Collect
collect is an operation that consumes produced values and gathers them into a collection or other result.
Learn Rust in a Month of Lunches
collect is a Rust iterator method that gathers produced items into a collection or another type inferred or specified by the program.
- How it is used
- Consumes lazy iterator chains to turn their produced items into a new value.
- How deep it goes
- Works through Vec and HashMap examples, type specification, and an unused-iterator warning; does not detail collect’s implementation.
- Examples
- Uses doubled numbers collected into a Vec, zipped number-word pairs collected into a HashMap, and a compiler warning for unused map.
- What you can do after
- Apply it via Rust iterator chains to build a Vec or HashMap from mapped or zipped items.
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Kotlin in Action, 2E
collect is a Kotlin Flow terminal operation that suspends while collecting all emitted elements and optionally processes each element with a lambda.
- How it is used
- Executes a Flow and processes each emission, typically for side effects or incremental work.
- How deep it goes
- Explains suspension, cold-flow execution, lambda interleaving, repeated collection, and upstream exception boundaries.
- Examples
- Uses letters, timed emissions, temperature readings, repeated collection, onEach, and exception recovery with catch.
- What you can do after
- Apply it via Kotlin coroutines to process Flow emissions incrementally and perform suspending work for each value.
Idiomatic Rust
collect is an iterator method that consumes an iterator and builds a collection from its yielded items.
- How it is used
- Forces lazy iterator operations to run and gathers their yielded items into a collection.
- How deep it goes
- Explains type annotation, lazy evaluation, and collection examples, but does not detail collect’s implementation.
- Examples
- Demonstrates collecting mapped strings into a Vec and parsed values into a LinkedList.
- What you can do after
- Apply it via Rust iterators to evaluate transformations and build a chosen collection.
Related concepts
- vectorproduces · A vector is an ordered, indexed sequence of elements, often numerical, represented as a mathematical quantity or a computational collection.
- terminal operationkind of · A terminal operation ends a stream or sequence pipeline, triggers evaluation of preceding transformations, and produces a final result or side effect.
- try-catch statementused by · A try-catch statement is a control-flow construct that executes code under exception handling and transfers control to a matching handler when an exception is raised.
- upstream flowuses · An upstream flow is the portion of a flow, including preceding intermediate operators, that occurs before a specified operator.
- arrayproduces · An array is an indexed, ordered collection of elements arranged in one or more dimensions, with elements accessed by position.
- enumerateuses · enumerate is an iteration utility that yields pairs containing sequential indices and corresponding items from an iterable, optionally starting at a specified index.
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