Math::Expr::MatchSet - Represents matches in algebraic expretions
Two expretion can be matched in several ways, therefor we need to be
able to represent a set of matches keyed by the matchposition (the
subexpretion, where the match where found).
Create a new MatchSet object.
Sets the match at $pos to $match.
Synonyme to Set.
Inserts all mathes in the MatchSet £mset intho $s.
Sets the variable $var to $obj in all mathces in this set, and removes
all matches that already had a diffrent value for the variable $var.
Generates a string representation of the MatchSet, used for debugging.
Returns the Match at possition $pos.
Returns the positions at which there excists a match.