PowerBASIC

Adding uCalc to your PB application

In order to implement uCalc Fast Math Parser in PowerBASIC (PB/Win or PB/CC), follow these steps:

1. Copy uCalcPB.Bas to your project directory, or an appropriate include directory.
2. Place uCalc296.dll and ucFMP296.dll either in the Windows System directory, your project directory, or any suitable DLL directory that is in the path.
3. Place the following line towards the beginning of your source code:

#INCLUDE "uCalcPB.Bas"

Now you're all set to go.

Note: PowerBASIC files are found in the ucFMP296\PB\ directory.

Native callbacks

In other supported compilers, the Expr argument for native callbacks is passed as a Long or Dword integer. In PB, it is passed using the ucExpression type, which allows ucParam to be defined as a macro that deals directly with pointers. ucParam as a macro is faster than ucParam as a function.

Demo program

A user-friendly form-based demo is found in a file named DemoPB.Bas. The source code in that file demonstrates the essential features, especially as they relate to PowerBASIC. Because it is form-based, it will compile with PB/Win, and not PB/CC. However, if you only have PB/CC, you can still run the compiled DemoPB.exe file to see how it works.

Examples:

The following examples are for key features that may have some peculiarities in PowerBASIC. The following examples compile with PB/Win. In order to run them in PB/CC, change statements such as MsgBox to Print, and InputBox to Line Input. There are many more examples in Visual Basic that are close enough to PB. Those are listed under More Examples.

Example 1: Simple evaluation with ucEvalStr

Example 2: Fast evaluation millions of times in a loop

Example 3: Defining a centralized error handler

Example 4: Raising an error with ucRaiseErrorMessage

Example 5: A native function callback with two numeric arguments

Example 6: A native function callback with any number of arguments

Example 7: A native string callback function

Example 8: A non-native function callback

Example 9: Strings in non-native functions

Example 10: Attached variables

See More Examples

Remarks

• In the PowerBASIC help file, the phrase callback function is mainly associated with dialogs and controls. However, in uCalc, that phrase is not related to dialogs, controls, or Windows events. Under uCalc, a callback is a function in your source that is attached to a function definition in uCalc. It can also be an error handling routine that is invoked whenever an error is raised.
• In VB, ucReturn and ucReturnStr are Sub routines, whereas in PB, they are defined as macros, and require surrounding parenthesis, therefore:

ucReturn Expr, a + b ' This line will not compile

ucReturn(Expr, a + b) ' This line will compile

Also, ucReturnStr is a multi-line macro and should be the only statement in a line. Therefore the following line doesn't compile in PB/Win 8 or PB/CC 4:

If x = 1 Then ucReturnStr(Expr, "T") Else ucReturnStr(Expr, "F")

Do the following instead:

If x = 1 Then

ucReturnStr(Expr, "T")

Else

ucReturnStr(Expr, "F")

End If

• VB uses AddressOf MyFunc for the address of a function (where MyFunc is the function name), whereas PB uses CodePtr(MyFunc).
• The highest numeric type in the VB examples is Double. uCalc uses Extended by default, under PB.

New or enhanced in version 2.96

• ucEvaluate is imported differently in a way that makes it noticeably faster than before.
• ucReturn and ucParam are now implemented as macros instead of Sub routines for faster speed.

New or enhanced in version 2.9+

• A user-friendly form-based demo, just like VB's, was added.
• uCalc's syntax for PB is more uniform with that of other compilers.
• Initialization is done automatically. It is no longer necessary to call a function like ucEvaluateInit explicitly.