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Math-Expr-LATEST
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/ Math::Expr::Opp

NAME

Math::Expr::Opp - Represents one operation in the 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 algebraic expressions. This class 
represents one operation or function with a set of operands, which 
in turn can be other Math::Expr::Opp objects. And in that way we are 
able to represent entire expression.

Operations like a+b and functions like sin(a) or f(a,b) are all 
represented by this kind of objects with "+", "sin" and "f" as the
operation- or function names and Math::Expr::Var(a) and 
Math::Expr::Var(b) as operands (only a in the sin example).

METHODS

$e=new Math::Expr::Opp($name,$db)

Creates a new operation object with the operation- or function-name 
$name. Using the operations defined in $db. See 
L<Math::Expr::OpperationDB> for more info.

$e->SetOpp($i, $v)

Sets operand number $i to $v.

$e->Opp($i)

Returns operand to number $i.

$e->tostr

Returns a string representation of the entire expression to be 
used for debugging.

$e->strtype

Returns a string representation of this expressions entire type, 
without simplifying it. In the same notation as the tostr method.

$n->Simplify

Simplifys the expression to some normal from.

$n->BaseType

Returns a string type of this expression simplifyed as much as 
possible.

$n->SubMatch($rules,$match)

Tries to match $rules to this expretions and adds the substitutions 
needed to $match.Returns 1 if the match excists and the substitutions 
needed can coexcist with those already in $match otherwise 0.

$n->Match($rules)

Tries to match $rules to this expretions and to all its subexpretions. 
Returns a MatchSet object specifying where the matches ocored and what 
substitutions they represent.

$n->Subs($vars)

Substitues all variables in the expretion with there vaules in $vars.

$n->Copy

Returns a copy of this object.

$n->Breakable

Used by the parser to indikate if this object was created using 
parantesis or if he should break it up to preserve the rules of order 
between the diffrent opperations.

$n->Find($pos)

Returns an object pointer to the subexpression represented by the 
string $pos.

$n->Set($pos, $val)

Replaces the subexpression at position $pos with $val.

AUTHOR

Hakan Ardo <hakan@debian.org>

SEE ALSO

L<Math::Expr>