A function which decides whether the row indicated by iter matches
a given key, and should be displayed as a possible completion for key.
Note that key is normalized and case-folded (see glib.global.utf8Normalize
and glib.global.utf8Casefold). If this is not appropriate, match functions
have access to the unmodified key via
gtk_editable_get_text (GTK_EDITABLE (gtk_entry_completion_get_entry ())).
A function which decides whether the row indicated by iter matches a given key, and should be displayed as a possible completion for key.
Note that key is normalized and case-folded (see glib.global.utf8Normalize and glib.global.utf8Casefold). If this is not appropriate, match functions have access to the unmodified key via gtk_editable_get_text (GTK_EDITABLE (gtk_entry_completion_get_entry ())).