[r2003-11-25 14:18:26 by cmiachon] comments about q6

Original author: cmiachon
Date: 2003-11-25 14:18:26+00:00

tests/cql/q6.cd

@@ -5,7 +5,11 @@ let fun count([Any*]->Int)
 
 (***************************)
 
-
+(*****************************************************************
+For each book that has at least one author, 
+list the title and first two authors, 
+and an empty "et-al" element if the book has additional authors.
+******************************************************************)
 let q6x=
 <bib>
 select 
@@ -23,3 +27,39 @@ select <book>[t  !a !(if etal=[] then [] else [<et-al>[]])]
 from <bib>[b::Book*] in [doc],
      <book>[t&Title ( a&Author | a::(Author Author) etal::_*) Publisher _*] in b;;
        
+
+
+(* le typage est differents entre q6x et q6p:
+on a pour q6x:
+ <bib {| |}>[ <book {| |}>[ X1 X2 | X1 X2 X2 | X1 X2 X2
+                                   <et-al {| |}>[  ] | X1 ]* ] where
+          X1 = <title>[ Char* ] and
+          X2 = <author>[ Last First ]
+et pour q6p:
+	  <bib {| |}>[ <book {| |}>[ Title Author | Title Author Author |
+                                   Title Author Author X1 | Title Author X1 ]* ] where
+          X1 = <et-al {| |}>[  ]
+
+Dans le premier cas on a soit 
++ Title Author               = Ok
++ Title Author Author        = Ok
++ Title Author Author Et-aL  = Ok
++ Title                      = pas possible d etre dans ce cas 
+                               avec la condition, mais le typage ne peut le
+			       detecter
+
+Dans le deuxieme cas on a soit:
++ Title Author	             =ok
++ Title Author Author        =ok
++ Title Author Author Et-aL  =ok
++ Title Author Et-al	     =ok pas possible aussi mais vient du if 
+
+
+il est rigolo de remarquer que pour cqlx on sait qu on aura pas de Title Author
+Et-al et qu en cqlp on sait qu on aura pas de Title tout court
+
+q6x n est pas entierement ecrit en cqlx puisqu on se sert de patterns
+patterns qu on pourrait utilise en cqlp et on aurait un type plus fin, mais une
+expression plus longue.
+
+*)