Arc Forum | Doesn't mzscheme already properly support: #hash((a . 1) (b . 2)) ?

Arc Forum

2 points by almkglor 5710 days ago | link | parent

Doesn't mzscheme already properly support:

   #hash((a . 1) (b . 2))

?

2 points by absz 5709 days ago | link

Yes, but Arc (or at least Anarki) does not:

  arc> #hash((a . 1) (b . 2))
  Error: "Type: unknown type #f"

We can, however, read it in, but this doesn't work either, since it creates immutable hash tables:

  arc> (= h (read "#hash((a . 1) (b . 2))"))
  #hash((b . 2) (a . 1))
  arc> h!b
  2
  arc> (= h!b 3)
  Error: "hash-table-put!: expects type <mutable hash-table> as 1st argument,
  given: #hash((b . 2) (a . 1)); other arguments were: b 3"

Fixing these would probably be worthwhile.

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1 point by stefano 5710 days ago | link

You're right! I didn't know it.

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