Enum IteratorKind 

pub enum IteratorKind {
    List {
        items: Vec<Value>,
        pos: usize,
    },
    Range {
        current: i64,
        end: i64,
        inclusive: bool,
        step: i64,
    },
    Set {
        items: Vec<Value>,
        pos: usize,
    },
    MapEntries {
        items: Vec<(Value, Value)>,
        pos: usize,
    },
    Map {
        source: Arc<Mutex<IteratorKind>>,
        func: FnValue,
    },
    Filter {
        source: Arc<Mutex<IteratorKind>>,
        pred: FnValue,
    },
    Take {
        source: Arc<Mutex<IteratorKind>>,
        remaining: usize,
    },
    Skip {
        source: Arc<Mutex<IteratorKind>>,
        to_skip: usize,
        skipped: bool,
    },
    Enumerate {
        source: Arc<Mutex<IteratorKind>>,
        index: usize,
    },
    Zip {
        a: Arc<Mutex<IteratorKind>>,
        b: Arc<Mutex<IteratorKind>>,
    },
    Chain {
        a: Arc<Mutex<IteratorKind>>,
        b: Arc<Mutex<IteratorKind>>,
        first_done: bool,
    },
}

The internal state of a lazy iterator.

Each variant wraps a source iterator (or raw data) and computes values on demand via IteratorKind::next. Combinators like map and filter require interpreter support to invoke Bock closures — these store the function value but their next() returns a special [IteratorNext::NeedsCallback] signal.

Variants

List

Iterate over a list of values.

Fields

items: Vec<Value>

pos: usize

Range

Iterate over an integer range.

Fields

current: i64

end: i64

inclusive: bool

step: i64

Set

Iterate over set elements.

Fields

items: Vec<Value>

pos: usize

MapEntries

Iterate over map entries as (key, value) tuples.

Fields

items: Vec<(Value, Value)>

pos: usize

Map

Lazy map combinator — requires interpreter callback.

Fields

source: Arc<Mutex<IteratorKind>>

func: FnValue

Filter

Lazy filter combinator — requires interpreter callback.

Fields

source: Arc<Mutex<IteratorKind>>

pred: FnValue

Take

Take at most N elements.

Fields

source: Arc<Mutex<IteratorKind>>

remaining: usize

Skip

Skip the first N elements.

Fields

source: Arc<Mutex<IteratorKind>>

to_skip: usize

skipped: bool

Enumerate

Attach an index to each element.

Fields

source: Arc<Mutex<IteratorKind>>

index: usize

Zip

Zip two iterators together.

Fields

a: Arc<Mutex<IteratorKind>>

b: Arc<Mutex<IteratorKind>>

Chain

Chain two iterators sequentially.

Fields

a: Arc<Mutex<IteratorKind>>

b: Arc<Mutex<IteratorKind>>

first_done: bool

Implementations

impl IteratorKind

pub fn next(&mut self) -> IteratorNext

Advance the iterator and return the next value.

For combinators that need Bock function calls (map, filter), this returns IteratorNext::NeedsMapCallback or IteratorNext::NeedsFilterCallback instead of a plain value.

Trait Implementations

impl Debug for IteratorKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.