Group Type Testing

Returns the first non NIL/NULL expression among its arguments.

Coalesce( <Expression,...> ) --> <Expression>

Returns the first non empty expression among its arguments.

CoalesceEmpty( <Expression,...> ) --> <Expression>

Tests whether an expression returns an empty value.

Empty( <Expression> ) --> lEmpty

Tests if an expression evaluates to NULL/NIL.

IsNull( <Expression> ) --> lIsNull IsNull( <Expression>, <ReplacementValue> ) --> xValue

Determines the data type of an expression.

Type( <cExpression> ) --> cType

Determines the data type of a value.

Valtype( <Expression> ) --> cType