Struct rubble_templates_core::functions::FunctionWithContext

pub struct FunctionWithContext<F> where
    F: Fn(&[String], &mut Context) -> Result<String, SyntaxError>,  { /* fields omitted */ }

A wrapper for a Fn(&dyn Evaluator, &[String], &mut Context) -> Result<String, SyntaxError>, to be used in Evaluator.

Example:

use std::collections::HashMap;
use rubble_templates_core::evaluator::{Context, SyntaxError, Function};
use rubble_templates_core::functions::FunctionWithContext;

fn plus_function(parameters: &[String], _context: &mut Context) -> Result<String, SyntaxError> {
    Ok(
        parameters.iter()
            .map(|param|
                param.parse::<i32>().unwrap()
            )
            .sum::<i32>()
            .to_string()
    )
}

let mut functions: HashMap<String, Box<dyn Function>> = HashMap::new();
functions.insert("plus".to_string(), FunctionWithContext::new(plus_function)); // will be treated as Box<dyn Function>

Implementations

impl<F> FunctionWithContext<F> where
    F: Fn(&[String], &mut Context) -> Result<String, SyntaxError>, 

pub fn new(function: F) -> Box<FunctionWithContext<F>>

Trait Implementations

impl<F> Function for FunctionWithContext<F> where
    F: Fn(&[String], &mut Context) -> Result<String, SyntaxError>, 

fn evaluate(
    &self,
    evaluator: &dyn Evaluator,
    parameters: &[SyntaxNode],
    context: &mut Context
) -> Result<String, SyntaxError>