operations.md

Operations

Pipeline functions take an Enumerator[T] and return a new enumerator. Dispose the outermost enumerator when you own the chain (or use helpers like ForEach / ToSlice that dispose for you).

Transform

Function	Description
Map[T,U](enumerator, func(T) (U, error))	Project each element; mapper errors stop iteration
FlatMap	Map to inner enumerators and flatten
FilterMap	Map with optional skip

Filter

Function	Description
Filter	Keep elements matching predicate
Take	First n elements
Skip	Skip first n elements
TakeWhile	Prefix while predicate is true
SkipIf	Skip elements where predicate is true (not LINQ SkipWhile)
Distinct	Unique comparable elements

Combine

Function	Description
Chain[T](enumerators ...Enumerator[T])	Sequence enumerators back-to-back
Zip	Pair-wise combine two enumerators into Enumerator[Pair[T,U]]
Interleave	Merge ordered streams by priority

Group / chunk

Function	Description
Group	Group by key into Enumerator[Grouping[T,G]]
Chunk / ChunkByCount	Fixed-size sub-enumerators
Collect	Materialize Enumerator[Enumerator[T]] to [][]T

Terminal

Function	Description
ToSlice	([]T, error)
ForEach	Side effect per element
Any / All	Short-circuit predicates
Count	Element count
First / Last	(T, error) — ErrEmptySequence when empty
Min / Max	Ordered types
Sum	With selector

Context variants

MapWithContext, FilterWithContext pass context.Context into callbacks.

Notes

• Channel enumerators: call Complete() when publishing finishes
• Check Err() after loops; Current() can return per-element errors
• See package godoc and tests for full signatures