[Bug] Compile time constants are raised as errors

[sancarn]

Small bug I imagine

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "stdLambda"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False

'Used for enabling some debugging features
#Const devMode = True 
'^^^^^^^^^^^^^^^^^^^ VBA Pro error on this line

also

[SSlinky]

You again! Good pick up. I'll get right on that :D

[SSlinky]

Not looking too bad. Something funky still going on with directives logic when used at sub level though, so I need to bug fix that before I push out a new version.

[sancarn]

Amazing! That looks fantastic! I wasn't expecting them to be functional in the slightest tbh 😅

[SSlinky]

I borrowed the same logic for the environment constants. I already had it replace things like VBA7 with true/false (based on user settings) so it wasn't much additional effort to have it evaluate the user defined constants to resolve a value, track that against the variable name, and then use that value to replace before evaluating the expression in the if block.

You're probably supposed^TM to use the AST to evaluate expressions but this is kind of a lazy hack :D

function transpileVbaToTypescript(exp: string, settings: DocumentSettings, directives: Map<string, any>): string {
	// Convert the environment constant to boolean.
	const envToBooleanText = (opt: string) => {
		const isOs = settings.environment.os.toLowerCase() == opt;
		const isVer = settings.environment.version.toLowerCase() == opt;
		return isOs || isVer ? 'true' : 'false';
	};

	// Set up text replacements map.
	const constants = ['vba6', 'vba7', 'mac', 'win16', 'win32', 'win64'];
	const replacements = new Map(constants.map(x => [x, envToBooleanText(x)]));
	replacements.set('or', '||');
	replacements.set('and', '&&');
	replacements.set('not ', '!');

	// Perform language text replacements.
	let result = exp;
	replacements.forEach((v, k) => {
		const regexp = RegExp(`${k}`, 'i');
		if (regexp.test(result)) {
			result = result.replace(regexp, v);
		}
	});

	// Perform user directives text replacements.
	directives.forEach((v, k) => {
		const regexp = RegExp(`${k}`, 'i');
		if (regexp.test(result)) {
			result = result.replace(regexp, v);
		}
	});

	return result;
}

[SSlinky]

Yeah, so we actually should eventually rewrite this to evaluate through the AST. If someone uses a constant expression that evaluates to a negative number, TS will coerce that to False where VBA will coerce it to True (anything not zero is true).

For example:

#Const TESTING = -1 * 5

Sub RunTest()
    #If TESTING Then
        Debug.Print "Secret message!"
    #End If
End Sub

The extension will fade that out as unreachable code but it's actually run by VBA.

[SSlinky]

I've fleshed out the different operators, bug fixed the grammar, and updated it so only the conditional block content is deactivated. Here's an example of it correctly evaluating UNTESTING to False which is then used to deactivate the block.

.

Similarly, we can invert again in the if expression.