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changeset 231:eadeea528f75

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LIMIT
author Adam Chlipala <adamc@hcoop.net>
date Thu, 21 Aug 2008 16:00:01 -0400
parents 87d41ac28b30
children a338da9d82f3
files lib/basis.lig src/lacweb.grm src/lacweb.lex tests/limit.lac
diffstat 4 files changed, 29 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/lib/basis.lig	Thu Aug 21 15:50:08 2008 -0400
+++ b/lib/basis.lig	Thu Aug 21 16:00:01 2008 -0400
@@ -60,10 +60,15 @@
         -> sql_exp tables [] t -> sql_order_by tables
         -> sql_order_by tables
 
+type sql_limit
+val sql_no_limit : sql_limit
+val sql_limit : int -> sql_limit
+
 val sql_query : tables ::: {{Type}}
         -> selected ::: {{Type}}
         -> {Rows : sql_query1 tables selected,
-            OrderBy : sql_order_by tables}
+            OrderBy : sql_order_by tables,
+            Limit : sql_limit}
         -> sql_query selected
 
 val sql_field : otherTabs ::: {{Type}} -> otherFields ::: {Type} -> fieldType ::: Type -> agg ::: {{Type}}
--- a/src/lacweb.grm	Thu Aug 21 15:50:08 2008 -0400
+++ b/src/lacweb.grm	Thu Aug 21 16:00:01 2008 -0400
@@ -164,6 +164,7 @@
 
  | SELECT | FROM | AS | CWHERE | GROUP | ORDER | BY | HAVING
  | UNION | INTERSECT | EXCEPT
+ | LIMIT | OFFSET
  | TRUE | FALSE | CAND | OR | NOT
  | NE | LT | LE | GT | GE
 
@@ -245,6 +246,8 @@
  | hopt of exp
  | obopt of exp
  | obexps of exp
+ | lopt of exp
+ | sqlint of exp
 
 
 %verbose                                (* print summary of errors *)
@@ -658,13 +661,15 @@
        | STRING                         (EPrim (Prim.String STRING), s (STRINGleft, STRINGright))
        | LBRACE eexp RBRACE             (eexp)
 
-query  : query1 obopt                   (let
+query  : query1 obopt lopt              (let
                                              val loc = s (query1left, query1right)
 
                                              val re = (ERecord [((CName "Rows", loc),
                                                                  query1),
                                                                 ((CName "OrderBy", loc),
-                                                                 obopt)], loc)
+                                                                 obopt),
+                                                                ((CName "Limit", loc),
+                                                                 lopt)], loc)
                                          in
                                              (EApp ((EVar (["Basis"], "sql_query"), loc), re), loc)
                                          end)
@@ -844,3 +849,13 @@
                                          in
                                              (EApp (e, obexps), loc)
                                          end)
+
+lopt   :                                 (EVar (["Basis"], "sql_no_limit"), dummy)
+       | LIMIT sqlint                    (let
+                                              val loc = s (LIMITleft, sqlintright)
+                                          in
+                                              (EApp ((EVar (["Basis"], "sql_limit"), loc), sqlint), loc)
+                                          end)
+
+sqlint : INT                             (EPrim (Prim.Int INT), s (INTleft, INTright))
+       | LBRACE eexp RBRACE              (eexp)
--- a/src/lacweb.lex	Thu Aug 21 15:50:08 2008 -0400
+++ b/src/lacweb.lex	Thu Aug 21 16:00:01 2008 -0400
@@ -309,6 +309,8 @@
 <INITIAL> "ORDER"     => (Tokens.ORDER (pos yypos, pos yypos + size yytext));
 <INITIAL> "BY"        => (Tokens.BY (pos yypos, pos yypos + size yytext));
 <INITIAL> "HAVING"    => (Tokens.HAVING (pos yypos, pos yypos + size yytext));
+<INITIAL> "LIMIT"     => (Tokens.LIMIT (pos yypos, pos yypos + size yytext));
+<INITIAL> "OFFSET"    => (Tokens.OFFSET (pos yypos, pos yypos + size yytext));
 
 <INITIAL> "UNION"     => (Tokens.UNION (pos yypos, pos yypos + size yytext));
 <INITIAL> "INTERSECT" => (Tokens.INTERSECT (pos yypos, pos yypos + size yytext));
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/limit.lac	Thu Aug 21 16:00:01 2008 -0400
@@ -0,0 +1,4 @@
+table t : {A : int, B : string, C : float}
+
+val q1 = (SELECT * FROM t LIMIT 42)
+val q2 = fn n => (SELECT * FROM t LIMIT {n})