Struct PromptTemplate 

pub struct PromptTemplate { /* private fields */ }

A prompt template with variable placeholders.

Variables are denoted with double curly braces: {{variable_name}}

Implementations

impl PromptTemplate

pub fn new(template: impl Into<String>) -> Self

Create a new template, extracting variable placeholders.

Example

let template = PromptTemplate::new("Hello, {{name}}!");
assert!(template.variables().contains("name"));

pub fn variables(&self) -> &HashSet<String>

Get the set of required variables.

pub fn has_variables(&self) -> bool

Check if this template has any variables.

pub fn raw(&self) -> &str

Get the raw template string.

pub fn render(&self, values: &HashMap<String, String>) -> Result<String>

Render the template with the given values.

Errors

Returns an error if any required variable is missing from the values map.

Example

let template = PromptTemplate::new("Hello, {{name}}!");
let mut values = HashMap::new();
values.insert("name".to_string(), "World".to_string());
assert_eq!(template.render(&values)?, "Hello, World!");

pub fn render_with_defaults( &self, values: &HashMap<String, String>, defaults: &HashMap<String, String>, ) -> String

Render the template, using defaults for missing variables.

Variables not in values will be replaced with empty string or their value from defaults if provided.

pub fn render_partial(&self, values: &HashMap<String, String>) -> String

Render keeping unmatched variables as-is.

Useful for partial template expansion.

pub fn validate(&self, values: &HashMap<String, String>) -> Result<()>

Validate that all required variables are present.

Trait Implementations

impl Clone for PromptTemplate

fn clone(&self) -> PromptTemplate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PromptTemplate

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

Formats the value using the given formatter.