Unicode «other number» characters not consistently accepted in identifiers

I’ve noticed that some characters classified as numeric by the Unicode standard will currently generate a lexical error. E.g., characters from the «enclosed alphanumerics» block don’t work, such as ① (circled digit one, U+2460), despite having being of the general Unicode category «other number». Usually, «other number» characters are accepted in identifiers. E.g., superscripts like «²» work fine.

This is related to #5108 , where modifier letters (which are also alphanumeric in Unicode) also throw a lexical error.

Trac metadata

Trac field	Value
Version	7.8.4
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (Parser)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed weight to 5

added Tbug Trac import parser labels

I can not reproduce your problem. U+2460 and U+00B2 are treated in the same way: allowed in variable identifiers, not allowed in operator identifiers. Just like numbers.

This compiles:

-- Superscript two (U+00B2)
-- Block: Latin-1 Supplement
-- General Category: OtherNumber (No)
-- Haskell: number
xB2 = '²'
xB2_² = 4
-- Error (numbers not allowed in operators):
-- data a +² b = XB2 a b


-- Circle digit 1 (U+2460)
-- Block: Enclosed Alphanumerics
-- General Category: OtherNumber (No)
-- Haskell: number
x2460 = '①'
x2460_① = 1
-- Error (numbers not allowed in operators):
--data a +① b = X2460 a b

Trac metadata

Trac field	Value
Related	→ #4373 (closed)

That is with GHC 7.8.4.

Please supply a small code snippet that you expect to work, but doesn't.

closed

zardoz: please reopen if you do think there is a bug in GHC.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedWorksForMe

added Pnormal label