Implement REPL resolves #5
parent
390c5d1b48
commit
aaa93d8593
|
@ -1,5 +1,5 @@
|
|||
use crate::parser::Datum;
|
||||
use crate::parser::make_symbol;
|
||||
use crate::parser::Datum;
|
||||
use crate::primitives;
|
||||
use std::mem;
|
||||
|
||||
|
@ -8,10 +8,12 @@ type Frame = Vec<Mapping>;
|
|||
pub type Env = Vec<Frame>;
|
||||
|
||||
pub fn get_global_environment() -> Env {
|
||||
vec![vec![(make_symbol("+"), Datum::Procedure(primitives::add)),
|
||||
(make_symbol("*"), Datum::Procedure(primitives::mul)),
|
||||
(make_symbol("-"), Datum::Procedure(primitives::sub)),
|
||||
(make_symbol("="), Datum::Procedure(primitives::eq))]]
|
||||
vec![vec![
|
||||
(make_symbol("+"), Datum::Procedure(primitives::add)),
|
||||
(make_symbol("*"), Datum::Procedure(primitives::mul)),
|
||||
(make_symbol("-"), Datum::Procedure(primitives::sub)),
|
||||
(make_symbol("="), Datum::Procedure(primitives::eq)),
|
||||
]]
|
||||
}
|
||||
|
||||
pub fn lookup_variable_value(var: &Datum, env: &Env) -> Datum {
|
||||
|
@ -79,4 +81,4 @@ pub fn extend_environment(vars: Datum, vals: Datum, env: &mut Env) -> Datum {
|
|||
pub fn shrink_environment(env: &mut Env) -> Datum {
|
||||
env.pop();
|
||||
Datum::Unspecified
|
||||
}
|
||||
}
|
||||
|
|
|
@ -1,9 +1,9 @@
|
|||
use crate::parser::Datum;
|
||||
use crate::parser::Datum::*;
|
||||
use crate::parser::make_symbol;
|
||||
use crate::environment;
|
||||
use crate::environment::Env;
|
||||
|
||||
use crate::parser::make_symbol;
|
||||
use crate::parser::Datum;
|
||||
use crate::parser::Datum::*;
|
||||
|
||||
fn is_true(exp: &Datum) -> bool {
|
||||
match exp {
|
||||
Boolean(b) => *b,
|
||||
|
@ -16,7 +16,7 @@ fn is_true(exp: &Datum) -> bool {
|
|||
fn has_tag(vec: &Vec<Datum>, tag: &str) -> bool {
|
||||
if vec.len() == 0 {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
if let Symbol(s) = &vec[0] {
|
||||
if s == tag {
|
||||
return true;
|
||||
|
@ -49,7 +49,7 @@ fn interpret_define(args: &Vec<Datum>, env: &mut Env) -> Datum {
|
|||
let var = &args[1];
|
||||
let val = interpret(&args[2], env);
|
||||
environment::define_variable(var, val, env)
|
||||
},
|
||||
}
|
||||
List(v) => {
|
||||
// procedure definition
|
||||
let definition_var = &v[0];
|
||||
|
@ -65,8 +65,8 @@ fn interpret_define(args: &Vec<Datum>, env: &mut Env) -> Datum {
|
|||
let lambda_body = Datum::List(args[2..].to_vec());
|
||||
let lambda = Datum::List(vec![make_symbol("lambda"), lambda_parameters, lambda_body]);
|
||||
environment::define_variable(definition_var, lambda, env)
|
||||
},
|
||||
_ => panic!("INTERPRET-DEFINE -- cannot define {:?}", args)
|
||||
}
|
||||
_ => panic!("INTERPRET-DEFINE -- cannot define {:?}", args),
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -106,8 +106,8 @@ fn interpret_application(vec: &Vec<Datum>, env: &mut Env) -> Datum {
|
|||
}
|
||||
environment::shrink_environment(env);
|
||||
r
|
||||
},
|
||||
_ => panic!("INTERPRET-APPLICATION -- not-aplicable {:?}", args[0])
|
||||
}
|
||||
_ => panic!("INTERPRET-APPLICATION -- not-aplicable {:?}", args[0]),
|
||||
}
|
||||
}
|
||||
|
||||
|
|
40
src/main.rs
40
src/main.rs
|
@ -1,16 +1,46 @@
|
|||
mod environment;
|
||||
mod interpreter;
|
||||
mod lexer;
|
||||
mod parser;
|
||||
mod primitives;
|
||||
mod environment;
|
||||
use std::io;
|
||||
use std::io::prelude::*;
|
||||
|
||||
fn main() {
|
||||
// let scm_code = "(if (= 1 1) (+ 1 1) (* 2 3 4))";
|
||||
// let scm_code = "(begin (define a (+ 2 2)) (* 3 2) (* a a a))";
|
||||
let scm_code = "(begin (define (f n) (if (= n 1) 1 (* n (f (- n 1))))) (f 10))";
|
||||
fn repl() {
|
||||
let mut env = environment::get_global_environment();
|
||||
loop {
|
||||
let mut input = String::new();
|
||||
print!(" ]=> ");
|
||||
io::stdout().flush().ok().expect("Could not flush stdout");
|
||||
match io::stdin().read_line(&mut input) {
|
||||
Ok(_) => {
|
||||
let tokens = lexer::read(&input);
|
||||
let datum = parser::parse(tokens);
|
||||
let result = interpreter::interpret(&datum, &mut env);
|
||||
println!("{:?}", result);
|
||||
}
|
||||
Err(error) => println!("error: {}", error),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn interpret_code(scm_code: &str) {
|
||||
let tokens = lexer::read(scm_code);
|
||||
let datum = parser::parse(tokens);
|
||||
let mut env = environment::get_global_environment();
|
||||
let result = interpreter::interpret(&datum, &mut env);
|
||||
println!("{:?}", result);
|
||||
}
|
||||
|
||||
fn interpret_file() {}
|
||||
|
||||
fn main() {
|
||||
// let scm_code = "(begin (define (f n) (if (= n 1) 1 (* n (f (- n 1))))) (f 10))";
|
||||
let scm_code = "";
|
||||
|
||||
if scm_code.len() > 0 {
|
||||
interpret_code(scm_code);
|
||||
} else {
|
||||
repl();
|
||||
}
|
||||
}
|
||||
|
|
|
@ -66,8 +66,12 @@ pub fn eq(args: Vec<Datum>) -> Datum {
|
|||
for i in 2..args.len() {
|
||||
let current = &args[i];
|
||||
match (first, current) {
|
||||
(Boolean(b1), Boolean(b2)) => {return Boolean(b1 == b2);},
|
||||
(Number(n1), Number(n2)) => {return Boolean(n1 == n2);},
|
||||
(Boolean(b1), Boolean(b2)) => {
|
||||
return Boolean(b1 == b2);
|
||||
}
|
||||
(Number(n1), Number(n2)) => {
|
||||
return Boolean(n1 == n2);
|
||||
}
|
||||
_ => {
|
||||
println!("{:?} is not equal to {:?}", first, current);
|
||||
return Boolean(false);
|
||||
|
@ -76,4 +80,4 @@ pub fn eq(args: Vec<Datum>) -> Datum {
|
|||
}
|
||||
Boolean(true)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
Loading…
Reference in New Issue