49 lines
933 B
Standard ML
49 lines
933 B
Standard ML
#!/usr/bin/env fun
|
|
|
|
// Objects as maps: nested fields, methods with explicit self
|
|
|
|
// A method to move a 2D point by dx, dy
|
|
fun move(self, dx, dy)
|
|
self["x"] = self["x"] + dx
|
|
self["y"] = self["y"] + dy
|
|
return 0
|
|
|
|
// Create a point directly and inspect fields
|
|
p = { "x": 1, "y": 2, "move": move }
|
|
print(p["x"]) // -> 1
|
|
print(p["y"]) // -> 2
|
|
|
|
// Update a field directly
|
|
p["x"] = 10
|
|
print(p["x"]) // -> 10
|
|
|
|
// Call method with explicit self
|
|
move(p, 3, -2)
|
|
print(p["x"]) // -> 13
|
|
print(p["y"]) // -> 0
|
|
|
|
// Nested object example
|
|
rect = {
|
|
"pos": { "x": 0, "y": 0 },
|
|
"size": { "w": 5, "h": 4 }
|
|
}
|
|
print(rect["pos"]["x"]) // -> 0
|
|
print(rect["size"]["w"]) // -> 5
|
|
|
|
// Mutate nested fields
|
|
rect["pos"]["x"] = rect["pos"]["x"] + 7
|
|
rect["size"]["h"] = rect["size"]["h"] + 1
|
|
print(rect["pos"]["x"]) // -> 7
|
|
print(rect["size"]["h"]) // -> 5
|
|
|
|
/* Expected output:
|
|
1
|
|
2
|
|
10
|
|
13
|
|
0
|
|
0
|
|
5
|
|
7
|
|
5
|
|
*/
|