Trainspotting The Musical, Theatre Royal Haymarket review - Irvine Welsh's junkie saga comes to the stage

If a week is a long time in politics, 30 years is an aeon in popular culture. It was in 1996 that Danny Boyle’s film of Irvine Welsh’s novel, Trainspotting, exploded over Britpop Britain, with its frequently horrifying but perversely life-affirming saga of a bunch of Edinburgh junkies.