102 lines
2.0 KiB
Lua
Executable File
102 lines
2.0 KiB
Lua
Executable File
require 'tuple'
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class.Set()
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function Set:__init(...) -- Construct with initial elements
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local arg = {...}
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self.elem = {}
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self.n = #arg
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for i, v in ipairs(arg) do self.elem[v] = true end
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end
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function Set:__tostring() -- String representation
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local function ascii(e)
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return type(e) == 'string' and string.format('%q', e) or tostring(e)
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end
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local s = ''
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for e in pairs(self.elem) do
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s = #s == 0 and ascii(e) or s .. ', ' .. ascii(e)
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end
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return '[' .. s .. ']'
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end
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function Set:insert(e) -- Add an element
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if not self.elem[e] then
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self.elem[e] = true
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self.n = self.n + 1
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end
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end
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function Set:erase(e) -- Remove an element
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if self.elem[e] then
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self.elem[e] = nil
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self.n = self.n - 1
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end
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end
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function Set:clear() -- Remove all elements
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self.elem = {}
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self.n = 0
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end
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function Set:size() -- Cardinality
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return self.n
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end
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function Set:contains(e) -- Check an element
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return self.elem[e] or false
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end
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function Set:clone() -- Clone
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local new = Set()
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new.n = self.n
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for e in pairs(self.elem) do new.elem[e] = true end
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return new
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end
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function Set:__add(r) -- Union
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local new = self:clone()
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for e in pairs(r.elem) do new:insert(e) end
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return new
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end
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function Set:__sub(r) -- Difference
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local new = Set()
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for e in pairs(self.elem) do if not r.elem[e] then new:insert(e) end end
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return new
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end
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function Set:__mod(r) -- Symmetric difference
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return (self - r) + (r - self)
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end
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function Set:__pow(r) -- Intersection
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local new = Set()
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for e in pairs(self.elem) do if r.elem[e] then new:insert(e) end end
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return new
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end
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function Set:__mul(r) -- Cartesian product
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local new = Set()
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for first in pairs(self.elem) do
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for second in pairs(r.elem) do
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new:insert(Tuple(first, second))
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end
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end
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return new
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end
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function Set:__le(r) -- Containment
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for e in pairs(self.elem) do if not r.elem[e] then return false end end
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return true
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end
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function Set:__lt(r) -- Strict containment
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return self <= r and self.n < r.n
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end
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function Set:__eq(r) -- Congruence
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return self <= r and self.n == r.n
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end
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