statements

a.hlm

@@ -1,5 +1,9 @@
-println({
-    println("Hello");
-    return let x: num = 17 * 2 in
-        x + 1;
-} + 34);
+func add x: num -> num = x + 1;
+
+println(
+    {
+        println("Hello");
+        return let x: num = 17 * 2 in
+            add(x);
+    } + 34
+);

sketch.hlm

@@ -1,21 +0,0 @@
-println({
-    println("Hello");
-    return let x: num = 17 * 2 in
-        x + 1;
-} + 34);
-
-//----------
-
-let stack = [];
-
-push("Hello");
-console.log(pop());
-push(17)
-push(2)
-push(pop() * pop());
-push(pop() + 1);
-// [35]
-
-push(34)
-push(pop() + pop()) // [35] + 34
-console.log(pop());

src/asts/ast.rs

@@ -37,6 +37,18 @@ pub enum Expr {
     Return(Box<Self>),
 }
 
+#[derive(Clone, Debug)]
+pub enum Stmt {
+    Expr(Expr),
+    Let(Vec<(String, Type, Expr)>),
+    Func {
+        name: String,
+        args: Vec<(String, Type)>,
+        ret: Type,
+        body: Expr,
+    },
+}
+
 impl Display for Expr {
     fn fmt(&self, f: &mut Formatter) -> FmtResult {
         match self {
@@ -83,4 +95,26 @@ impl Display for Expr {
             Expr::Return(e) => write!(f, "(return {})", e),
         }
     }
+}
+
+impl Display for Stmt {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        match self {
+            Stmt::Expr(e) => write!(f, "{}", e),
+            Stmt::Let(vars) => {
+                write!(f, "(let")?;
+                for (name, ty, e) in vars {
+                    write!(f, " [{} {} {}]", name, ty, e)?;
+                }
+                write!(f, ")")
+            },
+            Stmt::Func { name, args, ret, body } => {
+                write!(f, "(defn {} [", name)?;
+                for (name, ty) in args {
+                    write!(f, "[{} {}]", name, ty)?;
+                }
+                write!(f, "] {} {})", ret, body)
+            },
+        }
+    }
 }

src/asts/js.rs

@@ -22,6 +22,18 @@ pub enum JSExpr {
     Return(Box<Self>),
 }
 
+#[derive(Clone, Debug)]
+pub enum JSStmt {
+    Expr(JSExpr),
+    Let(Vec<(String, Type, JSExpr)>),
+    Func {
+        name: String,
+        args: Vec<(String, Type)>,
+        ret: Type,
+        body: JSExpr,
+    },
+}
+
 impl Display for JSExpr {
     fn fmt(&self, f: &mut Formatter) -> FmtResult {
         match self {
@@ -89,4 +101,33 @@ impl Display for JSExpr {
             JSExpr::Return(e) => write!(f, "return {}", e),
         }
     }
+}
+
+impl Display for JSStmt {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        match self {
+            JSStmt::Expr(e) => write!(f, "{}", e),
+            JSStmt::Let(vars) => {
+                write!(f, "let ")?;
+                for (i, (name, _ty, e)) in vars.iter().enumerate() {
+                    if i > 0 {
+                        write!(f, ", ")?;
+                    }
+                    write!(f, "{} = {}", name, e)?;
+                }
+                write!(f, ";")
+            },
+            JSStmt::Func { name, args, ret: _, body } => {
+                // const name = (args) => body;
+                write!(f, "const {} = (", name)?;
+                for (i, (name, _ty)) in args.iter().enumerate() {
+                    if i > 0 {
+                        write!(f, ", ")?;
+                    }
+                    write!(f, "{}", name)?;
+                }
+                write!(f, ") => {};", body)
+            },
+        }
+    }
 }

src/asts/past.rs

@@ -49,6 +49,7 @@ pub enum PStmt {
     Func {
         name: String,
         args: Vec<(String, Type)>,
+        ret: Type,
         body: Box<Spanned<PExpr>>,
     },
 }

src/main.rs

@@ -8,7 +8,7 @@ use std::io::Write;
 use args::Options;
 use read::parse::{lex, parse};
 use structopt::StructOpt;
-use trans::low::{translate_expr, translate_js};
+use trans::low::{translate_stmt, translate_js_stmt};
 
 fn main() {
     let opt = Options::from_args();
@@ -17,15 +17,15 @@ fn main() {
     let (tokens, lex_errs) = lex(src.to_owned());
 
     let parse_errs = if let Some(tokens) = tokens {
-        let (ast, parse_errs) = parse(tokens, src.len());
+        let (past, parse_errs) = parse(tokens, src.len());
 
-        if let Some(ast) = ast {
-            let nexprs = ast.into_iter().map(|(e, _)| translate_expr(e)).collect::<Vec<_>>();
-            let jsexprs = nexprs.into_iter().map(translate_js).collect::<Vec<_>>();
+        if let Some(past) = past {
+            let ast = past.into_iter().map(|(e, _)| translate_stmt(e)).collect::<Vec<_>>();
+            let js = ast.into_iter().map(translate_js_stmt).collect::<Vec<_>>();
 
             let mut file = std::fs::File::create(opt.output.unwrap_or("out.js".into()))
                 .expect("Failed to create file");
-            let s = jsexprs
+            let s = js
                 .into_iter()
                 .map(|e| {
                     let s = format!("{}", e);

src/read/parse.rs

@@ -442,11 +442,44 @@ pub fn exprs_parser() -> impl P<Vec<Spanned<PExpr>>> {
         .repeated()
 }
 
+pub fn stmt_parser() -> impl P<Spanned<PStmt>> {
+    let func = just(Token::Func)
+        .ignore_then(symbol_parser())
+        .then(
+            symbol_parser()
+            .then_ignore(just(Token::Colon))
+            .then(type_parser())
+            .separated_by(just(Token::Comma))
+        )
+        .then_ignore(just(Token::Arrow))
+        .then(type_parser())
+        .then_ignore(just(Token::Assign))
+        .then(expr_parser().map(Box::new))
+        .map(|(((name, args), ret), body)| PStmt::Func {
+            name,
+            args,
+            ret,
+            body,
+        });
+
+    let expr = expr_parser().map(PStmt::Expr);
+
+    func
+    .or(expr)
+    .map_with_span(|s, span| (s, span))
+}
+
+pub fn stmts_parser() -> impl P<Vec<Spanned<PStmt>>> {
+    stmt_parser()
+        .then_ignore(just(Token::Semicolon))
+        .repeated()
+}
+
 pub fn parse(
     tokens: Vec<Spanned<Token>>,
     len: usize,
-) -> (Option<Vec<Spanned<PExpr>>>, Vec<Simple<Token>>) {
-    let (ast, parse_error) = exprs_parser()
+) -> (Option<Vec<Spanned<PStmt>>>, Vec<Simple<Token>>) {
+    let (ast, parse_error) = stmts_parser()
     .then_ignore(end())
     .parse_recovery(Stream::from_iter(len..len + 1, tokens.into_iter()));
 

src/trans/low.rs

@@ -4,6 +4,19 @@ use crate::asts::{
     js::*,
 };
 
+pub fn translate_stmt(stmt: PStmt) -> Stmt {
+    match stmt {
+        PStmt::Expr(e) => Stmt::Expr(translate_expr(e.0)),
+        PStmt::Let(vars) => todo!(),
+        PStmt::Func { name, args, ret, body } => Stmt::Func {
+            name,
+            args,
+            ret,
+            body: translate_expr(body.0),
+        },
+    }
+}
+
 pub fn translate_expr(expr: PExpr) -> Expr {
     match expr {
         PExpr::Error => panic!("Error in expression!"),
@@ -77,7 +90,20 @@ pub fn translate_expr(expr: PExpr) -> Expr {
     }
 }
 
-pub fn translate_js(expr: Expr) -> JSExpr {
+pub fn translate_js_stmt(stmt: Stmt) -> JSStmt {
+    match stmt {
+        Stmt::Expr(e) => JSStmt::Expr(translate_js_expr(e)),
+        Stmt::Let(vars) => todo!(),
+        Stmt::Func { name, args, ret, body } => JSStmt::Func {
+            name,
+            args,
+            ret,
+            body: translate_js_expr(body),
+        },
+    }
+}
+
+pub fn translate_js_expr(expr: Expr) -> JSExpr {
     match expr {
         Expr::Lit(l) => match l {
             Literal::Num(n)  => JSExpr::Lit(JSLiteral::Num(n)),
@@ -85,12 +111,12 @@ pub fn translate_js(expr: Expr) -> JSExpr {
             Literal::Bool(b) => JSExpr::Lit(JSLiteral::Bool(b)),
         },
         Expr::Sym(s) => JSExpr::Sym(s),
-        Expr::Vec(v) => JSExpr::Array(v.into_iter().map(translate_js).collect()),
+        Expr::Vec(v) => JSExpr::Array(v.into_iter().map(translate_js_expr).collect()),
 
         Expr::UnaryOp(op, e) => JSExpr::Op(match op {
             UnaryOp::Neg => "-",
             UnaryOp::Not => "!",
-        }, Box::new(translate_js(*e)), None),
+        }, Box::new(translate_js_expr(*e)), None),
         Expr::BinaryOp(op, e1, e2) => JSExpr::Op(match op {
             BinaryOp::Add => "+",
             BinaryOp::Sub => "-",
@@ -107,7 +133,7 @@ pub fn translate_js(expr: Expr) -> JSExpr {
 
             BinaryOp::And => "&&",
             BinaryOp::Or  => "||",
-        }, Box::new(translate_js(*e1)), Some(Box::new(translate_js(*e2)))),
+        }, Box::new(translate_js_expr(*e1)), Some(Box::new(translate_js_expr(*e2)))),
 
         Expr::Call(f, args) => {
             match *f {
@@ -117,25 +143,25 @@ pub fn translate_js(expr: Expr) -> JSExpr {
                             JSExpr::Method(
                                 Box::new(JSExpr::Sym("console".to_string())),
                                 "log".to_string(),
-                                args.into_iter().map(translate_js).collect(),
+                                args.into_iter().map(translate_js_expr).collect(),
                             )
                         },
                         _ => JSExpr::Call(
-                            Box::new(translate_js(*f)),
-                            args.into_iter().map(translate_js).collect(),
+                            Box::new(translate_js_expr(*f)),
+                            args.into_iter().map(translate_js_expr).collect(),
                         ),
                     }
                 },
                 _ => JSExpr::Call(
-                    Box::new(translate_js(*f)),
-                    args.into_iter().map(translate_js).collect(),
+                    Box::new(translate_js_expr(*f)),
+                    args.into_iter().map(translate_js_expr).collect(),
                 ),
             }
         }
         Expr::Lambda { args, body } => JSExpr::Lambda {
             args,
-            body: body.into_iter().map(translate_js).collect(),
+            body: body.into_iter().map(translate_js_expr).collect(),
         },
-        Expr::Return(e) => JSExpr::Return(Box::new(translate_js(*e))),
+        Expr::Return(e) => JSExpr::Return(Box::new(translate_js_expr(*e))),
     }
 }