1ordsets(3)                 Erlang Module Definition                 ordsets(3)
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NAME

6       ordsets - Functions for manipulating sets as ordered lists.
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DESCRIPTION

10       Sets  are collections of elements with no duplicate elements. An ordset
11       is a representation of a set, where an ordered list is  used  to  store
12       the  elements of the set. An ordered list is more efficient than an un‐
13       ordered list. Elements are ordered according to the Erlang term order.
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15       This module provides the same interface as the sets(3) module but  with
16       a  defined  representation. One difference is that while sets considers
17       two elements as different if they do not match (=:=), this module  con‐
18       siders  two  elements  as  different if and only if they do not compare
19       equal (==).
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DATA TYPES

22       ordset(T) = [T]
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24              As returned by new/0.
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EXPORTS

27       add_element(Element, Ordset1) -> Ordset2
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29              Types:
30
31                 Element = E
32                 Ordset1 = ordset(T)
33                 Ordset2 = ordset(T | E)
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35              Returns a new ordered set formed from Ordset1 with  Element  in‐
36              serted.
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38       del_element(Element, Ordset1) -> Ordset2
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40              Types:
41
42                 Element = term()
43                 Ordset1 = Ordset2 = ordset(T)
44
45              Returns Ordset1, but with Element removed.
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47       filter(Pred, Ordset1) -> Ordset2
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49              Types:
50
51                 Pred = fun((Element :: T) -> boolean())
52                 Ordset1 = Ordset2 = ordset(T)
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54              Filters elements in Ordset1 with boolean function Pred.
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56       fold(Function, Acc0, Ordset) -> Acc1
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58              Types:
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60                 Function =
61                     fun((Element :: T, AccIn :: term()) -> AccOut :: term())
62                 Ordset = ordset(T)
63                 Acc0 = Acc1 = term()
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65              Folds  Function over every element in Ordset and returns the fi‐
66              nal value of the accumulator.
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68       from_list(List) -> Ordset
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70              Types:
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72                 List = [T]
73                 Ordset = ordset(T)
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75              Returns an ordered set of the elements in List.
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77       intersection(OrdsetList) -> Ordset
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79              Types:
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81                 OrdsetList = [ordset(term()), ...]
82                 Ordset = ordset(term())
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84              Returns the intersection of the non-empty list of sets.
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86       intersection(Ordset1, Ordset2) -> Ordset3
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88              Types:
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90                 Ordset1 = Ordset2 = Ordset3 = ordset(term())
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92              Returns the intersection of Ordset1 and Ordset2.
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94       is_disjoint(Ordset1, Ordset2) -> boolean()
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96              Types:
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98                 Ordset1 = Ordset2 = ordset(term())
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100              Returns true if Ordset1 and Ordset2 are disjoint (have  no  ele‐
101              ments in common), otherwise false.
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103       is_element(Element, Ordset) -> boolean()
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105              Types:
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107                 Element = term()
108                 Ordset = ordset(term())
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110              Returns  true  if  Element  is  an  element of Ordset, otherwise
111              false.
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113       is_empty(Ordset) -> boolean()
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115              Types:
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117                 Ordset = ordset(term())
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119              Returns true if Ordset is an empty set, otherwise false.
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121       is_set(Ordset) -> boolean()
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123              Types:
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125                 Ordset = term()
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127              Returns true if Ordset is an ordered set of elements,  otherwise
128              false.
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130       is_subset(Ordset1, Ordset2) -> boolean()
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132              Types:
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134                 Ordset1 = Ordset2 = ordset(term())
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136              Returns  true  when every element of Ordset1 is also a member of
137              Ordset2, otherwise false.
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139       new() -> []
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141              Returns a new empty ordered set.
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143       size(Ordset) -> integer() >= 0
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145              Types:
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147                 Ordset = ordset(term())
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149              Returns the number of elements in Ordset.
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151       subtract(Ordset1, Ordset2) -> Ordset3
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153              Types:
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155                 Ordset1 = Ordset2 = Ordset3 = ordset(term())
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157              Returns only the elements of Ordset1 that are not also  elements
158              of Ordset2.
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160       to_list(Ordset) -> List
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162              Types:
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164                 Ordset = ordset(T)
165                 List = [T]
166
167              Returns the elements of Ordset as a list.
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169       union(OrdsetList) -> Ordset
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171              Types:
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173                 OrdsetList = [ordset(T)]
174                 Ordset = ordset(T)
175
176              Returns the merged (union) set of the list of sets.
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178       union(Ordset1, Ordset2) -> Ordset3
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180              Types:
181
182                 Ordset1 = ordset(T1)
183                 Ordset2 = ordset(T2)
184                 Ordset3 = ordset(T1 | T2)
185
186              Returns the merged (union) set of Ordset1 and Ordset2.
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SEE ALSO

189       gb_sets(3), sets(3)
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193Ericsson AB                     stdlib 3.14.2.1                     ordsets(3)