Уже в нцатой книжке подряд вижу странное (для меня) оформление уточняющих вставок, без окружающих пробелов, аки дефис. «I didn’t care for the preaching-most kids didn’t-but there was more to Sunday church than worship». Всегда списывал это или на неточности верстки, или на огрехи OCR.
Посмотрел сейчас в сети — так они и правда не ставят пробелы. И таковы правила.
http://m.grammarbook.com/punctuation-rules/dashes.aspx
http://www.quickanddirtytips.com/education/grammar/em-dash-space
«Don’t put a space between an em-dash and the adjacent words»
Alex in Florida asked, “Should there be a space before and after a dash?”
Every style guide I checked, except the AP Stylebook, stated there should be no spaces between an em-dash and the adjacent words. That means it is a style choice. If you’re writing for a newspaper, magazine, or website that uses Associated Press style, put in the spaces. Otherwise, leave them out.
Being in America 