NAME

  Math::Expr::Var - Represents one variable in a parsed expression tree

SYNOPSIS

  require Math::Expr::Opp;
  require Math::Expr::Var;
  require Math::Expr::Num;
  
  # To represent the expression "x+7":
  $n=new Math::Expr::Opp("+");
  $n->SetOpp(0,new Math::Expr::Var("x"));
  $n->SetOpp(1,new Math::Expr::Num(7));
  print $n->tostr . "\n";

DESCRIPTION

  Used by the Math::Expr to represent variables.

METHODS

$n=new Math::Expr::Var($name)

  Creates a new representation of the variable named $name.

$n->tostr

  Returns the string representation of the variable, that is the 
  variable name.

$n->strtype

  Returns the type of the variable.

$n->BaseType

  Simply cals strtype, its needed to be compatible with the other 
  elements in the structure.

$n->Simplify

  Needed to be compatible with the other elements in the structure. 
  Currently this does nothing, but we might have variable types in the 
  future that might need simplifications...

$n->Breakable

  Needed to be compatible with the other elements in the structure.

$n->Match

  Mathces a rule expression with the variable, and returns an array of 
  VarSet objects with this variable name set to the expression if there 
  types match.

$n->SubMatch

  Used by upper level Match procedure to match an entire expression.

$n->Subst($vars)

  Returns this variables vaule taken from $vars or a new copy of itselfe 
  if it does not excist.

$n->Copy

Returns a new copy of itself.

AUTHOR

  Hakan Ardo <hakan@debian.org>

SEE ALSO

  L<Math::Expr::Opp>