Name Rascal/Libraries/Prelude/Relation/index

Synopsis Indexes a binary relation as a map

Function map[&K, set[&V]] index(rel[&K, &V] R)

Usage import Relation;

Description Converts a binary relation to a map of the domain to a set of the range.

Examples

rascal>import Relation;
ok
rascal>index({<1,10>, <2,20>, <3,30>, <30,10>});
map[int, set[int]]: (
  1:{10},
  2:{20},
  3:{30},
  30:{10}
)

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