go-pathmatch/pattern_syntax_error.go

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package pathmatch
import (
"fmt"
)
// PatternSyntaxError is used to represent a specific kind of BadRequest error.
// Specifically, it represents a syntax error in the uncompiled pattern passed to the
// pathmatch.Compile() func.
//
// Example usage is as follows:
//
// pattern, err := pathmatch.Compile("/something/{there_is_a_syntax_error_in_this_pattern")
// if nil != err {
// switch err.(type) {
//
// case pathmatch.PatternSyntaxError: // ← Here we are detecting if the error returned was due to a syntax error, in the uncompiled pattern. Also note that it comes BEFORE the 'pathmatch.BadRequest' case; THAT IS IMPORTANT!
//
// fmt.Printf("The uncompiled pattern passed to pathmatch.Compile() had a syntax error in it. The error message describing the syntax error is....\n%s\n", err.Error())
// return
//
// case pathmatch.BadRequest:
//
// fmt.Printf("Something you did when you called pathmatch.Compile() caused an error. The error message was....\n%s\n", err.Error())
// return
//
// case pathmatch.InternalError:
//
// fmt.Printf("It's not your fault; it's our fault. Something bad happened internally when pathmatch.Compile() was running. The error message was....\n%s\n", err.Error())
// return
//
// default:
//
// fmt.Printf("Some kind of unexpected error happend: %v", err)
// return
// }
// }
type PatternSyntaxError interface {
BadRequest
PatternSyntaxError()
}
// internalPatternSyntaxError is the only underlying implementation that fits the
// PatternSyntaxError interface, in this library.
type internalPatternSyntaxError struct {
msg string
}
// newPatternSyntaxError creates a new internalPatternSyntaxError (struct) and
// returns it as a PatternSyntaxError (interface).
func newPatternSyntaxError(format string, a ...interface{}) PatternSyntaxError {
msg := fmt.Sprintf(format, a...)
err := internalPatternSyntaxError{
msg:msg,
}
return &err
}
// Error method is necessary to satisfy the 'error' interface (and the
// PatternSyntaxError interface).
func (err *internalPatternSyntaxError) Error() string {
s := fmt.Sprintf("Bad Request: Syntax Error: %s", err.msg)
return s
}
// BadRequest method is necessary to satisfy the 'InternalError' interface.
// It exists to make this error type detectable in a Go type-switch.
func (err *internalPatternSyntaxError) BadRequest() {
// Nothing here.
}
// PatternSyntaxError method is necessary to satisfy the 'PatternSyntaxError' interface.
// It exists to make this error type detectable in a Go type-switch.
func (err *internalPatternSyntaxError) PatternSyntaxError() {
// Nothing here.
}