Hi,
I wrote a tiny patch to add support for array slicing:
>From 1be1435f8131934b7aae212c5d1ebb37ffe28f4a Mon Sep 17 00:00:00 2001
From: Nicolas Martyanoff <khae...@gmail.com>
Date: Mon, 25 Apr 2011 00:15:16 +0200
Subject: [PATCH] modify :[] to allow array slicing
---
doc/s-sql.html | 9 +++++----
s-sql/s-sql.lisp | 6 ++++--
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/doc/s-sql.html b/doc/s-sql.html
index 6ff1935..0fc185a 100644
--- a/doc/s-sql.html
+++ b/doc/s-sql.html
@@ -310,7 +310,7 @@
<p class="desc">Test whether a value is null.</p>
<p class="def"><span>sql-op</span> <a name="in"></a>:in (value set)</p>
-
+
<p class="desc">Test whether a value is in a set of values.</p>
<p class="def"><span>sql-op</span> <a name="not-in"></a>:not-in (value set)</p>
@@ -324,9 +324,10 @@
be given as multiple arguments to the operator. When they are not,
a single argument that evaulates to a list should be used.</p>
- <p class="def"><span>sql-op</span> <a name="deref"></a>:[] (form subscript)</p>
-
- <p class="desc">Dereference an array value.</p>
+ <p class="def"><span>sql-op</span> <a name="deref"></a>:[] (form start &optional end)</p>
+
+ <p class="desc">Dereference an array value. If <code>end</code> is
+ provided, extract a slice of the array.</p>
<p class="def"><span>sql-op</span> <a name="extract"></a>:extract (unit form)</p>
diff --git a/s-sql/s-sql.lisp b/s-sql/s-sql.lisp
index d299f88..66b1328 100644
--- a/s-sql/s-sql.lisp
+++ b/s-sql/s-sql.lisp
@@ -498,8 +498,10 @@ with a given arity."
:append `(" WHEN " ,@(sql-expand test) " THEN " ,@(sql-expand expr)))
" END"))
-(def-sql-op :[] (form subscript)
- `("(" ,@(sql-expand form) ")[" ,@(sql-expand subscript) "]"))
+(def-sql-op :[] (form start &optional end)
+ (if end
+ `("(" ,@(sql-expand form) ")[" ,@(sql-expand start) ":" ,@(sql-expand end) "]")
+ `("(" ,@(sql-expand form) ")[" ,@(sql-expand start) "]")))
;; This one has two interfaces. When the elements are known at
;; compile-time, they can be given as multiple arguments to the
--
1.7.4.4
So now:
(:[] #(1 2 4 8) 3) → "(ARRAY[1,2,4,8])[3]"
(:[] #(1 2 4 8) 2 4) → "(ARRAY[1,2,4,8])[2:4]"
I hope you will find it useful.
Best regards,
--
Nicolas Martyanoff
http://codemore.org
khae...@gmail.com
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