Ask HN: Why is #e#x+e#s+e-e#l-e a valid number in Racket?

2 points

9 years ago

Eli Barzley pointed out that Racket reads #e#x+e#s+e-e#l-e as a number.[1]

  $ racket
  Welcome to Racket v6.10.
  > #e#x+e#s+e@-e#l-e
  16140901064495857664-50176i

Why is it valid? According to https://docs.racket-lang.org/reference/reader.html, #s should be a structure literal.

I suppose this would be better as a StackOverflow question, but it's an interesting puzzle.

2 comments