ucParamHandle

See Also: ucDefineFunction, ucDefineOperator, ucParam, ucReturn

Returns the handle of an argument that was passed either ByHandle or ByExpr; for use with Native callback routines.

ucParamHandle(ExpressionHandle, ParamIndex)

Parameter

ExpressionHandle

All Native routines receive one argument, which is ExpressionHandle. This handle is required as the first argument of ucParamHandle().

ParamIndex

This represents the index of the argument you want.

Remarks

• Native callback routines (which are significantly faster than non-native callbacks) are intended for Standard License customers (though you can still test it, just like all other features, with the demo).
• ucParamHandle is merely a wrapper that looks like this in PowerBASIC:

Function ucParamHandle Alias "ucParamHandle" (ByVal Expr As ExpressionType Ptr, ByVal index As Long) Export As Dword

Function = @Expr.@ArgList[index].ValuePtr

End Function

Details for using pointers with native callback routines are beyond the scope of this help file.

Click on the following example links from the ucDefineFunction topic:

Example 1: Native callback ByExpr arguments

Example 2: Native callback ByHandle argument

New or enhanced in version 2.96

• ucParamHandle is an optimized replacement for ucParamExpr (which wasn't sufficiently documented before).