Enum Value 

pub enum Value {
    Null,
    String(String),
    Number(f64),
    Boolean(bool),
    Array(Vec<Value>),
    Object(Box<Frontmatter>),
    Tagged(String, Box<Value>),
}

A flexible value type that can hold various types of data found in frontmatter.

Variants

Null

Represents a null value.

String(String)

Represents a string value.

Number(f64)

Represents a numeric value.

Boolean(bool)

Represents a boolean value.

Array(Vec<Value>)

Represents an array of values.

Object(Box<Frontmatter>)

Represents an object (frontmatter).

Tagged(String, Box<Value>)

Represents a tagged value, containing a tag and a value.

Implementations

impl Value

Accessor and conversion methods for Value.

These methods provide ergonomic type-checked projections (as_str, as_float, as_bool, as_array, as_object, as_tagged), along with emptiness checks, recursive deep merges for nested Frontmatter objects, and formatting utilities across YAML, TOML, and JSON values.

See the individual method documentation for examples.

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

Returns the value as a string slice, if it is of type String.

Returns

• Some(&str) if the value is a String.
• None if the value is not a String.

Examples

use frontmatter_gen::Value;

let string_value = Value::String("Hello".to_string());
assert_eq!(string_value.as_str(), Some("Hello"));

let number_value = Value::Number(42.0);
assert_eq!(number_value.as_str(), None);

pub const fn as_f64(&self) -> Option<f64>

Returns the value as a float, if it is of type Number.

Returns

• Some(f64) if the value is a Number.
• None if the value is not a Number.

Examples

use frontmatter_gen::Value;

let number_value = Value::Number(3.14);
assert_eq!(number_value.as_f64(), Some(3.14));

let string_value = Value::String("Not a number".to_string());
assert_eq!(string_value.as_f64(), None);

pub const fn as_bool(&self) -> Option<bool>

Returns the value as a boolean, if it is of type Boolean.

Returns

• Some(bool) if the value is a Boolean.
• None if the value is not a Boolean.

Examples

use frontmatter_gen::Value;

let bool_value = Value::Boolean(true);
assert_eq!(bool_value.as_bool(), Some(true));

let string_value = Value::String("Not a boolean".to_string());
assert_eq!(string_value.as_bool(), None);

pub const fn as_array(&self) -> Option<&Vec<Value>>

Returns the value as an array, if it is of type Array.

Returns

• Some(&Vec<Value>) if the value is an Array.
• None if the value is not an Array.

Examples

use frontmatter_gen::Value;

let array_value = Value::Array(vec![Value::Number(1.0), Value::Number(2.0)]);
assert!(array_value.as_array().is_some());
assert_eq!(array_value.as_array().unwrap().len(), 2);

let string_value = Value::String("Not an array".to_string());
assert!(string_value.as_array().is_none());

pub fn as_object(&self) -> Option<&Frontmatter>

Returns the value as an object (frontmatter), if it is of type Object.

Returns

• Some(&Frontmatter) if the value is an Object.
• None if the value is not an Object.

Examples

use frontmatter_gen::{Value, Frontmatter};

let mut fm = Frontmatter::new();
fm.insert("key".to_string(), Value::String("value".to_string()));
let object_value = Value::Object(Box::new(fm));
assert!(object_value.as_object().is_some());

let string_value = Value::String("Not an object".to_string());
assert!(string_value.as_object().is_none());

pub fn as_tagged(&self) -> Option<(&str, &Value)>

Returns the value as a tagged value, if it is of type Tagged.

Returns

• Some((&str, &Value)) if the value is Tagged.
• None if the value is not Tagged.

Examples

use frontmatter_gen::Value;

let tagged_value = Value::Tagged("tag".to_string(), Box::new(Value::Number(42.0)));
assert_eq!(tagged_value.as_tagged(), Some(("tag", &Value::Number(42.0))));

let string_value = Value::String("Not tagged".to_string());
assert_eq!(string_value.as_tagged(), None);

pub const fn is_null(&self) -> bool

Checks if the value is of type Null.

Returns

true if the value is Null, otherwise false.

Examples

use frontmatter_gen::Value;

let null_value = Value::Null;
assert!(null_value.is_null());

let string_value = Value::String("Not null".to_string());
assert!(!string_value.is_null());

pub const fn is_string(&self) -> bool

Checks if the value is of type String.

Returns

true if the value is a String, otherwise false.

Examples

use frontmatter_gen::Value;

let string_value = Value::String("Hello".to_string());
assert!(string_value.is_string());

let number_value = Value::Number(42.0);
assert!(!number_value.is_string());

pub const fn is_number(&self) -> bool

Checks if the value is of type Number.

Returns

true if the value is a Number, otherwise false.

Examples

use frontmatter_gen::Value;

let number_value = Value::Number(3.14);
assert!(number_value.is_number());

let string_value = Value::String("Not a number".to_string());
assert!(!string_value.is_number());

pub const fn is_boolean(&self) -> bool

Checks if the value is of type Boolean.

Returns

true if the value is a Boolean, otherwise false.

Examples

use frontmatter_gen::Value;

let bool_value = Value::Boolean(true);
assert!(bool_value.is_boolean());

let string_value = Value::String("Not a boolean".to_string());
assert!(!string_value.is_boolean());

pub const fn is_array(&self) -> bool

Checks if the value is of type Array.

Returns

true if the value is an Array, otherwise false.

Examples

use frontmatter_gen::Value;

let array_value = Value::Array(vec![Value::Number(1.0), Value::Number(2.0)]);
assert!(array_value.is_array());

let string_value = Value::String("Not an array".to_string());
assert!(!string_value.is_array());

pub const fn is_object(&self) -> bool

Checks if the value is of type Object.

Returns

true if the value is an Object, otherwise false.

Examples

use frontmatter_gen::{Value, Frontmatter};

let object_value = Value::Object(Box::new(Frontmatter::new()));
assert!(object_value.is_object());

let string_value = Value::String("Not an object".to_string());
assert!(!string_value.is_object());

pub const fn is_tagged(&self) -> bool

Checks if the value is of type Tagged.

Returns

true if the value is Tagged, otherwise false.

Examples

use frontmatter_gen::Value;

let tagged_value = Value::Tagged("tag".to_string(), Box::new(Value::Number(42.0)));
assert!(tagged_value.is_tagged());

let string_value = Value::String("Not tagged".to_string());
assert!(!string_value.is_tagged());

pub fn array_len(&self) -> Option<usize>

Returns the length of the array if the value is an array, otherwise returns None.

Returns

• Some(usize) with the length of the array if the value is an Array.
• None if the value is not an Array.

Examples

use frontmatter_gen::Value;

let array_value = Value::Array(vec![Value::Number(1.0), Value::Number(2.0)]);
assert_eq!(array_value.array_len(), Some(2));

let string_value = Value::String("Not an array".to_string());
assert_eq!(string_value.array_len(), None);

pub fn to_object(self) -> Result<Frontmatter, String>

Attempts to convert the value into a Frontmatter.

Returns

• Ok(Frontmatter) if the value is an Object.
• Err(String) with an error message if the value is not an Object.

Examples

use frontmatter_gen::{Value, Frontmatter};

let object_value = Value::Object(Box::new(Frontmatter::new()));
assert!(object_value.to_object().is_ok());

let string_value = Value::String("Not an object".to_string());
assert!(string_value.to_object().is_err());

pub fn to_string_representation(&self) -> String

Converts the value to a string representation regardless of its type.

Returns

A String representation of the value.

Examples

use frontmatter_gen::Value;

let number_value = Value::Number(3.14);
assert_eq!(number_value.to_string_representation(), "3.14");

let string_value = Value::String("Hello".to_string());
assert_eq!(string_value.to_string_representation(), "\"Hello\"");

pub fn into_string(self) -> Result<String, String>

Attempts to convert the value into a String.

Returns

• Ok(String) if the value is a String.
• Err(String) with an error message if the value is not a String.

Examples

use frontmatter_gen::Value;

let string_value = Value::String("Hello".to_string());
assert_eq!(string_value.into_string(), Ok("Hello".to_string()));

let number_value = Value::Number(42.0);
assert!(number_value.into_string().is_err());

pub fn into_f64(self) -> Result<f64, String>

Attempts to convert the value into an f64.

Returns

• Ok(f64) if the value is a Number.
• Err(String) with an error message if the value is not a Number.

Examples

use frontmatter_gen::Value;

let number_value = Value::Number(3.14);
assert_eq!(number_value.into_f64(), Ok(3.14));

let string_value = Value::String("Not a number".to_string());
assert!(string_value.into_f64().is_err());

pub fn into_bool(self) -> Result<bool, String>

Attempts to convert the value into a bool.

Returns

• Ok(bool) if the value is a Boolean.
• Err(String) with an error message if the value is not a Boolean.

Examples

use frontmatter_gen::Value;

let bool_value = Value::Boolean(true);
assert_eq!(bool_value.into_bool(), Ok(true));

let string_value = Value::String("Not a boolean".to_string());
assert!(string_value.into_bool().is_err());

pub fn get_mut_array(&mut self) -> Option<&mut Vec<Value>>

Attempts to get a mutable reference to the array if the value is an array.

Returns

• Some(&mut Vec<Value>) if the value is an Array.
• None if the value is not an Array.

Examples

use frontmatter_gen::Value;

let mut array_value = Value::Array(vec![Value::Number(1.0), Value::Number(2.0)]);
if let Some(arr) = array_value.get_mut_array() {
    arr.push(Value::Number(3.0));
}
assert_eq!(array_value.array_len(), Some(3));

let mut string_value = Value::String("Not an array".to_string());
assert!(string_value.get_mut_array().is_none());

Trait Implementations

impl Clone for Value

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Value

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

Formats the value using the given formatter.

impl Default for Value

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Value

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Value

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

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

Formats the value using the given formatter.

impl From<&str> for Value

fn from(s: &str) -> Self

Converts to this type from the input type.

impl From<String> for Value

fn from(s: String) -> Self

Converts to this type from the input type.

impl From<bool> for Value

fn from(b: bool) -> Self

Converts to this type from the input type.

impl From<f64> for Value

fn from(n: f64) -> Self

Converts to this type from the input type.

impl FromIterator<Value> for Value

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

Creates a value from an iterator.

impl FromStr for Value

type Err = &'static str

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl PartialEq for Value

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Value

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 Value