Thomas,
let x = ... in ...
is only equal
do x - ...; ...
in the Identity monad. Also, why would do be more primitive than
let. That way you would have to use monads everywhere. Also,
let is treated specially by the type checker (IIRC) and there are
many, many other reasons not
Thomas, Stefan,
Thanks for a most edifying exchange! i will reflect on this.
Best wishes,
--greg
On 6/28/07, Stefan Holdermans [EMAIL PROTECTED] wrote:
Thomas,
let x = ... in ...
is only equal
do x - ...; ...
in the Identity monad. Also, why would do be more primitive than
Dave Bayer wrote:
[...] In the Haskell do expression, every line is equally special,
and type information is used to combine the lines, inserting implied
combinators.[...]
Desugaring do-notation is a syntactic transformation, requiring no type
information. (In practice, the parts may be
On Fri, 29 Jun 2007, Dave Bayer wrote:
One is immediately led back to the same idea as Haskell do expressions:
Two pieces of program, juxtaposed next to each other, silently
multiply to combine into a larger program, with type rules guiding the
multiplication process.
They don't,
On 29 jun 2007, at 16.26, Dave Bayer wrote:
That way you would have to use monads everywhere.
As you already hinted at in a later message, this has to do with
let-bindings being potentially polymorphic and monadic bindings
being necessarily monomorphic:
Are there papers that prove this
On Fri, Jun 29, 2007 at 07:26:21AM -0700, Dave Bayer wrote:
On Jun 28, 2007, at 9:49 PM, Stefan Holdermans wrote:
That way you would have to use monads everywhere.
As you already hinted at in a later message, this has to do with
let-bindings being potentially polymorphic and monadic
Haskellians,
Once you have a polymorphic let, why do you need 'let' in the base language,
at all? Is it possible to formulate Haskell entirely with do-notation where
there is a standard monad for let environments? Probably this was all
discussed before in the design deliberations for the
On 28 jun 2007, at 21.17, Greg Meredith wrote:
Once you have a polymorphic let, why do you need 'let' in the base
language, at all? Is it possible to formulate Haskell entirely with
do-notation where there is a standard monad for let environments?
Probably this was all discussed before
Thomas,
Thanks for the reply. My thinking was that once you have a polymorphic form,
why single out any other? Less moving parts makes for less maintenance, etc.
Best wishes,
--greg
On 6/28/07, Thomas Schilling [EMAIL PROTECTED] wrote:
On 28 jun 2007, at 21.17, Greg Meredith wrote:
Once
On Jun 28, 2007, at 12:17 PM, Greg Meredith wrote:
Haskellians,
Once you have a polymorphic let, why do you need 'let' in the base
language, at all? Is it possible to formulate Haskell entirely with
do-notation where there is a standard monad for let environments?
Probably this was all
On 28 jun 2007, at 22.02, Greg Meredith wrote:
Thomas,
Thanks for the reply. My thinking was that once you have a
polymorphic form, why single out any other? Less moving parts makes
for less maintenance, etc.
Ok, sorry if my reply seemed harsh. You are of course right, that
having
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