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use std::fmt::{self, Display};
use failure::{Context, Fail, Backtrace};
use ::MailType;
pub const UNKNOWN: &str = "<unknown>";
pub const UTF_8: &str = "utf-8";
pub const US_ASCII: &str = "us-ascii";
#[derive(Copy, Clone, Debug, Fail, PartialEq, Eq, Hash)]
pub enum EncodingErrorKind {
#[fail(display = "expected <{}> text encoding {} got ",
expected_encoding, got_encoding)]
InvalidTextEncoding {
expected_encoding: &'static str,
got_encoding: &'static str
},
#[fail(display = "hard line length limit breached (>= 998 bytes without CRLF)")]
HardLineLengthLimitBreached,
#[fail(display = "data can not be encoded with the {} encoding", encoding)]
NotEncodable {
encoding: &'static str,
},
#[fail(display = "malformed data")]
Malformed,
#[fail(display = "the mail body data cannot be accessed")]
AccessingMailBodyFailed,
#[fail(display = "{}", kind)]
Other { kind: &'static str }
}
#[derive(Debug)]
pub struct EncodingError {
inner: Context<EncodingErrorKind>,
mail_type: Option<MailType>,
str_context: Option<String>,
place: Option<Place>
}
#[derive(Debug)]
pub enum Place {
Header { name: &'static str },
Body
}
impl EncodingError {
pub fn kind(&self) -> EncodingErrorKind {
*self.inner.get_context()
}
pub fn mail_type(&self) -> Option<MailType> {
self.mail_type
}
pub fn str_context(&self) -> Option<&str> {
self.str_context.as_ref().map(|s| &**s)
}
pub fn set_str_context<I>(&mut self, ctx: I)
where I: Into<String>
{
self.str_context = Some(ctx.into());
}
pub fn with_str_context<I>(mut self, ctx: I) -> Self
where I: Into<String>
{
self.set_str_context(ctx);
self
}
pub fn with_place_or_else<F>(mut self, func: F) -> Self
where F: FnOnce() -> Option<Place>
{
if self.place.is_none() {
self.place = func();
}
self
}
pub fn with_mail_type_or_else<F>(mut self, func: F) -> Self
where F: FnOnce() -> Option<MailType>
{
if self.mail_type.is_none() {
self.mail_type = func();
}
self
}
}
impl From<EncodingErrorKind> for EncodingError {
fn from(ctx: EncodingErrorKind) -> Self {
EncodingError::from(Context::new(ctx))
}
}
impl From<Context<EncodingErrorKind>> for EncodingError {
fn from(inner: Context<EncodingErrorKind>) -> Self {
EncodingError {
inner,
mail_type: None,
str_context: None,
place: None
}
}
}
impl From<(EncodingErrorKind, MailType)> for EncodingError {
fn from((ctx, mail_type): (EncodingErrorKind, MailType)) -> Self {
EncodingError::from((Context::new(ctx), mail_type))
}
}
impl From<(Context<EncodingErrorKind>, MailType)> for EncodingError {
fn from((inner, mail_type): (Context<EncodingErrorKind>, MailType)) -> Self {
EncodingError {
inner,
mail_type: Some(mail_type),
str_context: None,
place: None
}
}
}
impl Fail for EncodingError {
fn cause(&self) -> Option<&Fail> {
self.inner.cause()
}
fn backtrace(&self) -> Option<&Backtrace> {
self.inner.backtrace()
}
}
impl Display for EncodingError {
fn fmt(&self, fter: &mut fmt::Formatter) -> fmt::Result {
if let Some(mail_type) = self.mail_type() {
write!(fter, "[{:?}]", mail_type)?;
} else {
write!(fter, "[<no_mail_type>]")?;
}
Display::fmt(&self.inner, fter)
}
}
#[macro_export]
macro_rules! ec_bail {
(kind: $($tt:tt)*) => ({
return Err($crate::error::EncodingError::from(
$crate::error::EncodingErrorKind:: $($tt)*).into())
});
(mail_type: $mt:expr, kind: $($tt:tt)*) => ({
return Err($crate::error::EncodingError::from((
$crate::error::EncodingErrorKind:: $($tt)*,
$mt
)).into())
});
}
#[cfg(test)]
mod test {
#[test]
fn bail_compiles_v1() {
let func = || -> Result<(), ::error::EncodingError> {
ec_bail!(kind: Other { kind: "test"});
#[allow(unreachable_code)] Ok(())
};
assert!((func)().is_err());
}
#[test]
fn bail_compiles_v2() {
fn mail_type() -> ::MailType { ::MailType::Internationalized }
let func = || -> Result<(), ::error::EncodingError> {
ec_bail!(mail_type: mail_type(), kind: Other { kind: "testicle" });
#[allow(unreachable_code)] Ok(())
};
assert!((func)().is_err());
}
}