Name Rascal/Libraries/Prelude/Relation/domain

Synopsis Domain of a relation: a set consisting of the first element of each tuple.

Function

1. set[&T0] domain (rel[&T0,&T1] R)
2. set[&T0] domain (rel[&T0,&T1,&T2] R)
3. set[&T0] domain (rel[&T0,&T1,&T2,&T3] R)
4. set[&T0] domain (rel[&T0,&T1,&T2,&T3,&T4] R)

Usage import Relation;

Examples

rascal>import Relation;
ok
rascal>domain({<1,10>, <2,20>});
set[int]: {1,2}
rascal>domain({<"mon", 1>, <"tue", 2>});
set[str]: {"tue","mon"}

Questions

[Edit] | [New Subconcept] | [Recompile Course] | [Warnings]