Verbosity Specifiers

Verbosity specifiers are the core mechanism for controlling which messages are emitted and at what level. They provide fine-grained control over different categories of output in your applications. These are not provided by the SciMLLogging package, but instead must be implemented by a package wishing to use the SciMLLogging interface.

Abstract Base Type

`AbstractVerbositySpecifier`

Creating Verbosity Specifiers

Package authors typically define their own verbosity specifier types by subtyping AbstractVerbositySpecifier. Each field in the struct represents a different category of messages that can be controlled independently.

Example Implementation

using SciMLLogging
using ConcreteStructs: @concrete

@concrete struct MyPackageVerbosity <: AbstractVerbositySpecifier
    initialization    # Controls startup and setup messages
    progress         # Controls progress and iteration updates
    convergence      # Controls convergence-related messages
    diagnostics      # Controls diagnostic messages
    performance      # Controls performance-related messages
end

Using the @concrete Macro

The @concrete macro from ConcreteStructs.jl is recommended for performance reasons:

• Type stability: Eliminates type instabilities that can hurt performance
• Compile-time optimization: Allows the compiler to generate more efficient code
• Zero-cost abstraction: Disabled verbosity ideally incurs no runtime

Configuring Message Categories

Each field in a verbosity specifier can be set to any AbstractMessageLevel:

# Create a custom configuration
custom_verbosity = MyPackageVerbosity(
    initialization = InfoLevel(),     # Show startup information
    progress = Silent(),             # Hide progress updates
    convergence = InfoLevel(),        # Show convergence status
    diagnostics = WarnLevel(),       # Show diagnostic messages
    performance = InfoLevel()        # Show performance info
)

Integration with Packages

Package authors should provide verbosity arguments in their main functions:

function solve_problem(problem; verbose = MyPackageVerbosity(Standard()), kwargs...)
    @SciMLMessage("Starting computation", verbose, :initialization)

    for i in 1:max_iterations
        @SciMLMessage("Iteration $i", verbose, :progress)

        # ... computation ...

        if converged
            @SciMLMessage("Converged after $i iterations", verbose, :convergence)
            break
        end
    end

    return result
end