Struct Chain 

pub struct Chain {
    pub id: String,
    /* private fields */
}

Polymer chain containing an ordered list of residues.

The chain preserves the order residues were added, mirrors the chain identifier seen in structure files (e.g., "A"), and provides iteration helpers for both residues and atoms while keeping the internal storage private.

Fields

id: String

Chain identifier matching the source structure (usually a single character).

Implementations

impl Chain

pub fn new(id: &str) -> Self

Creates an empty chain with the provided identifier.

Use this constructor when building structures procedurally or when importing from file formats that enumerate chains.

Arguments

• id - Label matching the original structure’s chain identifier.

Returns

A new Chain with no residues.

pub fn add_residue(&mut self, residue: Residue)

Adds a residue to the chain while preventing duplicate identifiers.

Residues are appended in insertion order. Duplicate (id, insertion_code) pairs are rejected during debug builds to guard against malformed inputs.

Arguments

• residue - The residue to append.

pub fn residue(&self, id: i32, insertion_code: Option<char>) -> Option<&Residue>

Looks up a residue by identifier and optional insertion code.

Arguments

• id - Residue sequence number.
• insertion_code - Optional insertion code used in PDB/mmCIF records.

Returns

Some(&Residue) if a matching residue exists; otherwise None.

pub fn residue_mut( &mut self, id: i32, insertion_code: Option<char>, ) -> Option<&mut Residue>

Fetches a mutable reference to a residue by identifier.

Arguments

• id - Residue sequence number.
• insertion_code - Optional insertion code qualifier.

Returns

Some(&mut Residue) when present; otherwise None.

pub fn residues(&self) -> &[Residue]

Returns an immutable slice containing all residues in order.

Useful for bulk analysis or when interfacing with APIs that operate on slices.

Returns

Slice view of the underlying residue list.

pub fn residue_count(&self) -> usize

Reports the number of residues stored in the chain.

Returns

Count of residues currently tracked.

pub fn is_empty(&self) -> bool

Indicates whether the chain contains no residues.

Returns

true when the chain is empty.

pub fn iter_residues(&self) -> Iter<'_, Residue>

Provides an iterator over immutable residue references.

This mirrors residues() but avoids exposing slice internals and composes nicely with iterator adaptors.

Returns

A standard slice iterator over Residue references.

pub fn iter_residues_mut(&mut self) -> IterMut<'_, Residue>

Provides an iterator over mutable residue references.

Returns

A mutable slice iterator that allows in-place modifications.

pub fn iter_atoms(&self) -> impl Iterator<Item = &Atom>

Iterates over all atoms contained in the chain.

Residues are traversed in order and their atom iterators flattened, yielding atoms in the same relative ordering seen in the original structure.

Returns

Iterator that yields immutable Atom references.

pub fn iter_atoms_mut(&mut self) -> impl Iterator<Item = &mut Atom>

Iterates over all atoms with mutable access.

Returns

Iterator producing mutable Atom references for bulk editing operations.

pub fn retain_residues<F>(&mut self, f: F)

where F: FnMut(&Residue) -> bool,

Retains only residues that satisfy the provided predicate.

Arguments

• f - Predicate invoked for each residue; keep the residue when it returns true.

pub fn remove_residue( &mut self, id: i32, insertion_code: Option<char>, ) -> Option<Residue>

Removes a residue by identifier and returns ownership if found.

Arguments

• id - Residue number to remove.
• insertion_code - Optional insertion qualifier.

Returns

Some(Residue) containing the removed residue; otherwise None.

Trait Implementations

impl Clone for Chain

fn clone(&self) -> Chain

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Chain

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

Formats the value using the given formatter.

impl Display for Chain

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

Formats the value using the given formatter.

impl FromIterator<Chain> for Structure

fn from_iter<T: IntoIterator<Item = Chain>>(iter: T) -> Self

Creates a value from an iterator.

impl PartialEq for Chain

fn eq(&self, other: &Chain) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Chain