prelude.lua
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local function push(self, value)
self.n = self.n + 1
table.insert(self, value)
end
local function pop(self)
local value = self[self.n]
self[self.n] = nil
self.n = self.n - 1
return value
end
local function peek(self)
return self[self.n]
end
local function create_stack(object, name)
object[name] = { n = 0 , push = push, pop = pop, peek = peek }
end
LOBBY = {}
create_stack(LOBBY, "lobby")
LOBBY["lobby"]:push(LOBBY)
function PUSH(stack, value)
if not LOBBY[stack] then create_stack(LOBBY, stack) end
LOBBY[stack]:push(value)
end
function PEEK(stack)
assert(LOBBY[stack], "Stack underflow")
assert(LOBBY[stack].n > 0, "Stack underflow")
return LOBBY[stack]:peek()
end
function POP(stack)
assert(LOBBY[stack], "Stack underflow")
assert(LOBBY[stack].n > 0, "Stack underflow")
return LOBBY[stack]:pop()
end
function PUSHTO(object, stack, value)
if not object[stack] then
create_stack(object, stack)
end
object[stack]:push(value)
end
function POPFROM(object, stack)
assert(object[stack], "Stack underflow in external object.")
assert(object[stack].n > 0, "Stack underflow in external object.")
return object[stack]:pop()
end
function _become()
LOBBY = POP('')
end
function _me()
PUSH('', LOBBY)
end
function _object()
PUSH('', {})
end
| 1 | local function push(self, value) |
| 2 | self.n = self.n + 1 |
| 3 | table.insert(self, value) |
| 4 | end |
| 5 | |
| 6 | local function pop(self) |
| 7 | local value = self[self.n] |
| 8 | self[self.n] = nil |
| 9 | self.n = self.n - 1 |
| 10 | return value |
| 11 | end |
| 12 | |
| 13 | local function peek(self) |
| 14 | return self[self.n] |
| 15 | end |
| 16 | |
| 17 | local function create_stack(object, name) |
| 18 | object[name] = { n = 0 , push = push, pop = pop, peek = peek } |
| 19 | end |
| 20 | |
| 21 | LOBBY = {} |
| 22 | create_stack(LOBBY, "lobby") |
| 23 | LOBBY["lobby"]:push(LOBBY) |
| 24 | |
| 25 | function PUSH(stack, value) |
| 26 | if not LOBBY[stack] then create_stack(LOBBY, stack) end |
| 27 | LOBBY[stack]:push(value) |
| 28 | end |
| 29 | |
| 30 | function PEEK(stack) |
| 31 | assert(LOBBY[stack], "Stack underflow") |
| 32 | assert(LOBBY[stack].n > 0, "Stack underflow") |
| 33 | return LOBBY[stack]:peek() |
| 34 | end |
| 35 | |
| 36 | function POP(stack) |
| 37 | assert(LOBBY[stack], "Stack underflow") |
| 38 | assert(LOBBY[stack].n > 0, "Stack underflow") |
| 39 | return LOBBY[stack]:pop() |
| 40 | end |
| 41 | |
| 42 | function PUSHTO(object, stack, value) |
| 43 | if not object[stack] then |
| 44 | create_stack(object, stack) |
| 45 | end |
| 46 | object[stack]:push(value) |
| 47 | end |
| 48 | |
| 49 | function POPFROM(object, stack) |
| 50 | assert(object[stack], "Stack underflow in external object.") |
| 51 | assert(object[stack].n > 0, "Stack underflow in external object.") |
| 52 | return object[stack]:pop() |
| 53 | end |
| 54 | |
| 55 | function _become() |
| 56 | LOBBY = POP('') |
| 57 | end |
| 58 | |
| 59 | function _me() |
| 60 | PUSH('', LOBBY) |
| 61 | end |
| 62 | |
| 63 | function _object() |
| 64 | PUSH('', {}) |
| 65 | end |
| 66 |