Struct Frontmatter

pub struct Frontmatter(pub HashMap<String, Value>);

Represents the frontmatter, a collection of key-value pairs.

Tuple Fields

0: HashMap<String, Value>

Implementations

impl Frontmatter

pub fn new() -> Self

Creates a new, empty frontmatter.

Returns

A new Frontmatter instance with no key-value pairs.

Examples

use frontmatter_gen::Frontmatter;

let fm = Frontmatter::new();
assert!(fm.is_empty());

pub fn insert(&mut self, key: String, value: Value) -> Option<Value>

Inserts a key-value pair into the frontmatter.

Arguments

• key - The key for the entry.
• value - The value associated with the key.

Returns

An option containing the old value if it was replaced.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
assert_eq!(fm.insert("key".to_string(), Value::String("value".to_string())), None);
assert_eq!(fm.insert("key".to_string(), Value::Number(42.0)), Some(Value::String("value".to_string())));

pub fn get(&self, key: &str) -> Option<&Value>

Retrieves a reference to a value associated with a key.

Arguments

• key - The key to look up.

Returns

An option containing a reference to the value if the key exists.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("key".to_string(), Value::String("value".to_string()));
assert_eq!(fm.get("key"), Some(&Value::String("value".to_string())));
assert_eq!(fm.get("nonexistent"), None);

pub fn get_mut(&mut self, key: &str) -> Option<&mut Value>

Retrieves a mutable reference to a value associated with a key.

Arguments

• key - The key to look up.

Returns

An option containing a mutable reference to the value if the key exists.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("key".to_string(), Value::String("value".to_string()));
if let Some(value) = fm.get_mut("key") {
    *value = Value::Number(42.0);
}
assert_eq!(fm.get("key"), Some(&Value::Number(42.0)));

pub fn remove(&mut self, key: &str) -> Option<Value>

Removes a key-value pair from the frontmatter.

Arguments

• key - The key to remove.

Returns

An option containing the removed value if the key existed.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("key".to_string(), Value::String("value".to_string()));
assert_eq!(fm.remove("key"), Some(Value::String("value".to_string())));
assert_eq!(fm.remove("key"), None);

pub fn contains_key(&self, key: &str) -> bool

Checks if the frontmatter contains a given key.

Arguments

• key - The key to check for.

Returns

true if the key exists in the frontmatter, false otherwise.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("key".to_string(), Value::String("value".to_string()));
assert!(fm.contains_key("key"));
assert!(!fm.contains_key("nonexistent"));

pub fn len(&self) -> usize

Returns the number of entries in the frontmatter.

Returns

The number of key-value pairs in the frontmatter.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
assert_eq!(fm.len(), 0);
fm.insert("key".to_string(), Value::String("value".to_string()));
assert_eq!(fm.len(), 1);

pub fn is_empty(&self) -> bool

Checks if the frontmatter is empty.

Returns

true if the frontmatter contains no key-value pairs, false otherwise.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
assert!(fm.is_empty());
fm.insert("key".to_string(), Value::String("value".to_string()));
assert!(!fm.is_empty());

pub fn iter(&self) -> Iter<'_, String, Value>

Returns an iterator over the key-value pairs of the frontmatter.

Returns

An iterator over references to the key-value pairs.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("key1".to_string(), Value::String("value1".to_string()));
fm.insert("key2".to_string(), Value::Number(42.0));

for (key, value) in fm.iter() {
    println!("{}: {:?}", key, value);
}

pub fn iter_mut(&mut self) -> IterMut<'_, String, Value>

Returns a mutable iterator over the key-value pairs of the frontmatter.

Returns

A mutable iterator over references to the key-value pairs.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("key1".to_string(), Value::String("value1".to_string()));
fm.insert("key2".to_string(), Value::Number(42.0));

for (_, value) in fm.iter_mut() {
    if let Value::Number(n) = value {
        *n += 1.0;
    }
}

assert_eq!(fm.get("key2"), Some(&Value::Number(43.0)));

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

Merges another frontmatter into this one. If a key exists, it will be overwritten.

Arguments

• other - The frontmatter to merge into this one.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm1 = Frontmatter::new();
fm1.insert("key1".to_string(), Value::String("value1".to_string()));

let mut fm2 = Frontmatter::new();
fm2.insert("key2".to_string(), Value::Number(42.0));

fm1.merge(fm2);
assert_eq!(fm1.len(), 2);
assert_eq!(fm1.get("key2"), Some(&Value::Number(42.0)));

pub fn is_null(&self, key: &str) -> bool

Checks if a given key exists and its value is null.

Arguments

• key - The key to check.

Returns

true if the key exists and its value is null, false otherwise.

Examples

use frontmatter_gen::{Frontmatter, Value};

let mut fm = Frontmatter::new();
fm.insert("null_key".to_string(), Value::Null);
fm.insert("non_null_key".to_string(), Value::String("value".to_string()));

assert!(fm.is_null("null_key"));
assert!(!fm.is_null("non_null_key"));
assert!(!fm.is_null("nonexistent_key"));

pub fn clear(&mut self)

Clears the frontmatter while preserving allocated capacity

pub fn capacity(&self) -> usize

Returns the current capacity of the underlying HashMap

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements

Trait Implementations

impl Clone for Frontmatter

fn clone(&self) -> Frontmatter

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Frontmatter

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

Formats the value using the given formatter.

impl Default for Frontmatter

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Frontmatter

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Frontmatter

Implement Display for Frontmatter to allow easy printing with escaped characters.

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

Formats the value using the given formatter.

impl FromIterator<(String, Value)> for Frontmatter

Implement FromIterator for Frontmatter to create a frontmatter from an iterator.

fn from_iter<I: IntoIterator<Item = (String, Value)>>(iter: I) -> Self

Creates a Frontmatter from an iterator of key-value pairs.

Arguments

• iter - An iterator of key-value pairs where the key is a String and the value is a Value.

Returns

A Frontmatter containing the key-value pairs from the iterator.

Examples

use frontmatter_gen::{Frontmatter, Value};
use std::iter::FromIterator;

let pairs = vec![
    ("key1".to_string(), Value::String("value1".to_string())),
    ("key2".to_string(), Value::Number(42.0)),
];

let fm = Frontmatter::from_iter(pairs);
assert_eq!(fm.len(), 2);
assert_eq!(fm.get("key1"), Some(&Value::String("value1".to_string())));
assert_eq!(fm.get("key2"), Some(&Value::Number(42.0)));

impl IntoIterator for Frontmatter

Implement IntoIterator for Frontmatter to allow idiomatic iteration.

type Item = (String, Value)

The type of the elements being iterated over.

type IntoIter = IntoIter<String, Value>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl PartialEq for Frontmatter

fn eq(&self, other: &Frontmatter) -> 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 Serialize for Frontmatter

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Frontmatter