plugin for sql

diff --git a/sql.ml b/sql.ml
new file mode 100644 (file)
index 0000000..080d07d
--- /dev/null
+++ b/sql.ml
@@ -0,0 +1,38 @@
+(* To be cleaned up - prototype version *)
+
+open Globals
+open Xpath_syntax
+open Printf
+
+type sql = Select of command_spec
+  | Insert of command_spec
+  | Update of command_spec
+  | Delete of command_spec
+and
+  command_spec = string list * string * expr option
+
+let rec str_of_expr = function
+  | String_literal(s)->sprintf "\"%s\"" s
+  | Number_literal(f)->if (f=1.0) then "true" else if (f=0.0) then "false" else sprintf "%f" f
+  | Var(s)->s
+  | Equal(e1,e2) -> (str_of_expr e1) ^ "=" ^ (str_of_expr e2)
+  | NotEqual(e1,e2) -> (str_of_expr e1) ^ "!=" ^ (str_of_expr e2)
+  | Lower(e1,e2) -> (str_of_expr e1) ^ "<" ^ (str_of_expr e2)
+  | Greater(e1,e2) -> (str_of_expr e1) ^ ">" ^ (str_of_expr e2)
+  | LowerEqual(e1,e2) -> (str_of_expr e1) ^ "<=" ^ (str_of_expr e2)
+  | GreaterEqual(e1,e2) -> (str_of_expr e1) ^ ">=" ^ (str_of_expr e2)
+  | _ -> print "Expression type not supported yet";raise AftError
+  | Or(e1,e2) -> (str_of_expr e1) ^ " or " ^ (str_of_expr e2)
+  | And(e1,e2) -> (str_of_expr e1) ^ " and " ^ (str_of_expr e2)
+  
+  
+let rec pretty_print_statement = function
+  | Select(colspec, tabspec, rowspec) -> 
+    let s_colspec = String.concat "," colspec in
+    let part1 = sprintf "Select %s from WHERE %s" s_colspec tabspec in
+    let part2 = match rowspec with
+      | None -> ""
+      | Some(expr) -> (str_of_expr(expr))
+    in
+      part1 ^ part2
+  | _ -> print "Statement type not supported yet";raise AftError