Module:FunList/Iterators: Difference between revisions
From Melvor Idle
m (Ricewind moved page Module:FunList/StateMachine to Module:FunList/Enumerators without leaving a redirect) |
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enumerable = {} | -- BASE ENUMERATOR CLASS -- | ||
local | --enumerable = {} | ||
local | local Enumerator = {} | ||
__index = | local Enumerator_mt = { | ||
__index = Enumerator, | |||
__pairs = function(t) return t:overridePairs()end | __pairs = function(t) return t:overridePairs()end | ||
} | } | ||
function | function Enumerator.new() | ||
local self = setmetatable({}, | local self = setmetatable({}, Enumerator_mt) | ||
self.current = nil | self.current = nil | ||
self.index = nil | self.index = nil | ||
Line 15: | Line 14: | ||
end | end | ||
function | function Enumerator:moveNext() | ||
error('Not implemented in base class.') | |||
end | end | ||
function | function Enumerator:overridePairs() | ||
self.index = nil | self.index = nil | ||
self.current = nil | self.current = nil | ||
Line 44: | Line 32: | ||
end | end | ||
return | -- TABLE ENUMERATOR CLASS -- | ||
-- This is essentially a wrapper for the table object, | |||
-- since it provides no state machine esque iteration out of the box | |||
local TableEnumerator = setmetatable({}, { __index = Enumerator }) | |||
TableEnumerator.__index = TableEnumerator | |||
function TableEnumerator.new(tbl) | |||
local self = setmetatable(Enumerator.new(), TableEnumerator) | |||
self.data = tbl | |||
return self | |||
end | |||
function TableEnumerator:moveNext() | |||
-- Grab the next index for the internal table. | |||
local key = self.index | |||
key = next(self.data, key) | |||
self.index = key | |||
-- If the index exist, we have succesfuly moved to the next. | |||
if key then | |||
self.current = self.data[key] | |||
return true | |||
end | |||
return false | |||
end | |||
return { | |||
Enumerator = Enumerator, | |||
TableEnumerator = TableEnumerator | |||
} |
Revision as of 15:26, 21 July 2024
Documentation for this module may be created at Module:FunList/Iterators/doc
-- BASE ENUMERATOR CLASS --
--enumerable = {}
local Enumerator = {}
local Enumerator_mt = {
__index = Enumerator,
__pairs = function(t) return t:overridePairs()end
}
function Enumerator.new()
local self = setmetatable({}, Enumerator_mt)
self.current = nil
self.index = nil
return self
end
function Enumerator:moveNext()
error('Not implemented in base class.')
end
function Enumerator:overridePairs()
self.index = nil
self.current = nil
local function iterator(t, k)
if self:moveNext() == true then
return self.index, self.current
else
return nil, nil
end
end
return iterator, self, nil
end
-- TABLE ENUMERATOR CLASS --
-- This is essentially a wrapper for the table object,
-- since it provides no state machine esque iteration out of the box
local TableEnumerator = setmetatable({}, { __index = Enumerator })
TableEnumerator.__index = TableEnumerator
function TableEnumerator.new(tbl)
local self = setmetatable(Enumerator.new(), TableEnumerator)
self.data = tbl
return self
end
function TableEnumerator:moveNext()
-- Grab the next index for the internal table.
local key = self.index
key = next(self.data, key)
self.index = key
-- If the index exist, we have succesfuly moved to the next.
if key then
self.current = self.data[key]
return true
end
return false
end
return {
Enumerator = Enumerator,
TableEnumerator = TableEnumerator
}