From e43dd849a122a59fa2c22278ddf9c9a09d1550bd Mon Sep 17 00:00:00 2001
From: Adam Chlipala <adam@chlipala.net>
Date: Sat, 19 Nov 2011 10:43:57 -0500
Subject: COALESCE

---
 src/monoize.sml | 22 ++++++++++++++++++++++
 src/urweb.grm   | 10 +++++++++-
 src/urweb.lex   |  1 +
 3 files changed, 32 insertions(+), 1 deletion(-)

(limited to 'src')

diff --git a/src/monoize.sml b/src/monoize.sml
index e570b4cb..d18b4d2a 100644
--- a/src/monoize.sml
+++ b/src/monoize.sml
@@ -2804,6 +2804,28 @@ fun monoExp (env, st, fm) (all as (e, loc)) =
                  fm)
             end
 
+          | (L.ECApp (
+             (L.ECApp (
+              (L.ECApp (
+               (L.ECApp (
+                (L.EFfi ("Basis", "sql_coalesce"), _), _),
+                _), _),
+               _), _),
+              _), _)) =>
+            let
+                val s = (L'.TFfi ("Basis", "string"), loc)
+                fun sc s = (L'.EPrim (Prim.String s), loc)
+            in
+                ((L'.EAbs ("x1", s, (L'.TFun (s, s), loc),
+                           (L'.EAbs ("x1", s, s,
+                                     strcat [sc "COALESCE(",
+                                             (L'.ERel 1, loc),
+                                             sc ",",
+                                             (L'.ERel 0, loc),
+                                             sc ")"]), loc)), loc),
+                 fm)
+            end
+
           | (L.ECApp (
              (L.ECApp (
               (L.ECApp (
diff --git a/src/urweb.grm b/src/urweb.grm
index db8b6294..8e3fad90 100644
--- a/src/urweb.grm
+++ b/src/urweb.grm
@@ -244,7 +244,7 @@ fun tnamesOf (e, _) =
  | TRUE | FALSE | CAND | OR | NOT
  | COUNT | AVG | SUM | MIN | MAX
  | ASC | DESC
- | INSERT | INTO | VALUES | UPDATE | SET | DELETE | NULL | IS
+ | INSERT | INTO | VALUES | UPDATE | SET | DELETE | NULL | IS | COALESCE
  | CURRENT_TIMESTAMP
  | NE | LT | LE | GT | GE
  | CCONSTRAINT | UNIQUE | CHECK | PRIMARY | FOREIGN | KEY | ON | NO | ACTION | RESTRICT | CASCADE | REFERENCES
@@ -1881,6 +1881,14 @@ sqlexp : TRUE                           (sql_inject (EVar (["Basis"], "True", In
                                          in
                                              (EApp (e, sqlexp), loc)
                                          end)
+       | COALESCE LPAREN sqlexp COMMA sqlexp RPAREN
+                                        (let
+                                             val loc = s (COALESCEright, sqlexp2right)
+                                             val e = (EVar (["Basis"], "sql_coalesce", Infer), loc)
+                                             val e = (EApp (e, sqlexp1), loc)
+                                         in
+                                             (EApp (e, sqlexp2), loc)
+                                         end)
        | fname LPAREN sqlexp RPAREN     (let
                                              val loc = s (fnameleft, RPARENright)
 
diff --git a/src/urweb.lex b/src/urweb.lex
index a989d933..8e8b0a12 100644
--- a/src/urweb.lex
+++ b/src/urweb.lex
@@ -499,6 +499,7 @@ xint = x[0-9a-fA-F][0-9a-fA-F];
 <INITIAL> "DELETE"    => (Tokens.DELETE (pos yypos, pos yypos + size yytext));
 <INITIAL> "NULL"      => (Tokens.NULL (pos yypos, pos yypos + size yytext));
 <INITIAL> "IS"        => (Tokens.IS (pos yypos, pos yypos + size yytext));
+<INITIAL> "COALESCE"  => (Tokens.COALESCE (pos yypos, pos yypos + size yytext));
 
 <INITIAL> "CONSTRAINT"=> (Tokens.CCONSTRAINT (pos yypos, pos yypos + size yytext));
 <INITIAL> "UNIQUE"    => (Tokens.UNIQUE (pos yypos, pos yypos + size yytext));
-- 
cgit v1.2.3