Hi,
I made some examples showing some apparent inconsistencies between the
documented SQL grammar and the implemented SQL grammar.
The 'rules' I talk about below refer to how the manual calls the non-terminals
in section 9.1.2 'Queries' of the Ur/Web manual.
type a = string
type b = string
table t : { A : a,
B : b}
con c = [A = a, B = b]
(* this is fine *)
val ok:transaction (option {T : {A : a, B : b}}) = oneOrNoRows (SELECT t.{{c}}
FROM t)
(* now, pick rule Q -> q -> P -> p,+ , this doesn't work. *)
val notok:transaction (option {T : {A : a, B : b}}) = oneOrNoRows (SELECT
t.{{c}}, FROM t)
(* let's take another derivation:
Q -> q -> P -> p -> E AS f
..... .....
.. ....
... ..
.. ...
t.{{c}} Whatever
=> t.{{c}} AS MyColumnName is a valid derivation
This is correct w.r.t. my reading of the grammar, but what does the compiler
tell us?
syntax error: replacing AS with COMMA
Parse failure
(Pay no attention to the wrong return type, since that is of no interest in this
example. )
*)
val not_ok2 : transaction (option {T : {A : a, B : b}}) = oneOrNoRows (SELECT
t.{{c}} AS Whatever FROM t)
--
Best regards,
Ron de Bruijn
_______________________________________________
Ur mailing list
[email protected]
http://www.impredicative.com/cgi-bin/mailman/listinfo/ur
