[Haskell-cafe] If you'd design a Haskell-like language, what would you do different?

[Hans Aberg]

On 21 Dec 2011, at 04:15, Brandon Allbery wrote:

> On Tue, Dec 20, 2011 at 21:05, Andrew Cowie <andrew at operationaldynamics.com> wrote:
>> Now we just need λ to replace \, → to replace ->, and ≠ to replace /=
>> (which still looks like division assignment no matter how hard I squint
>> my eyes. 25 years of C and C derived languages is hard to forget).
> Some of it is already supported.
> http://www.haskell.org/ghc/docs/latest/html/users_guide/syntax-extns.html#unicode-syntax
> 
> (≠ isn't in that list, but it doesn't need to be; just stick it in the Prelude if it's not there already, since it's not special syntax, it's just another operator.  The * *is* a special case, I suspect, though:  I bet it's only supported in kinds, not as the multiplication operator.)

The one on the list is not a mathematical symbol. It should be ⋆ STAR OPERATOR U+22C6 or ∗ ASTERISK OPERATOR U+2217.

> The problem with λ is that it's a perfectly valid Unicode lowercase letter.  There is 𝛌
> MATHEMATICAL BOLD SMALL LAMDA U+1D6CC but font support is often lacking, and it looks like Unicode categorizes *that* also as a lowercase letter.  If you can convince the Unicode Consortium to add a lambda that is of class symbol, Haskell can then make use of it — once there are fonts that support it.  

There is
  http://www.stixfonts.org/
For typesetting with Xe[La]TeX or Lua[La]TeX, use XITS (in the TeXLive package).

> (And then we'll have to deal with folks trying to use the letter, because everyone knows the Roman alphabet is the only one that matters and of *course* Greek letters are symbol characters....  Pfeh.)

This is the big problem right now: how to enter these symbols efficiently.

Hans