NAME

  Math::Expr::MatchSet - Represents matches in algebraic expretions

SYNOPSIS

  require Math::Expr::MatchSet;
  $s=new Math::Expr::MatchSet;
  $s->Set($pos,$match);
  $s->Get($pos);

DESCRIPTION

  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).

METHODS

$s=new Math::Expr::MatchSet

  Create a new MatchSet object.

$s->Set($pos, $match)

  Sets the match at $pos to $match.

$s->Add($pos, $match)

  Synonyme to Set.

$s->Insert($mset)

  Inserts all mathes in the MatchSet £mset intho $s.

$s->SetAll($var, $obj)

  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.

$s->tostr

  Generates a string representation of the MatchSet, used for debugging.

$s->Get($pos)

  Returns the Match at possition $pos.

$s->Keys

  Returns the positions at which there excists a match.