X-Git-Url: http://nitlanguage.org

diff --git a/lib/json/static.nit b/lib/json/static.nit
index fdb9f65..e333b85 100644
--- a/lib/json/static.nit
+++ b/lib/json/static.nit
@@ -31,6 +31,9 @@ private import json_lexer
 interface Jsonable
 	# Encode `self` in JSON.
 	#
+	# This is a recursive method which can be refined by any subclasses.
+	# To write any `Serializable` object to JSON, see `serialize_to_json`.
+	#
 	# SEE: `append_json`
 	fun to_json: String is abstract
 
@@ -47,9 +50,9 @@ interface Jsonable
 	# avoid cyclic references between `append_json` and `to_json` when none are
 	# implemented.
 	protected fun to_json_by_append: String do
-		var buffer = new RopeBuffer
+		var buffer = new FlatBuffer
 		append_json(buffer)
-		return buffer.write_to_string
+		return buffer.to_s
 	end
 
 	# Append the JSON representation of `self` to the specified buffer.
@@ -80,7 +83,7 @@ interface Jsonable
 		var res = new FlatBuffer
 		pretty_json_visit(res, 0)
 		res.add '\n'
-		return res.write_to_string
+		return res.to_s
 	end
 
 	private fun pretty_json_visit(buffer: FlatBuffer, indent: Int) is abstract
@@ -89,32 +92,40 @@ end
 redef class Text
 	super Jsonable
 
+	# Removes JSON-escaping if necessary in a JSON string
+	#
+	#     assert "\\\"string\\uD83D\\uDE02\\\"".unescape_json == "\"string😂\""
+	fun unescape_json: Text do
+		if not json_need_escape then return self
+		return self.json_to_nit_string
+	end
+
+	# Does `self` need treatment from JSON to Nit ?
+	#
+	# i.e. is there at least one `\` character in it ?
+	#
+	#     assert not "string".json_need_escape
+	#     assert "\\\"string\\\"".json_need_escape
+	protected fun json_need_escape: Bool do return has('\\')
+
 	redef fun append_json(buffer) do
 		buffer.add '\"'
-		for i in [0..self.length[ do
+		for i in [0 .. self.length[ do
 			var char = self[i]
 			if char == '\\' then
 				buffer.append "\\\\"
 			else if char == '\"' then
 				buffer.append "\\\""
-			else if char == '\/' then
-				buffer.append "\\/"
-			else if char < 16.ascii then
+			else if char < ' ' then
 				if char == '\n' then
 					buffer.append "\\n"
 				else if char == '\r' then
 					buffer.append "\\r"
 				else if char == '\t' then
 					buffer.append "\\t"
-				else if char == 0x0C.ascii then
-					buffer.append "\\f"
-				else if char == 0x08.ascii then
-					buffer.append "\\b"
 				else
-					buffer.append "\\u000{char.ascii.to_hex}"
+					buffer.append char.escape_to_utf16
 				end
-			else if char < ' ' then
-				buffer.append "\\u00{char.ascii.to_hex}"
 			else
 				buffer.add char
 			end
@@ -122,13 +133,65 @@ redef class Text
 		buffer.add '\"'
 	end
 
+	# Escapes `self` from a JSON string to a Nit string
+	#
+	#     assert "\\\"string\\\"".json_to_nit_string == "\"string\""
+	#     assert "\\nEscape\\t\\n".json_to_nit_string == "\nEscape\t\n"
+	#     assert "\\u0041zu\\uD800\\uDFD3".json_to_nit_string == "Azu𐏓"
+	protected fun json_to_nit_string: String do
+		var res = new FlatBuffer.with_capacity(bytelen)
+		var i = 0
+		var ln = self.length
+		while i < ln do
+			var char = self[i]
+			if char == '\\' then
+				i += 1
+				char = self[i]
+				if char == 'b' then
+					char = 0x08.code_point
+				else if char == 'f' then
+					char = 0x0C.code_point
+				else if char == 'n' then
+					char = '\n'
+				else if char == 'r' then
+					char = '\r'
+				else if char == 't' then
+					char = '\t'
+				else if char == 'u' then
+					var u16_esc = from_utf16_digit(i + 1)
+					char = u16_esc.code_point
+					if char.is_surrogate and i + 10 < ln then
+						if self[i + 5] == '\\' and self[i + 6] == 'u' then
+							u16_esc <<= 16
+							u16_esc += from_utf16_digit(i + 7)
+							char = u16_esc.from_utf16_surr.code_point
+							i += 6
+						else
+							char = 0xFFFD.code_point
+						end
+					end
+					i += 4
+				end
+				# `"`, `/` or `\` => Keep `char` as-is.
+			end
+			res.add char
+			i += 1
+		end
+		return res.to_s
+	end
+
+
 	# Encode `self` in JSON.
 	#
 	# ~~~
 	# assert "\t\"http://example.com\"\r\n\0\\".to_json ==
-	#     "\"\\t\\\"http:\\/\\/example.com\\\"\\r\\n\\u0000\\\\\""
+	#     "\"\\t\\\"http://example.com\\\"\\r\\n\\u0000\\\\\""
 	# ~~~
-	redef fun to_json do return to_json_by_append
+	redef fun to_json do
+		var b = new FlatBuffer.with_capacity(bytelen)
+		append_json(b)
+		return b.to_s
+	end
 
 	# Parse `self` as JSON.
 	#
@@ -175,6 +238,16 @@ redef class Text
 	end
 end
 
+redef class FlatText
+	redef fun json_need_escape do
+		var its = items
+		for i in [first_byte .. last_byte] do
+			if its[i] == 0x5Cu8 then return true
+		end
+		return false
+	end
+end
+
 redef class Buffer
 
 	# Append the JSON representation of `jsonable` to `self`.
@@ -369,6 +442,11 @@ redef class JsonParseError
 				"\"position\":{position.to_json}," +
 				"\"message\":{message.to_json}\}"
 	end
+
+	redef fun pretty_json_visit(buf, indents) do
+		buf.clear
+		buf.append(to_json)
+	end
 end
 
 redef class Position
@@ -426,41 +504,7 @@ end
 
 redef class Nstring
 	# The represented string.
-	private fun to_nit_string: String do
-		var res = new FlatBuffer
-		var i = 1
-		while i < text.length - 1 do
-			var char = text[i]
-			if char == '\\' then
-				i += 1
-				char = text[i]
-				if char == 'b' then
-					char = 0x08.ascii
-				else if char == 'f' then
-					char = 0x0C.ascii
-				else if char == 'n' then
-					char = '\n'
-				else if char == 'r' then
-					char = '\r'
-				else if char == 't' then
-					char = '\t'
-				else if char == 'u' then
-					var code = text.substring(i + 1, 4).to_hex
-					# TODO UTF-16 escaping is not supported yet.
-					if code >= 128 then
-						char = '?'
-					else
-						char = code.ascii
-					end
-					i += 4
-				end
-				# `"`, `/` or `\` => Keep `char` as-is.
-			end
-			res.add char
-			i += 1
-		end
-		return res.write_to_string
-	end
+	private fun to_nit_string: String do return text.substring(1, text.length - 2).unescape_json.to_s
 end
 
 redef class Nvalue_object