78 lines
2.1 KiB
Standard ML
78 lines
2.1 KiB
Standard ML
#!/usr/bin/env fun
|
|
|
|
/*
|
|
* This file is part of the Fun programming language.
|
|
* https://hanez.org/project/fun/
|
|
*
|
|
* Copyright 2025 Johannes Findeisen <you@hanez.org>
|
|
* Licensed under the terms of the ISC license.
|
|
* https://opensource.org/license/isc-license-txt
|
|
*/
|
|
|
|
/*
|
|
* Classes demo: fields, methods (with explicit 'this'), and usage.
|
|
*
|
|
* Notes:
|
|
* - Define a class with `class Name`
|
|
* - Fields are initialized with simple assignments inside the class body.
|
|
* - Methods are written as `fun method(this, ...) { ... }` with 'this' required as the first parameter.
|
|
* - Instantiation: p = Name()
|
|
* - Method calls: load the method function from the instance into a variable, then call it with the instance as the first argument.
|
|
* Example:
|
|
* move_fn = p["move"]
|
|
* move_fn(p, dx, dy)
|
|
*/
|
|
|
|
class Point
|
|
x = 0
|
|
y = 0
|
|
fun move(this, dx, dy)
|
|
this.x = this.x + dx
|
|
this.y = this.y + dy
|
|
return 0
|
|
fun toString(this)
|
|
return "Point(" + to_string(this.x) + ", " + to_string(this.y) + ")"
|
|
|
|
class Counter
|
|
value = 0
|
|
fun inc(this)
|
|
this.value = this.value + 1
|
|
return this.value
|
|
fun add(this, n)
|
|
this.value = this.value + n
|
|
return this.value
|
|
|
|
// Instantiate a Point
|
|
p = Point()
|
|
|
|
// Types
|
|
print("typeof(Point) = " + typeof(Point)) // Function (factory)
|
|
print("typeof(p) = " + typeof(p)) // Map (instance)
|
|
|
|
// Read/write fields
|
|
print("p.x = " + to_string(p["x"]) + ", p.y = " + to_string(p["y"]))
|
|
p["x"] = 10
|
|
p["y"] = -2
|
|
print("after set -> p.x = " + to_string(p["x"]) + ", p.y = " + to_string(p["y"]))
|
|
|
|
// Call methods by first loading them into identifiers, then passing 'p' as first argument
|
|
to_str = p["toString"]
|
|
print("toString(p) => " + to_str(p))
|
|
|
|
move_fn = p["move"]
|
|
move_fn(p, 3, 5)
|
|
print("after move(3,5) -> " + to_str(p)) // expect Point(13, 3)
|
|
|
|
// Another instance with defaults
|
|
q = Point()
|
|
print("q initially -> " + to_str(q)) // Point(0, 0)
|
|
|
|
// Counter demo
|
|
c = Counter()
|
|
inc = c["inc"]
|
|
add = c["add"]
|
|
|
|
print("counter inc -> " + to_string(inc(c))) // 1
|
|
print("counter inc -> " + to_string(inc(c))) // 2
|
|
print("counter add(5) -> " + to_string(add(c, 5))) // 7
|
|
print("counter current value = " + to_string(c["value"]))
|