std.prototype 1.0.1

• Index

Contents

• Objects
• Initialisation
• Metamethods
• Module Functions

Modules

• std.prototype
• std.prototype.container
• std.prototype.object
• std.prototype.set
• std.prototype.strbuf
• std.prototype.trie

Module std.prototype.set

Set Prototype.

This module returns a table of set operators, as well as the prototype for a Set container object.

Every possible object or primitive value is always present in any Set container exactly zero or one times.

In addition to the functionality described here, Set containers also have all the methods and metamethods of the prototype.container.prototype (except where overridden here).

Prototype Chain

table
 `-> Container
      `-> Set

Objects

prototype

Set prototype object.

Initialisation

prototype._init

Set object initialisation.

Metamethods

prototype:__add (s)	Union operation.
prototype:__sub (s)	Difference operation.
prototype:__mul (s)	Intersection operation.
prototype:__div (s)	Symmetric difference operation.
prototype:__le (s)	Subset operation.
prototype:__lt (s)	Proper subset operation.
prototype:__tostring ()	Return a string representation of this set.

Module Functions

delete (set, e)	Delete an element from a set.
difference (set1, set2)	Find the difference of two sets.
elems (set)	Iterator for sets.
equal (set1, set2)	Find whether two sets are equal.
insert (set, e)	Insert an element into a set.
intersection (set1, set2)	Find the intersection of two sets.
difference (set, e)	Say whether an element is in a set.
proper_subset (set1, set2)	Find whether one set is a proper subset of another.
subset (set1, set2)	Find whether one set is a subset of another.
symmetric_difference (set1, set2)	Find the symmetric difference of two sets.
union (set1, set2)	Find the union of two sets.

Objects

prototype

Set prototype object.

Fields:

• _type string object name (default "Set")

See also:

prototype.container.prototype

Usage:

 local Set = require "std.prototype.set".prototype
 assert (prototype.type (Set) == "Set")

Initialisation

prototype._init

Set object initialisation.

Returns partially initialised Set container with contents from t.

Parameters:

• new table uninitialised Set container object
• t table initialisation table from __call

Metamethods

prototype:__add (s)

Union operation.

Parameters:

• s prototype another set

Returns:

prototype everything from this set plus everything from s

See also:

union

Usage:

union = this + s

prototype:__sub (s)

Difference operation.

Parameters:

• s prototype another set

Returns:

prototype everything from this set that is not also in s

See also:

difference

Usage:

difference = this - s

prototype:__mul (s)

Intersection operation.

Parameters:

• s prototype another set

Returns:

prototype anything in both this set and in s

See also:

intersection

Usage:

intersection = this * s

prototype:__div (s)

Symmetric difference operation.

Parameters:

• s prototype another set

Returns:

prototype everything in this set or in s but not in both

See also:

symmetric_difference

Usage:

symmetric_difference = this / s

prototype:__le (s)

Subset operation.

Parameters:

• s prototype another set

Returns:

boolean true if everything in this set is also in s

See also:

subset

Usage:

issubset = this <= s

prototype:__lt (s)

Proper subset operation.

Parameters:

• s prototype another set

Returns:

boolean true if s is not equal to this set, but does contain everything from this set

See also:

proper_subset

Usage:

ispropersubset = this < s

prototype:__tostring ()

Return a string representation of this set.

Returns:

string string representation of a set.

See also:

tostring

Module Functions

delete (set, e)

Delete an element from a set.

Parameters:

• set prototype a set
• e element

Returns:

prototype the modified set

Usage:

set.delete (available, found)

difference (set1, set2)

Find the difference of two sets.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

prototype a copy of set1 with elements of set2 removed

Usage:

all = set.difference (all, Set {32, 49, 56})

elems (set)

Iterator for sets.

Parameters:

• set prototype a set

Returns:

set iterator

Usage:

for code in set.elems (isprintable) do print (code) end

equal (set1, set2)

Find whether two sets are equal.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

boolean true if set1 and set2 each contain identical elements, false otherwise

Usage:

if set.equal (keys, Set {META, CTRL, "x"}) then process (keys) end

insert (set, e)

Insert an element into a set.

Parameters:

• set prototype a set
• e element

Returns:

prototype the modified set

Usage:

 for byte = 32,126 do
   set.insert (isprintable, string.char (byte))
 end

intersection (set1, set2)

Find the intersection of two sets.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

prototype a new set with elements in both set1 and set2

Usage:

common = set.intersection (a, b)

difference (set, e)

Say whether an element is in a set.

Parameters:

• set prototype a set
• e element

Returns:

true if e is in set, otherwise false otherwise

Usage:

if not set.member (keyset, pressed) then return nil end

proper_subset (set1, set2)

Find whether one set is a proper subset of another.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

boolean true if set2 contains all elements in set1 but not only those elements, false otherwise

Usage:

 if set.proper_subset (a, b) then
   for e in set.elems (set.difference (b, a)) do
     set.delete (b, e)
   end
 end
 assert (set.equal (a, b))

subset (set1, set2)

Find whether one set is a subset of another.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

boolean true if all elements in set1 are also in set2, false otherwise

Usage:

if set.subset (a, b) then a = b end

symmetric_difference (set1, set2)

Find the symmetric difference of two sets.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

prototype a new set with elements that are in set1 or set2 but not both

Usage:

unique = set.symmetric_difference (a, b)

union (set1, set2)

Find the union of two sets.

Parameters:

• set1 prototype a set
• set2 prototype another set

Returns:

prototype a copy of set1 with elements in set2 merged in

Usage:

all = set.union (a, b)