From 27931531a5ee30fc48224d1876e9574416d42289 Mon Sep 17 00:00:00 2001
From: Prashanth Mundkur <prashanth.mundkur@citrix.com>
Date: Fri, 8 May 2009 11:03:09 -0700
Subject: [PATCH] simplify json_conv error handling

---
 libs/json/json_conv.ml   | 22 ++++++++++++++++------
 libs/json/json_conv.mli  |  5 +++--
 libs/jsonrpc/jsonrpc.ml  |  8 ++++----
 libs/jsonrpc/jsonrpc.mli |  4 ++--
 4 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/libs/json/json_conv.ml b/libs/json/json_conv.ml
index 463c188..991d3d8 100644
--- a/libs/json/json_conv.ml
+++ b/libs/json/json_conv.ml
@@ -13,25 +13,35 @@
  * GNU Lesser General Public License for more details.
  *)
 
-type conv_error =
+type error =
 	| Unexpected_json_type of (* rcvd *) string * (* expected *) string
 	| Array_length of (* rcvd *) int * (* expected *) int
 	| Unknown_constructor of (* type *) string * (* constructor *) string
 	| Missing_object_field of string
 
-exception Json_conv_failure of conv_error
+let string_of_error = function
+	| Unexpected_json_type (r, e) ->
+		Printf.sprintf "type %s received when %s was expected" r e
+	| Array_length (r, e) ->
+		Printf.sprintf "array length %d received when %d was expected" r e
+	| Unknown_constructor (t, c) ->
+		Printf.sprintf "unknown constructor %s received for type %s" c t
+	| Missing_object_field f ->
+		Printf.sprintf "missing object field %s" f
+
+exception Json_conv_error of error
 
 let raise_unexpected_json_type typ exp =
-	raise (Json_conv_failure (Unexpected_json_type (typ, exp)))
+	raise (Json_conv_error (Unexpected_json_type (typ, exp)))
 
 let raise_short_array len exp =
-	raise (Json_conv_failure (Array_length (len, exp)))
+	raise (Json_conv_error (Array_length (len, exp)))
 
 let raise_unknown_constructor typ cons =
-	raise (Json_conv_failure (Unknown_constructor (typ, cons)))
+	raise (Json_conv_error (Unknown_constructor (typ, cons)))
 
 let raise_missing_object_field field =
-	raise (Json_conv_failure (Missing_object_field field))
+	raise (Json_conv_error (Missing_object_field field))
 
 let string_of_json ?(permissive=false) j =
 	let strict = function
diff --git a/libs/json/json_conv.mli b/libs/json/json_conv.mli
index 91dcf4b..921d221 100644
--- a/libs/json/json_conv.mli
+++ b/libs/json/json_conv.mli
@@ -15,13 +15,14 @@
 
 
 (* conversion errors *)
-type conv_error =
+type error =
 	| Unexpected_json_type of (* rcvd *) string * (* expected *) string
 	| Array_length of (* rcvd *) int * (* expected *) int
 	| Unknown_constructor of (* type *) string * (* constructor *) string
 	| Missing_object_field of string
+val string_of_error: error -> string
 
-exception Json_conv_failure of conv_error
+exception Json_conv_error of error
 
 
 (* conversion routines for base types *)
diff --git a/libs/jsonrpc/jsonrpc.ml b/libs/jsonrpc/jsonrpc.ml
index 284d540..db093d4 100644
--- a/libs/jsonrpc/jsonrpc.ml
+++ b/libs/jsonrpc/jsonrpc.ml
@@ -23,11 +23,11 @@ let code_error_invalid_params = -32602 	(* Invalid method parameters. *)
 let code_error_internal_error = -32603	(* Internal JSON-RPC error. *)
 
 type req_error =
-	| Request_json_conv_error of conv_error
+	| Request_json_conv_error of error
 	| Request_invalid_params
 
 type resp_error =
-	| Response_json_conv_error of conv_error
+	| Response_json_conv_error of error
 	| Response_no_result_or_error
 	| Response_both_result_and_error
 
@@ -63,7 +63,7 @@ let request_of_json j =
 		if not (Json.is_object params) && not (Json.is_array params) then
 			raise (Invalid_request Request_invalid_params);
 		{ request_id = id; method_name = method_name; params = params }
-	with Json_conv_failure e -> raise (Invalid_request (Request_json_conv_error e))
+	with Json_conv_error e -> raise (Invalid_request (Request_json_conv_error e))
 
 let request_of_string s = request_of_json (Json.of_string s)
 
@@ -105,7 +105,7 @@ let response_of_json j =
 			response_make_error id c m d
 		| _ ->
 			raise (Invalid_response Response_both_result_and_error)
-	with Json_conv_failure e -> raise (Invalid_response (Response_json_conv_error e))
+	with Json_conv_error e -> raise (Invalid_response (Response_json_conv_error e))
 
 let response_of_string s = response_of_json (Json.of_string s)
 
diff --git a/libs/jsonrpc/jsonrpc.mli b/libs/jsonrpc/jsonrpc.mli
index e343bce..bb54c14 100644
--- a/libs/jsonrpc/jsonrpc.mli
+++ b/libs/jsonrpc/jsonrpc.mli
@@ -20,11 +20,11 @@ val code_error_invalid_params : int
 val code_error_internal_error : int
 
 type req_error =
-	| Request_json_conv_error of Json_conv.conv_error
+	| Request_json_conv_error of Json_conv.error
 	| Request_invalid_params
 
 type resp_error =
-	| Response_json_conv_error of Json_conv.conv_error
+	| Response_json_conv_error of Json_conv.error
 	| Response_no_result_or_error
 	| Response_both_result_and_error
 
-- 
2.39.5