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| 1 | namespace Source is | |
| 2 | class LOCATION_STACK is | |
| 3 | _stack: Collections.STACK[LOCATION] | |
| 4 | ||
| 5 | init() is | |
| 6 | _stack = Collections.STACK[LOCATION]() | |
| 7 | si | |
| 8 | ||
| 9 | is_empty: bool => _stack.count == 0 | |
| 10 | ||
| 11 | current: LOCATION? => | |
| 12 | if _stack.count > 0 then | |
| 13 | _stack.peek() | |
| 14 | else | |
| 15 | null | |
| 16 | fi | |
| 17 | ||
| 18 | push(location: LOCATION) is | |
| 19 | _stack.push(location) | |
| 20 | si | |
| 21 | ||
| 22 | pop() is | |
| 23 | assert _stack.count > 0 | |
| 24 | _stack.pop() | |
| 25 | si | |
| 26 | si | |
| 27 | si |