Add digraph {chars} to the list. {chars} must be a string with two characters. {digraph} is a string with one UTF-8 encoded character. Be careful, composing characters are NOT ignored. This function is similar to |:digraphs| command, but useful to add digraphs start with a white space. The function result is v:true if |digraph| is registered. If this fails an error message is given and v:false is returned. If you want to define multiple digraphs at once, you can use |digraph_setlist()|. Example: call digraph_set(' ', 'あ') Can be used as a |method|: GetString()->digraph_set('あ') This function works only when compiled with the |+digraphs| feature. If this feature is disabled, this function will display an error message.