/**
* In MathML, <plus/> and <times/> are n-ary operators but the infix
* FormulaParser represents them as binary operators. To ensure a
* consistent AST representation, this function is part of the n-ary to
* binary reduction process.
*/
static void
reduceBinary (ASTNode& node)
{
if (node.getNumChildren() == 2)
{
ASTNode* op = new ASTNode( node.getType() );
node.swapChildren(op);
node.prependChild(op);
}
}
/**
* Ensures the given ASTNode has the appropriate number of arguments. If
* arguments are missing, appropriate defaults (per the MathML 2.0
* specification) are added:
*
* log (x) -> log (10, x)
* root(x) -> root( 2, x)
*/
static void
checkFunctionArgs (ASTNode& node)
{
if (node.getNumChildren() == 1)
{
if (node.getType() == AST_FUNCTION_LOG)
{
ASTNode* child = new ASTNode;
child->setValue(10);
node.prependChild(child);
}
else if (node.getType() == AST_FUNCTION_ROOT)
{
ASTNode* child = new ASTNode;
child->setValue(2);
node.prependChild(child);
}
}
}