about summary refs log tree commit diff
path: root/users/glittershark/achilles/src/interpreter/mod.rs
diff options
context:
space:
mode:
Diffstat (limited to 'users/glittershark/achilles/src/interpreter/mod.rs')
-rw-r--r--users/glittershark/achilles/src/interpreter/mod.rs182
1 files changed, 0 insertions, 182 deletions
diff --git a/users/glittershark/achilles/src/interpreter/mod.rs b/users/glittershark/achilles/src/interpreter/mod.rs
deleted file mode 100644
index a8ba2dd3acdc..000000000000
--- a/users/glittershark/achilles/src/interpreter/mod.rs
+++ /dev/null
@@ -1,182 +0,0 @@
-mod error;
-mod value;
-
-pub use self::error::{Error, Result};
-pub use self::value::{Function, Value};
-use crate::ast::hir::{Binding, Expr};
-use crate::ast::{BinaryOperator, FunctionType, Ident, Literal, Type, UnaryOperator};
-use crate::common::env::Env;
-
-#[derive(Debug, Default)]
-pub struct Interpreter<'a> {
-    env: Env<&'a Ident<'a>, Value<'a>>,
-}
-
-impl<'a> Interpreter<'a> {
-    pub fn new() -> Self {
-        Self::default()
-    }
-
-    fn resolve(&self, var: &'a Ident<'a>) -> Result<Value<'a>> {
-        self.env
-            .resolve(var)
-            .cloned()
-            .ok_or_else(|| Error::UndefinedVariable(var.to_owned()))
-    }
-
-    pub fn eval(&mut self, expr: &'a Expr<'a, Type>) -> Result<Value<'a>> {
-        let res = match expr {
-            Expr::Ident(id, _) => self.resolve(id),
-            Expr::Literal(Literal::Int(i), _) => Ok((*i).into()),
-            Expr::Literal(Literal::Bool(b), _) => Ok((*b).into()),
-            Expr::Literal(Literal::String(s), _) => Ok(s.clone().into()),
-            Expr::Literal(Literal::Unit, _) => unreachable!(),
-            Expr::UnaryOp { op, rhs, .. } => {
-                let rhs = self.eval(rhs)?;
-                match op {
-                    UnaryOperator::Neg => -rhs,
-                    _ => unimplemented!(),
-                }
-            }
-            Expr::BinaryOp { lhs, op, rhs, .. } => {
-                let lhs = self.eval(lhs)?;
-                let rhs = self.eval(rhs)?;
-                match op {
-                    BinaryOperator::Add => lhs + rhs,
-                    BinaryOperator::Sub => lhs - rhs,
-                    BinaryOperator::Mul => lhs * rhs,
-                    BinaryOperator::Div => lhs / rhs,
-                    BinaryOperator::Pow => todo!(),
-                    BinaryOperator::Equ => Ok(lhs.eq(&rhs).into()),
-                    BinaryOperator::Neq => todo!(),
-                }
-            }
-            Expr::Let { bindings, body, .. } => {
-                self.env.push();
-                for Binding { ident, body, .. } in bindings {
-                    let val = self.eval(body)?;
-                    self.env.set(ident, val);
-                }
-                let res = self.eval(body)?;
-                self.env.pop();
-                Ok(res)
-            }
-            Expr::If {
-                condition,
-                then,
-                else_,
-                ..
-            } => {
-                let condition = self.eval(condition)?;
-                if *(condition.as_type::<bool>()?) {
-                    self.eval(then)
-                } else {
-                    self.eval(else_)
-                }
-            }
-            Expr::Call { ref fun, args, .. } => {
-                let fun = self.eval(fun)?;
-                let expected_type = FunctionType {
-                    args: args.iter().map(|_| Type::Int).collect(),
-                    ret: Box::new(Type::Int),
-                };
-
-                let Function {
-                    args: function_args,
-                    body,
-                    ..
-                } = fun.as_function(expected_type)?;
-                let arg_values = function_args.iter().zip(
-                    args.iter()
-                        .map(|v| self.eval(v))
-                        .collect::<Result<Vec<_>>>()?,
-                );
-                let mut interpreter = Interpreter::new();
-                for (arg_name, arg_value) in arg_values {
-                    interpreter.env.set(arg_name, arg_value);
-                }
-                Ok(Value::from(*interpreter.eval(body)?.as_type::<i64>()?))
-            }
-            Expr::Fun {
-                type_args: _,
-                args,
-                body,
-                type_,
-            } => {
-                let type_ = match type_ {
-                    Type::Function(ft) => ft.clone(),
-                    _ => unreachable!("Function expression without function type"),
-                };
-
-                Ok(Value::from(value::Function {
-                    // TODO
-                    type_,
-                    args: args.iter().map(|(arg, _)| arg.to_owned()).collect(),
-                    body: (**body).to_owned(),
-                }))
-            }
-        }?;
-        debug_assert_eq!(&res.type_(), expr.type_());
-        Ok(res)
-    }
-}
-
-pub fn eval<'a>(expr: &'a Expr<'a, Type>) -> Result<Value<'a>> {
-    let mut interpreter = Interpreter::new();
-    interpreter.eval(expr)
-}
-
-#[cfg(test)]
-mod tests {
-    use std::convert::TryFrom;
-
-    use super::value::{TypeOf, Val};
-    use super::*;
-    use BinaryOperator::*;
-
-    fn int_lit(i: u64) -> Box<Expr<'static, Type<'static>>> {
-        Box::new(Expr::Literal(Literal::Int(i), Type::Int))
-    }
-
-    fn do_eval<T>(src: &str) -> T
-    where
-        for<'a> &'a T: TryFrom<&'a Val<'a>>,
-        T: Clone + TypeOf,
-    {
-        let expr = crate::parser::expr(src).unwrap().1;
-        let hir = crate::tc::typecheck_expr(expr).unwrap();
-        let res = eval(&hir).unwrap();
-        res.as_type::<T>().unwrap().clone()
-    }
-
-    #[test]
-    fn simple_addition() {
-        let expr = Expr::BinaryOp {
-            lhs: int_lit(1),
-            op: Mul,
-            rhs: int_lit(2),
-            type_: Type::Int,
-        };
-        let res = eval(&expr).unwrap();
-        assert_eq!(*res.as_type::<i64>().unwrap(), 2);
-    }
-
-    #[test]
-    fn variable_shadowing() {
-        let res = do_eval::<i64>("let x = 1 in (let x = 2 in x) + x");
-        assert_eq!(res, 3);
-    }
-
-    #[test]
-    fn conditional_with_equals() {
-        let res = do_eval::<i64>("let x = 1 in if x == 1 then 2 else 4");
-        assert_eq!(res, 2);
-    }
-
-    #[test]
-    #[ignore]
-    fn function_call() {
-        let res = do_eval::<i64>("let id = fn x = x in id 1");
-        assert_eq!(res, 1);
-    }
-}