Trait eccodes::FallibleIterator[−][src]

pub trait FallibleIterator {
    type Item;
    type Error;

Show 53 methods    fn next(&mut self) -> Result<Option<Self::Item>, Self::Error>;

    fn size_hint(&self) -> (usize, Option<usize>) { ... }

    fn count(self) -> Result<usize, Self::Error> { ... }

    fn last(self) -> Result<Option<Self::Item>, Self::Error> { ... }

    fn nth(&mut self, n: usize) -> Result<Option<Self::Item>, Self::Error> { ... }

    fn step_by(self, step: usize) -> StepBy<Self> { ... }

    fn chain<I>(self, it: I) -> Chain<Self, I>
    where
        I: IntoFallibleIterator<Item = Self::Item, Error = Self::Error>,
    { ... }

    fn zip<I>(
        self, 
        o: I
    ) -> Zip<Self, <I as IntoFallibleIterator>::IntoFallibleIter>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
    { ... }

    fn map<F, B>(self, f: F) -> Map<Self, F>
    where
        F: FnMut(Self::Item) -> Result<B, Self::Error>,
    { ... }

    fn for_each<F>(self, f: F) -> Result<(), Self::Error>
    where
        F: FnMut(Self::Item) -> Result<(), Self::Error>,
    { ... }

    fn filter<F>(self, f: F) -> Filter<Self, F>
    where
        F: FnMut(&Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn filter_map<B, F>(self, f: F) -> FilterMap<Self, F>
    where
        F: FnMut(Self::Item) -> Result<Option<B>, Self::Error>,
    { ... }

    fn enumerate(self) -> Enumerate<Self> { ... }

    fn peekable(self) -> Peekable<Self> { ... }

    fn skip_while<P>(self, predicate: P) -> SkipWhile<Self, P>
    where
        P: FnMut(&Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn take_while<P>(self, predicate: P) -> TakeWhile<Self, P>
    where
        P: FnMut(&Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn skip(self, n: usize) -> Skip<Self> { ... }

    fn take(self, n: usize) -> Take<Self> { ... }

    fn scan<St, B, F>(self, initial_state: St, f: F) -> Scan<Self, St, F>
    where
        F: FnMut(&mut St, Self::Item) -> Result<Option<B>, Self::Error>,
    { ... }

    fn flat_map<U, F>(self, f: F) -> FlatMap<Self, U, F>
    where
        U: IntoFallibleIterator<Error = Self::Error>,
        F: FnMut(Self::Item) -> Result<U, Self::Error>,
    { ... }

    fn flatten(self) -> Flatten<Self>
    where
        Self::Item: IntoFallibleIterator,
        <Self::Item as IntoFallibleIterator>::Error == Self::Error,
    { ... }

    fn fuse(self) -> Fuse<Self> { ... }

    fn inspect<F>(self, f: F) -> Inspect<Self, F>
    where
        F: FnMut(&Self::Item) -> Result<(), Self::Error>,
    { ... }

    fn by_ref(&mut self) -> &mut Self { ... }

    fn collect<T>(self) -> Result<T, Self::Error>
    where
        T: FromFallibleIterator<Self::Item>,
    { ... }

    fn partition<B, F>(self, f: F) -> Result<(B, B), Self::Error>
    where
        B: Default + Extend<Self::Item>,
        F: FnMut(&Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn fold<B, F>(self, init: B, f: F) -> Result<B, Self::Error>
    where
        F: FnMut(B, Self::Item) -> Result<B, Self::Error>,
    { ... }

    fn try_fold<B, E, F>(&mut self, init: B, f: F) -> Result<B, E>
    where
        E: From<Self::Error>,
        F: FnMut(B, Self::Item) -> Result<B, E>,
    { ... }

    fn all<F>(&mut self, f: F) -> Result<bool, Self::Error>
    where
        F: FnMut(Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn any<F>(&mut self, f: F) -> Result<bool, Self::Error>
    where
        F: FnMut(Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn find<F>(&mut self, f: F) -> Result<Option<Self::Item>, Self::Error>
    where
        F: FnMut(&Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn find_map<B, F>(&mut self, f: F) -> Result<Option<B>, Self::Error>
    where
        F: FnMut(Self::Item) -> Result<Option<B>, Self::Error>,
    { ... }

    fn position<F>(&mut self, f: F) -> Result<Option<usize>, Self::Error>
    where
        F: FnMut(Self::Item) -> Result<bool, Self::Error>,
    { ... }

    fn max(self) -> Result<Option<Self::Item>, Self::Error>
    where
        Self::Item: Ord,
    { ... }

    fn max_by_key<B, F>(self, f: F) -> Result<Option<Self::Item>, Self::Error>
    where
        B: Ord,
        F: FnMut(&Self::Item) -> Result<B, Self::Error>,
    { ... }

    fn max_by<F>(self, f: F) -> Result<Option<Self::Item>, Self::Error>
    where
        F: FnMut(&Self::Item, &Self::Item) -> Result<Ordering, Self::Error>,
    { ... }

    fn min(self) -> Result<Option<Self::Item>, Self::Error>
    where
        Self::Item: Ord,
    { ... }

    fn min_by_key<B, F>(self, f: F) -> Result<Option<Self::Item>, Self::Error>
    where
        B: Ord,
        F: FnMut(&Self::Item) -> Result<B, Self::Error>,
    { ... }

    fn min_by<F>(self, f: F) -> Result<Option<Self::Item>, Self::Error>
    where
        F: FnMut(&Self::Item, &Self::Item) -> Result<Ordering, Self::Error>,
    { ... }

    fn rev(self) -> Rev<Self>
    where
        Self: DoubleEndedFallibleIterator,
    { ... }

    fn unzip<A, B, FromA, FromB>(self) -> Result<(FromA, FromB), Self::Error>
    where
        Self: FallibleIterator<Item = (A, B)>,
        FromA: Default + Extend<A>,
        FromB: Default + Extend<B>,
    { ... }

    fn cloned<'a, T>(self) -> Cloned<Self>
    where
        Self: FallibleIterator<Item = &'a T>,
        T: 'a + Clone,
    { ... }

    fn cycle(self) -> Cycle<Self>
    where
        Self: Clone,
    { ... }

    fn cmp<I>(self, other: I) -> Result<Ordering, Self::Error>
    where
        I: IntoFallibleIterator<Item = Self::Item, Error = Self::Error>,
        Self::Item: Ord,
    { ... }

    fn partial_cmp<I>(self, other: I) -> Result<Option<Ordering>, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialOrd<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn eq<I>(self, other: I) -> Result<bool, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialEq<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn ne<I>(self, other: I) -> Result<bool, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialEq<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn lt<I>(self, other: I) -> Result<bool, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialOrd<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn le<I>(self, other: I) -> Result<bool, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialOrd<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn gt<I>(self, other: I) -> Result<bool, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialOrd<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn ge<I>(self, other: I) -> Result<bool, Self::Error>
    where
        I: IntoFallibleIterator<Error = Self::Error>,
        Self::Item: PartialOrd<<I as IntoFallibleIterator>::Item>,
    { ... }

    fn iterator(self) -> Iterator<Self> { ... }

    fn map_err<B, F>(self, f: F) -> MapErr<Self, F>
    where
        F: FnMut(Self::Error) -> B,
    { ... }

}
Expand description

An Iterator-like trait that allows for calculation of items to fail.

Associated Types

The type being iterated over.

The error type.

Required methods

Advances the iterator and returns the next value.

Returns Ok(None) when iteration is finished.

The behavior of calling this method after a previous call has returned Ok(None) or Err is implemenetation defined.

Provided methods

Returns bounds on the remaining length of the iterator.

Specifically, the first half of the returned tuple is a lower bound and the second half is an upper bound.

For the upper bound, None indicates that the upper bound is either unknown or larger than can be represented as a usize.

Both bounds assume that all remaining calls to next succeed. That is, next could return an Err in fewer calls than specified by the lower bound.

The default implementation returns (0, None), which is correct for any iterator.

Consumes the iterator, returning the number of remaining items.

Returns the last element of the iterator.

Returns the nth element of the iterator.

Returns an iterator starting at the same point, but stepping by the given amount at each iteration.

Panics

Panics if step is 0.

Returns an iterator which yields the elements of this iterator followed by another.

Returns an iterator that yields pairs of this iterator’s and another iterator’s values.

Returns an iterator which applies a fallible transform to the elements of the underlying iterator.

Calls a fallible closure on each element of an iterator.

Returns an iterator which uses a predicate to determine which values should be yielded. The predicate may fail; such failures are passed to the caller.

Returns an iterator which both filters and maps. The closure may fail; such failures are passed along to the consumer.

Returns an iterator which yields the current iteration count as well as the value.

Returns an iterator that can peek at the next element without consuming it.

Returns an iterator that skips elements based on a predicate.

Returns an iterator that yields elements based on a predicate.

Returns an iterator which skips the first n values of this iterator.

Returns an iterator that yields only the first n values of this iterator.

Returns an iterator which applies a stateful map to values of this iterator.

Returns an iterator which maps this iterator’s elements to iterators, yielding those iterators’ values.

Returns an iterator which flattens an iterator of iterators, yielding those iterators’ values.

Returns an iterator which yields this iterator’s elements and ends after the first Ok(None).

The behavior of calling next after it has previously returned Ok(None) is normally unspecified. The iterator returned by this method guarantees that Ok(None) will always be returned.

Returns an iterator which passes each element to a closure before returning it.

Borrow an iterator rather than consuming it.

This is useful to allow the use of iterator adaptors that would otherwise consume the value.

Transforms the iterator into a collection.

An Err will be returned if any invocation of next returns Err.

Transforms the iterator into two collections, partitioning elements by a closure.

Applies a function over the elements of the iterator, producing a single final value.

Applies a function over the elements of the iterator, producing a single final value.

This is used as the “base” of many methods on FallibleIterator.

Determines if all elements of this iterator match a predicate.

Determines if any element of this iterator matches a predicate.

Returns the first element of the iterator that matches a predicate.

Applies a function to the elements of the iterator, returning the first non-None result.

Returns the position of the first element of this iterator that matches a predicate. The predicate may fail; such failures are returned to the caller.

Returns the maximal element of the iterator.

Returns the element of the iterator which gives the maximum value from the function.

Returns the element that gives the maximum value with respect to the function.

Returns the minimal element of the iterator.

Returns the element of the iterator which gives the minimum value from the function.

Returns the element that gives the minimum value with respect to the function.

Returns an iterator that yields this iterator’s items in the opposite order.

Converts an iterator of pairs into a pair of containers.

Returns an iterator which clones all of its elements.

Returns an iterator which repeas this iterator endlessly.

Lexicographically compares the elements of this iterator to that of another.

Lexicographically compares the elements of this iterator to that of another.

Determines if the elements of this iterator are equal to those of another.

Determines if the elements of this iterator are not equal to those of another.

Determines if the elements of this iterator are lexicographically less than those of another.

Determines if the elements of this iterator are lexicographically less than or equal to those of another.

Determines if the elements of this iterator are lexicographically greater than those of another.

Determines if the elements of this iterator are lexicographically greater than or equal to those of another.

Returns a normal (non-fallible) iterator over Result<Item, Error>.

Returns an iterator which applies a transform to the errors of the underlying iterator.

Implementations on Foreign Types

Implementors

FallibleIterator implementation for CodesHandle to access GRIB messages inside file.

To access GRIB messages the ecCodes library uses a method similar to a C-style iterator. It digests the FILE * multiple times each time returning the codes_handle raw pointer to a message inside the file. This method would be unsafe to expose directly. Therefore this crate utilizes the Iterator to provide the access to GRIB messages in a safe and convienient way.

FallibleIterator is used instead of classic Iterator because internal ecCodes functions can return error codes when the GRIB file is corrupted and for some other reasons. The usage of FallibleIterator is sligthly different than usage of Iterator, check its documentation for more details.

For a true memory safety and to provide a ful Rust Iterator functionality, this iterator clones each message to a new buffer.Although internal ecCodes message copy implementation makes this operation quite cheap, using this iterator (and in effect this crate) comes with memory overhead, but is a necessity for memory safety.

Using the FallibleIterator is the only way to read KeyedMessages from the file. Its basic usage is simply with while let statement (similar to for loop for classic Iterator):

let file_path = Path::new("./data/iceland-surface.grib");
let product_kind = ProductKind::GRIB;

let mut handle = CodesHandle::new_from_file(file_path, product_kind).unwrap();

while let Some(message) = handle.next().unwrap() {
    let key = message.read_key("name").unwrap();

    if let KeyType::Str(name) = key.value {
        println!("{:?}", name);    
    }
}

The FallibleIterator can be collected to convert the handle into a Vector of KeyedMessages. For example:

let file_path = Path::new("./data/iceland-surface.grib");
let product_kind = ProductKind::GRIB;

let handle = CodesHandle::new_from_file(file_path, product_kind).unwrap();

let handle_collected: Vec<KeyedMessage> = handle.collect().unwrap();

Use of filter(), map() and other methods provided with Iterator allow for more advanced extracting of GRIB messages from the file.

Errors

The next() method will return CodesInternal when internal ecCodes function returns non-zero code.

FallibleIterator implementation for KeyedMessage to access keyes inside message. Mainly useful to discover what keys are present inside the message.

This function internally calls read_key() function so it is probably more efficient to call that function directly only for keys you are interested in.

FallibleIterator is used instead of classic Iterator because internal ecCodes functions can return internal error in some edge-cases. The usage of FallibleIterator is sligthly different than usage of Iterator, check its documentation for more details.

Example

let file_path = Path::new("./data/iceland.grib");
let product_kind = ProductKind::GRIB;

let mut handle = CodesHandle::new_from_file(file_path, product_kind).unwrap();
let mut current_message = handle.next().unwrap().unwrap();

while let Some(key) = current_message.next().unwrap() {
    println!("{:?}", key);
}

Errors

The next() method will return CodesInternal when internal ecCodes function returns non-zero code.