Errors

Overview

gogenfilter uses branded errors with [gogenfilter:<code>] prefixes for structured error handling.

Pattern

filtered, err := f.ShouldFilter("nonexistent.go")
if err != nil {
    // Check for specific error types
    var ferr *gogenfilter.FilterError
    if errors.As(err, &ferr) {
        fmt.Println(ferr.Code())
    }
}

Error Interface

Errors implement:

• error — standard Go error interface
• ErrorCoder — returns a structured error code
• Helper — provides user-friendly error messages

Sentinel Errors

Use errors.Is for comparison:

errors.Is(err, gogenfilter.ErrFileNotFound)

Error Codes

Error codes use the pattern [gogenfilter:<code>] for easy grep and log filtering.

Generic Code Matching

Use CodeEqual[T] for type-safe error code comparison:

if gogenfilter.CodeEqual[gogenfilter.FileNotFoundCode](err) {
    // handle file not found
}