# HG changeset patch
# User Adam Chlipala <adam@chlipala.net>
# Date 1402510967 14400
# Node ID afeeabdcce77c359368453c4eb3b2eb629198c28
# Parent  6372a742ab040fa28a9099249a364129595c0807
let..where..end

diff -r 6372a742ab04 -r afeeabdcce77 doc/manual.tex
--- a/doc/manual.tex	Thu Jun 05 20:36:12 2014 +0000
+++ b/doc/manual.tex	Wed Jun 11 14:22:47 2014 -0400
@@ -625,6 +625,8 @@
 
 A signature item $\mt{table} \; x : c$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{sql\_table} \; c \; []$.  $\mt{view} \; x : c$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{sql\_view} \; c$, $\mt{sequence} \; x$ is short for $\mt{val} \; x : \mt{Basis}.\mt{sql\_sequence}$.  $\mt{cookie} \; x : \tau$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{http\_cookie} \; \tau$, and $\mt{style} \; x$ is shorthand for $\mt{val} \; x : \mt{Basis}.\mt{css\_class}$.
 
+It is possible to write a $\mt{let}$ expression with its constituents in reverse order, along the lines of Haskell's \cd{where}.  An expression $\mt{let} \; e \; \mt{where} \; ed^* \; \mt{end}$ desugars to $\mt{let} \; ed^* \; \mt{in} \; e \; \mt{end}$.
+
 
 \section{Static Semantics}
 
diff -r 6372a742ab04 -r afeeabdcce77 src/urweb.grm
--- a/src/urweb.grm	Thu Jun 05 20:36:12 2014 +0000
+++ b/src/urweb.grm	Wed Jun 11 14:22:47 2014 -0400
@@ -1456,6 +1456,7 @@
        | UNDER                          (EWild, s (UNDERleft, UNDERright))
 
        | LET edecls IN eexp END         (ELet (edecls, eexp), s (LETleft, ENDright))
+       | LET eexp WHERE edecls END      (ELet (edecls, eexp), s (LETleft, ENDright))
 
        | LBRACK RBRACK                  (EVar (["Basis"], "Nil", Infer), s (LBRACKleft, RBRACKright))
 
diff -r 6372a742ab04 -r afeeabdcce77 tests/letwhere.ur
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/letwhere.ur	Wed Jun 11 14:22:47 2014 -0400
@@ -0,0 +1,7 @@
+fun main () : transaction page =
+    let
+        return <xml>Hi {[alice]} and {[bob]}!</xml>
+    where
+        val alice = "Alice"
+        val bob = "Bob"
+    end