Remove interpreter & evaluator

src/emitter.rs

@@ -44,7 +44,7 @@ pub fn emit_injector(w: &mut dyn Write) -> std::io::Result<()>{
     Ok(())
 }
 
-pub fn emit_all(w: &mut dyn Write, ast: &Vec<parser::Stmt>, ctx: &mut LexicalContext) -> std::io::Result<()> {
+pub fn emit_all(w: &mut dyn Write, ast: &[parser::Stmt], ctx: &mut LexicalContext) -> std::io::Result<()> {
     let is_tail = ctx.is_tail;
     ctx.is_tail = false;
     if let Some((last, butlast)) = ast.split_last() {
@@ -152,7 +152,7 @@ pub fn emit_expr(w: &mut dyn Write, expr: &parser::Expr, ctx: &mut LexicalContex
 	    }
 	    let mut fun_ctx = LexicalContext::new(ctx);
 	    fun_ctx.is_tail = true;
-	    emit_all(w, body.as_ref(), &mut fun_ctx)?;
+	    emit_all(w, body, &mut fun_ctx)?;
 	    write!(w, "}}")?;
 	}
 	parser::Expr::Plus(e1, e2) => {

src/evaluator.rs

@@ -1,139 +0,0 @@
-use std::ops;
-use std::collections::HashMap;
-
-use crate::parser::{self, GuardedBlock};
-use parser::Atom;
-
-pub struct Env<'a> {
-    pub parent: Option<&'a Env<'a>>,
-    pub values: HashMap<String, Atom>
-}
-
-impl<'a> Env<'a> {
-    pub fn global() -> Self {
-        Env {
-            parent: None,
-            values: HashMap::new(),
-        }
-    }
-    pub fn child(parent: &'a Env<'a>) -> Self {
-        Env {
-            parent: Some(parent),
-            values: HashMap::new(),
-        }
-    }
-    pub fn lookup(&self, id: &str) -> Atom {
-        if let Some(a) = self.values.get(id) {
-            a.clone()
-        } else if let Some(parent) = self.parent {
-            parent.lookup(id)
-        } else {
-            panic!("Variable {} not in scope.", id)
-        }
-    }
-    pub fn set(&mut self, id: String, atom: Atom) {
-        self.values.insert(id, atom);
-    }
-}
-
-pub fn eval(ast: &parser::Stmt, env: &mut Env) {
-    match &ast {
-        parser::Stmt::BareExpr(expr) =>
-            println!("{}", eval_expr(expr, env)),
-        parser::Stmt::Assignment(id, expr) =>
-            env.set(id.clone(), eval_expr(expr, env)),
-        parser::Stmt::Conditional(guarded_blocks, default_block) => {
-            let mut matched = false;
-            for GuardedBlock { guard, block } in guarded_blocks  {
-                let res = eval_expr(guard, env);
-                match res {
-                    Atom::Bool(true) => {
-                        matched = true;
-                        for stmt in block {
-			    eval(stmt, env);
-                        }
-                        break;
-                    }
-                    Atom::Bool(false) => continue,
-                    _ => panic!("Conditional expression does not evaluate to a bool"),
-                }
-            }
-            if !matched {
-                if let Some(block) = default_block {
-		    for stmt in block {
-			eval(stmt, env);
-		    }
-                }
-            }
-        }
-        _ => todo!(),
-    }
-}
-
-pub fn eval_expr(ast: &parser::Expr, env: &Env) -> Atom {
-    match ast {
-        parser::Expr::Id(a) => env.lookup(a),
-        parser::Expr::Atom(a) => a.clone(),
-        parser::Expr::UnaryMinus(a) => -eval_expr(a, env),
-        parser::Expr::Plus(a, b) => eval_expr(a, env) + eval_expr(b, env),
-        parser::Expr::Minus(a, b) => eval_expr(a, env) - eval_expr(b, env),
-        parser::Expr::Mult(a, b) => eval_expr(a, env) * eval_expr(b, env),
-        parser::Expr::Div(a, b) => eval_expr(a, env) / eval_expr(b, env),
-        _ => panic!("Couldn't evalute expression {{ {:?} }}", ast),
-    }
-}
-
-impl ops::Neg for Atom {
-    type Output = Self;
-
-    fn neg(self) -> Self {
-        match self {
-            Atom::Num(a) => Atom::Num(-a),
-            _ => panic!("Can't negate non-numeral type!"),
-        }
-    }
-}
-
-impl ops::Add for Atom {
-    type Output = Self;
-
-    fn add(self, other: Self) -> Self {
-        match (self, other) {
-            (Atom::Num(a), Atom::Num(b)) => Atom::Num(a + b),
-            _ => panic!("Can't add non-numeral types!"),
-        }
-    }
-}
-
-impl ops::Sub for Atom {
-    type Output = Self;
-
-    fn sub(self, other: Self) -> Self {
-        match (self, other) {
-            (Atom::Num(a), Atom::Num(b)) => Atom::Num(a - b),
-            _ => panic!("Can't subtract non-numeral types!"),
-        }
-    }
-}
-
-impl ops::Mul for Atom {
-    type Output = Self;
-
-    fn mul(self, other: Self) -> Self {
-        match (self, other) {
-            (Atom::Num(a), Atom::Num(b)) => Atom::Num(a * b),
-            _ => panic!("Can't multiply non-numeral types!"),
-        }
-    }
-}
-
-impl ops::Div for Atom {
-    type Output = Self;
-
-    fn div(self, other: Self) -> Self {
-        match (self, other) {
-            (Atom::Num(a), Atom::Num(b)) => Atom::Num(a / b),
-            _ => panic!("Can't divide non-numeral types!"),
-        }
-    }
-}

src/main.rs

@@ -1,5 +1,4 @@
 mod parser;
-mod evaluator;
 mod emitter;
 mod internal;
 
@@ -11,11 +10,11 @@ use std::fs::File;
 use std::path::PathBuf;
 
 #[derive(Parser, Debug)]
-#[clap(author, version, about = "Interpreter for Deelang")]
+#[clap(author, version, about = "Compiler for Deelang")]
 struct Cli {
-    #[clap(help="Specify a file to run")]
+    #[clap(help="Specify a file to compile")]
     file: Option<PathBuf>,
-    #[clap(short, long, help="Only parse, do not evaluate")]
+    #[clap(short, long, help="Emit a parse tree")]
     parse: bool,
     #[clap(short, long, help="Cross-compile to ECMAScript")]
     ecmascript: bool,
@@ -24,7 +23,6 @@ struct Cli {
 }
 
 fn repl(cli: &Cli) {
-    let mut global = evaluator::Env::global();
     let mut toplevel = emitter::LexicalContext::toplevel();
     let mut out = io::stdout();
     loop {
@@ -35,10 +33,8 @@ fn repl(cli: &Cli) {
             println!("{:#?}", tree);
         } else if cli.ecmascript {
 	    emitter::emit(&mut out, &tree, &mut toplevel).ok();
-	} else {
-            evaluator::eval(&tree, &mut global);
-        }
 	}
+    };
 }
 
 fn script(cli: &Cli) {
@@ -57,8 +53,6 @@ fn script(cli: &Cli) {
 	emitter::emit_injector(&mut out).ok();
 	let mut toplevel = emitter::LexicalContext::toplevel();
 	emitter::emit_all(&mut out, &tree, &mut toplevel).ok();
-    } else {
-        todo!();
     }
 }