Merge pull request #916 from matthiasbeyer/superceed-898

Simplify FoldResult implementation
This commit is contained in:
Matthias Beyer 2017-04-22 11:19:56 +02:00 committed by GitHub
commit 9396accc28
7 changed files with 49 additions and 28 deletions

View file

@ -46,7 +46,7 @@ impl<'a> Lister for LineLister<'a> {
use error::ListError as LE;
use error::ListErrorKind as LEK;
entries.fold_defresult(|entry| {
entries.fold_result(|entry| {
let s = entry.get_location().to_str().unwrap_or(String::from(self.unknown_output));
write!(stdout(), "{:?}\n", s).map_err(|e| LE::new(LEK::FormatError, Some(Box::new(e))))
})

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@ -47,7 +47,7 @@ impl Lister for PathLister {
use error::ListError as LE;
use error::ListErrorKind as LEK;
entries.fold_defresult(|entry| {
entries.fold_result(|entry| {
Ok(entry.get_location().clone())
.and_then(|pb| pb.into_pathbuf().map_err_into(LEK::FormatError))
.and_then(|pb| {

View file

@ -147,7 +147,7 @@ impl Configuration {
None => Err(CEK::ConfigOverrideKeyNotAvailable.into_error()),
}
})
.fold_defresult(|i| i)
.fold_result(|i| i)
.map_err(Box::new)
.map_err(|e| CEK::ConfigOverrideError.into_error_with_cause(e))
}
@ -274,4 +274,3 @@ fn fetch_config(rtp: &PathBuf) -> Result<Value> {
.map(|inner| Value::Table(inner.unwrap()))
.ok_or(ConfigErrorKind::NoConfigFileFound.into())
}

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@ -87,7 +87,7 @@ pub fn config_is_valid(config: &Option<Value>) -> Result<()> {
})
.and_then(|t| match *t {
Value::Array(ref a) => {
a.iter().fold_defresult(|elem| if is_match!(*elem, Value::String(_)) {
a.iter().fold_result(|elem| if is_match!(*elem, Value::String(_)) {
Ok(())
} else {
let cause = Box::new(kind.into_error());
@ -122,7 +122,7 @@ pub fn config_is_valid(config: &Option<Value>) -> Result<()> {
})
.and_then(|section_table| match *section_table { // which is
Value::Table(ref section_table) => // a table
section_table.iter().fold_defresult(|(inner_key, cfg)| {
section_table.iter().fold_result(|(inner_key, cfg)| {
match *cfg {
Value::Table(ref hook_config) => { // are tables
// with a key

View file

@ -73,7 +73,7 @@ impl StoreIdAccessor for Aspect {
return Err(HE::new(HEK::AccessTypeViolation, None));
}
accessors.iter().fold_defresult(|accessor| {
accessors.iter().fold_result(|accessor| {
let res = match accessor {
&HDA::StoreIdAccess(accessor) => accessor.access(id),
_ => unreachable!(),
@ -94,7 +94,7 @@ impl MutableHookDataAccessor for Aspect {
// More sophisticated version would check whether there are _chunks_ of
// NonMutableAccess accessors and execute these chunks in parallel. We do not have
// performance concerns yet, so this is okay.
accessors.iter().fold_defresult(|accessor| {
accessors.iter().fold_result(|accessor| {
let res = match accessor {
&HDA::StoreIdAccess(ref accessor) => accessor.access(fle.get_location()),
&HDA::NonMutableAccess(ref accessor) => accessor.access(fle),
@ -127,7 +127,7 @@ impl NonMutableHookDataAccessor for Aspect {
return Err(HE::new(HEK::AccessTypeViolation, None));
}
accessors.iter().fold_defresult(|accessor| {
accessors.iter().fold_result(|accessor| {
let res = match accessor {
&HDA::NonMutableAccess(accessor) => accessor.access(fle),
_ => unreachable!(),

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@ -1003,7 +1003,7 @@ impl Store {
match aspects.lock() {
Err(_) => return Err(HookErrorKind::HookExecutionError.into()),
Ok(g) => g
}.iter().fold_defresult(|aspect| {
}.iter().fold_result(|aspect| {
debug!("[Aspect][exec]: {:?}", aspect);
(aspect as &StoreIdAccessor).access(id)
}).map_err(Box::new)
@ -1025,7 +1025,7 @@ impl Store {
match aspects.lock() {
Err(_) => return Err(HookErrorKind::HookExecutionError.into()),
Ok(g) => g
}.iter().fold_defresult(|aspect| {
}.iter().fold_result(|aspect| {
debug!("[Aspect][exec]: {:?}", aspect);
aspect.access_mut(fle)
}).map_err(Box::new)
@ -2248,4 +2248,3 @@ aspect = "test"
assert!(store.update(&mut fle).is_ok());
}
}

View file

@ -1,4 +1,3 @@
//
// imag - the personal information management suite for the commandline
// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
//
@ -21,29 +20,53 @@
pub trait FoldResult: Sized {
type Item;
/// Processes all contained items returning the last successful result or the first error.
/// If there are no items, returns `Ok(R::default())`.
fn fold_defresult<R, E, F>(self, func: F) -> Result<R, E>
where R: Default,
F: FnMut(Self::Item)
-> Result<R, E>
{
self.fold_result(R::default(), func)
}
/// Processes all contained items returning the last successful result or the first error.
/// If there are no items, returns `Ok(default)`.
fn fold_result<R, E, F>(self, default: R, mut func: F) -> Result<R, E>
/// Apply a `FnMut(Self::Item) -> Result<R, E>` to each item. If each
/// application returns an `Ok(_)`, return `Ok(())`, indicating success.
/// Otherwise return the first error.
///
/// The return type of this function only indicates success with the
/// `Ok(())` idiom. To retrieve the values of your application, include an
/// accumulator in `func`. This is the intended reason for the permissive
/// `FnMut` type.
fn fold_result<R, E, F>(self, mut func: F) -> Result<(), E>
where F: FnMut(Self::Item) -> Result<R, E>;
}
impl<X, I: Iterator<Item = X>> FoldResult for I {
type Item = X;
fn fold_result<R, E, F>(self, default: R, mut func: F) -> Result<R, E>
fn fold_result<R, E, F>(self, mut func: F) -> Result<(), E>
where F: FnMut(Self::Item) -> Result<R, E>
{
self.fold(Ok(default), |acc, item| acc.and_then(|_| func(item)))
for item in self {
try!(func(item));
}
Ok(())
}
}
#[test]
fn test_fold_result_success() {
let v = vec![1, 2, 3];
let mut accum = vec![];
let result: Result<(), &str> = v.iter().fold_result(|item| {
accum.push(*item * 2);
Ok(*item)
});
assert_eq!(result, Ok(()));
assert_eq!(accum, vec![2, 4, 6]);
}
#[test]
fn test_fold_result_failure() {
let v: Vec<usize> = vec![1, 2, 3];
let mut accum: Vec<usize> = vec![];
let result: Result<(), &str> = v.iter().fold_result(|item| if *item == 2 {
Err("failure")
} else {
accum.push(*item * 2);
Ok(*item)
});
assert_eq!(result, Err("failure"));
assert_eq!(accum, vec![2]);
}