add `call' syntax to allow calling of arbitrary functions

ssql.scm

@@ -137,6 +137,15 @@
                ((insert (('into table) rest ...))
                 (self 'insert table rest))
 
+               ((call (function args ...))
+                (sprintf "~A(~A)"
+                         function
+                         (string-intersperse
+                          (map (lambda (arg) 
+                                 (self 'ssql->sql arg #t))
+                               args)
+                          ", ")))
+
                ((operator->sql type operator separator operands)
                 (case type
                   ((infix)

tests/ansi-test.scm

@@ -64,4 +64,8 @@
 (test-group "syntax"
   (test "set literals"
     "SELECT one, two FROM (1, 2)"
-    (ssql->sql #f '(select (columns one two) (from #(1 2))))))
+    (ssql->sql #f '(select (columns one two) (from #(1 2)))))
+
+  (test "function calls"
+    "SELECT foo(99, (bar('baz')))"
+    (ssql->sql #f '(select (call foo 99 (call bar "baz"))))))