Struct NamedList 

pub struct NamedList {
    list: List,
    index: HashMap<String, usize>,
}

A named list with O(1) name-based element lookup.

Wraps a List and builds a HashMap<String, usize> index of element names on construction. Use this when you need to access multiple elements by name from the same list — each lookup is O(1) instead of O(n).

When to Use

Pattern	Type
Single named lookup	List::get_named is fine
Multiple named lookups	NamedList (O(n) build + O(1) per lookup)
Positional access only	List — no indexing overhead

Name Handling

• NA and empty-string names are excluded from the index
• If duplicate names exist, the last occurrence wins
• Positional access via get_index is always available

Fields

list: List

index: HashMap<String, usize>

Implementations

impl NamedList

pub fn as_data_frame(&self) -> Result<DataFrameView, DataFrameError>

Promote this named list to a DataFrameView.

Validates that all columns have equal length, then sets the class attribute to "data.frame" and adds compact integer row.names.

Errors

Returns DataFrameError::UnequalLengths if columns differ in length.

impl NamedList

pub fn new(list: List) -> Option<Self>

Build a NamedList from a List, indexing all non-empty, non-NA names.

Returns None if the list has no names attribute.

pub fn get<T>(&self, name: &str) -> Option<T>

where T: TryFromSexp<Error = SexpError>,

Get an element by name with O(1) lookup, converting to type T.

Returns None if the name is not found or conversion fails.

pub fn get_raw(&self, name: &str) -> Option<SEXP>

Get a raw SEXP element by name with O(1) lookup.

pub fn get_index<T>(&self, idx: isize) -> Option<T>

where T: TryFromSexp<Error = SexpError>,

Get element at 0-based index and convert to type T.

Falls through to List::get_index — no name lookup involved.

pub fn contains(&self, name: &str) -> bool

Check if a name exists in the index.

pub fn len(&self) -> isize

Number of elements in the list (including unnamed ones).

pub fn is_empty(&self) -> bool

Returns true if the list is empty.

pub fn named_len(&self) -> usize

Number of indexed (named) elements.

pub fn as_list(&self) -> List

Get the underlying List.

pub fn into_list(self) -> List

Consume and return the underlying List.

pub fn names(&self) -> impl Iterator<Item = &str>

Iterate over indexed names (unordered).

pub fn entries(&self) -> impl Iterator<Item = (&str, usize)>

Iterate over (name, position) pairs (unordered).

Trait Implementations

impl IntoR for NamedList

type Error = Infallible

The error type for fallible conversions.

fn try_into_sexp(self) -> Result<SEXP, Self::Error>

Try to convert this value to an R SEXP.

unsafe fn try_into_sexp_unchecked(self) -> Result<SEXP, Self::Error>

Try to convert to SEXP without thread safety checks.

fn into_sexp(self) -> SEXP

Convert this value to an R SEXP, panicking on error.

unsafe fn into_sexp_unchecked(self) -> SEXP

where Self: Sized,

Convert to SEXP without thread safety checks, panicking on error.

impl TryFromSexp for NamedList

type Error = SexpError

The error type returned when conversion fails.

fn try_from_sexp(sexp: SEXP) -> Result<Self, Self::Error>

Attempt to convert an R SEXP to this Rust type.

unsafe fn try_from_sexp_unchecked(sexp: SEXP) -> Result<Self, Self::Error>

Convert from SEXP without thread safety checks.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 56 bytes