monkeyinterpreter/
lib.rs

1mod ast;
2mod evaluator;
3mod lexer;
4mod object;
5mod parser;
6mod token;
7
8use std::error::Error;
9
10use ast::Program;
11use evaluator::Evaluator;
12use lexer::Lexer;
13use object::{Environment, MutableEnvironment};
14use parser::Parser;
15
16const MONKEY_FACE: &str = r#"
17            __,__
18   .--.  .-"     "-.  .--.
19  / .. \/  .-. .-.  \/ .. \
20 | |  '|  /   Y   \  |'  | |
21 | \   \  \ 0 | 0 /  /   / |
22  \ '- ,\.-"""""""-./, -' /
23   ''-' /_   ^ ^   _\ '-''
24       |  \._   _./  |
25       \   \ '~' /   /
26        '._ '-=-' _.'
27           '-----'
28"#;
29
30pub struct Interpreter {
31    environment: MutableEnvironment,
32    evaluator: Evaluator,
33}
34
35impl Interpreter {
36    pub fn new() -> Interpreter {
37        Interpreter {
38            environment: Environment::new(),
39            evaluator: Evaluator::new(),
40        }
41    }
42
43    pub fn interpret(&mut self, input: String) -> String {
44        let lex = Lexer::new(&input);
45        let mut parser = Parser::new(lex);
46        match parser.parse_program() {
47            Err(e) => Self::format_error(Box::new(e)),
48            Ok(p) => self.evaluate_program(p),
49        }
50    }
51
52    fn format_error(error: Box<dyn Error>) -> String {
53        format!(
54            "{}\nWhoops! We ran into some monkey business here!\n  errors:\n{}",
55            MONKEY_FACE, error
56        )
57    }
58
59    fn evaluate_program(&self, program: Program) -> String {
60        match self.evaluator.eval_program(&program, &self.environment) {
61            Ok(evaluated) => format!("{}", evaluated.inspect()),
62            Err(e) => Self::format_error(Box::new(e)),
63        }
64    }
65}
monkeyinterpreter/lib.rs

monkeyinterpreter/
lib.rs
