Throw information need to be more visual

rgb

Need to set "Throw" text information in bold, red color and with optional image warning

When you read doc, you can't perceive their importante information

bgrommes

rgb This points out a couple of holes in the language. IMO for every Parse() there should be a TryParse(). This allows efficient code like the following that avoids the overhead of setting up a Try/Catch block:

Var intValue As Integer = 0
If Integer.TryParse("Blah!",intValue) = False Then
  # Handle error condition, otherwise intValue (which is a ByRef argument) contains the parsed value
End If

I said "a couple" of holes: TryX() methods are arguably better implemented as an out parameter rather than ByRef but I suppose there's some unwritten Law Of Basic Dialects that says we can never go there ;-)

I suppose another path to handling this is to just hang a function argument off of ParseX() methods that can take an error handler which could be as simple as setting an "invalid value" flag for the item to be handled by subsequent code, etc.

rgb

I look also a method like:

Integer.Parse(text As String, optional DisableCatch as Boolean = false)

var x as integer = Integer.Parse("2", True)

#No catch if text are not good, return 0

bgrommes

rgb That could work, too -- or instead of a Boolean it could be a desired Integer default value such as Integer.MinValue, given that sometimes you need zero as a valid value. This idea also has the virtue of following the Objo vibe of simplicity. It's easier to grasp than "use the TryParse pattern" or "define a handler function for 100% flexibility in how to respond to unparsable data". It keeps the API surface smaller, too.

ETA: Come to think of it this would also be a nice addition to the helper functions in RecordSet. It could be used to define a default value for DB columns that are NULL. IIRC they currently default to zero. That is a bit problematic. It would also get around having to write extra boilerplate to check for null, etc.

The only weakness I can think of is Booleans. There are only two values for Booleans. That is where TryParse() would be better.

Garry

Good news guys TryParse is coming for Objo’s scalar types in the next release: https://feedback.objo.dev/feature/924

I've now implemented TryParse methods for:

Integer
Double
Currency
DateTime

Each type provides two forms:

TryParse(text, result)
TryParse(text, locale, result)

The result is passed by reference. The method returns True when parsing succeeds and stores the parsed value in the result variable:

Var value As Integer

If Integer.TryParse("42", value) Then
    Print(value) # 42
Else
    Print("That is not a valid integer.")
End If

If parsing fails, the method returns False and resets the result to the type’s default value: zero for numeric values and an empty value for DateTime.

Locale-aware parsing is also supported:

Var french As Locale = Locale.FromIdentifier("fr-FR")
Var value As Double

If Double.TryParse("1,5", french, value) Then
    Print(value) # 1.5
End If

I decided against adding a DisableCatch argument to Parse. Silently returning zero would make it impossible to distinguish invalid input from a legitimately parsed zero. TryParse keeps that distinction explicit without requiring a Try/Catch block.

The existing Parse methods have not changed: they still throw an InvalidArgumentException when parsing fails. In general:

Use Parse when invalid input represents an exceptional condition.
Use TryParse when invalid input is expected and needs validation, such as text entered by a user.

The compiler and VM were also updated so the Boolean result can be used directly inside another expression while still updating the referenced variable:

Var value As Integer
Print(Integer.TryParse("42", value))
Print(value)

Regarding making Throw information more visually prominent in the documentation has also been fixed in the next release of the docs.