Struct HDict 

pub struct HDict { /* private fields */ }

Haystack Dict — the fundamental entity/row type in Haystack.

An HDict is a mutable dictionary mapping tag names (String) to values (Kind). Dicts are used as rows in grids, as entity records, and as metadata containers.

Implementations

impl HDict

pub fn new() -> Self

Create an empty dict.

pub fn from_tags(tags: HashMap<String, Kind>) -> Self

Create a dict from a pre-built HashMap.

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

Returns true if the dict contains a tag with the given name.

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

Returns a reference to the value for the given tag name, if present.

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

Returns true if the dict does NOT contain a tag with the given name.

pub fn id(&self) -> Option<&HRef>

Returns the id tag value if it is a Ref, otherwise None.

pub fn dis(&self) -> Option<&str>

Returns the display string for this dict.

Prefers the dis tag (if it is a Str), then falls back to the id ref’s display name.

pub fn is_empty(&self) -> bool

Returns true if the dict has no tags.

pub fn len(&self) -> usize

Returns the number of tags in the dict.

pub fn set(&mut self, name: impl Into<String>, val: Kind)

Set (insert or overwrite) a tag.

pub fn remove_tag(&mut self, name: &str) -> Option<Kind>

Remove a tag by name, returning its value if it was present.

pub fn merge(&mut self, other: &HDict)

Merge another dict into this one.

Tags from other overwrite tags in self. If a tag in other is Kind::Remove, the corresponding tag in self is removed instead.

pub fn tags(&self) -> &HashMap<String, Kind>

Returns a reference to the underlying HashMap.

pub fn iter(&self) -> impl Iterator<Item = (&str, &Kind)>

Iterate over (name, value) pairs.

pub fn sorted_iter(&self) -> Vec<(&str, &Kind)>

Iterate over tags sorted by key name.

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

Iterate over tag names.

pub fn tag_name_set(&self) -> HashSet<&str>

Collect all tag names into a HashSet.

Trait Implementations

impl Clone for HDict

fn clone(&self) -> HDict

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HDict

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

Formats the value using the given formatter.

impl Default for HDict

fn default() -> HDict

Returns the “default value” for a type.

impl Display for HDict

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

Formats the value using the given formatter.

impl PartialEq for HDict

fn eq(&self, other: &Self) -> 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.