Rename the xmpp-parsers directory to parsers

This doesn’t change anything to the name of the crate, just makes
autocompletion easier by not sharing the same prefix as the xmpp crate.

parsers/src/util/error.rs

@@ -0,0 +1,105 @@
+// Copyright (c) 2017-2018 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+use std::error::Error as StdError;
+use std::fmt;
+
+/// Contains one of the potential errors triggered while parsing an
+/// [Element](../struct.Element.html) into a specialised struct.
+#[derive(Debug)]
+pub enum Error {
+    /// The usual error when parsing something.
+    ///
+    /// TODO: use a structured error so the user can report it better, instead
+    /// of a freeform string.
+    ParseError(&'static str),
+
+    /// Generated when some base64 content fails to decode, usually due to
+    /// extra characters.
+    Base64Error(base64::DecodeError),
+
+    /// Generated when text which should be an integer fails to parse.
+    ParseIntError(std::num::ParseIntError),
+
+    /// Generated when text which should be a string fails to parse.
+    ParseStringError(std::string::ParseError),
+
+    /// Generated when text which should be an IP address (IPv4 or IPv6) fails
+    /// to parse.
+    ParseAddrError(std::net::AddrParseError),
+
+    /// Generated when text which should be a [JID](../../jid/struct.Jid.html)
+    /// fails to parse.
+    JidParseError(jid::JidParseError),
+
+    /// Generated when text which should be a
+    /// [DateTime](../date/struct.DateTime.html) fails to parse.
+    ChronoParseError(chrono::ParseError),
+}
+
+impl StdError for Error {
+    fn cause(&self) -> Option<&dyn StdError> {
+        match self {
+            Error::ParseError(_) => None,
+            Error::Base64Error(e) => Some(e),
+            Error::ParseIntError(e) => Some(e),
+            Error::ParseStringError(e) => Some(e),
+            Error::ParseAddrError(e) => Some(e),
+            Error::JidParseError(e) => Some(e),
+            Error::ChronoParseError(e) => Some(e),
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Error::ParseError(s) => write!(fmt, "parse error: {}", s),
+            Error::Base64Error(e) => write!(fmt, "base64 error: {}", e),
+            Error::ParseIntError(e) => write!(fmt, "integer parsing error: {}", e),
+            Error::ParseStringError(e) => write!(fmt, "string parsing error: {}", e),
+            Error::ParseAddrError(e) => write!(fmt, "IP address parsing error: {}", e),
+            Error::JidParseError(e) => write!(fmt, "JID parsing error: {}", e),
+            Error::ChronoParseError(e) => write!(fmt, "time parsing error: {}", e),
+        }
+    }
+}
+
+impl From<base64::DecodeError> for Error {
+    fn from(err: base64::DecodeError) -> Error {
+        Error::Base64Error(err)
+    }
+}
+
+impl From<std::num::ParseIntError> for Error {
+    fn from(err: std::num::ParseIntError) -> Error {
+        Error::ParseIntError(err)
+    }
+}
+
+impl From<std::string::ParseError> for Error {
+    fn from(err: std::string::ParseError) -> Error {
+        Error::ParseStringError(err)
+    }
+}
+
+impl From<std::net::AddrParseError> for Error {
+    fn from(err: std::net::AddrParseError) -> Error {
+        Error::ParseAddrError(err)
+    }
+}
+
+impl From<jid::JidParseError> for Error {
+    fn from(err: jid::JidParseError) -> Error {
+        Error::JidParseError(err)
+    }
+}
+
+impl From<chrono::ParseError> for Error {
+    fn from(err: chrono::ParseError) -> Error {
+        Error::ChronoParseError(err)
+    }
+}