> 


<pre class='example' id=ex6>struct Vec {
	x int
	y int
}

fn (a Vec) str() string {
	return '{$a.x, $a.y}'
}

fn (a Vec) + (b Vec) Vec {
	return Vec {
		a.x + b.x,
		a.y + b.y
	}
}

fn (a Vec) - (b Vec) Vec {
	return Vec {
		a.x - b.x,
		a.y - b.y
	}
}

fn main() {
	a := Vec{2, 3}
	b := Vec{4, 5}
	println(a + b) 
	println(a - b) 
}
</pre> 


<pre class='example' id=ex7>struct User {
	name string
	age  int	 
} 

fn main() { 
	user1 := User{'Bob', 20} 
	user2 := { user1 | name: 'Peter' } 
	println(user1.name)
	println(user1.age)
	println(user2.name) 
	println(user2.age)
} 
</pre> 

<pre class='output'> 
This is an alpha stage, please report all issues via GitHub. 

For security reasons, imports are temporarily disabled, the size of the program
is limited, and your program can't run for more than 1 second. 





</pre> 
<span id='status'></span> 
</div> 

@t footer