added statements, but this isn't working

src/ast.rs

@@ -24,9 +24,10 @@ pub enum BinOp {
     GreaterThan,
 }
 
+#[derive(Debug, PartialEq, Clone)]
 pub enum Stmt {
     Expr(Expr),
-    Var(Identifier, Expr),
+    Let(Identifier, Expr),
     Assign(Identifier, Expr),
     If(Expr, Vec<Stmt>),
     While(Expr, Vec<Stmt>),

src/main.rs

@@ -2,10 +2,12 @@ mod ast;
 mod parser;
 
 fn main() {
-    let a = r#"1 + a < 9 - <- chan"#;
-    let (rest, res) = parser::expr(a).unwrap();
+    let a = r#"
+  if (n < 2) {
+    return n;
+  }
+  "#;
+    let (rest, res) = parser::stmt(a).unwrap();
     dbg!(res);
     dbg!(rest);
-
-    println!("Hello, world!");
 }

src/parser.rs

@@ -2,7 +2,7 @@ use nom::{
     branch::alt,
     bytes::complete::{escaped, is_not, tag, take_until},
     character::complete::{alpha1, alphanumeric1, char, multispace0, one_of, space0},
-    combinator::{cut, map, recognize, value},
+    combinator::{cut, map, opt, recognize, value},
     error::ParseError,
     multi::{fold_many0, many0, separated_list0},
     number::complete::double,
@@ -18,7 +18,6 @@ where
 {
     alt((value((), multispace0), pinline_comment, peol_comment))(i)
 }
-
 fn pinline_comment<'a, E>(i: &'a str) -> IResult<&'a str, (), E>
 where
     E: ParseError<&'a str>,
@@ -30,32 +29,33 @@ fn peol_comment<'a, E: ParseError<&'a str>>(i: &'a str) -> IResult<&'a str, (),
     value((), pair(char('/'), is_not("\n\r")))(i)
 }
 
+fn semi(i: &str) -> IResult<&str, &str> {
+    preceded(sc, tag(";"))(i)
+}
+
 fn braces<'a, P, O, E>(a: P) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
 where
     P: Parser<&'a str, O, E>,
     E: ParseError<&'a str>,
 {
-    delimited(char('{'), a, char('}'))
+    map(tuple((tag("{"), sc, a, sc, tag("}"))), |(_, _, a, _, _)| a)
 }
-
 fn parens<'a, P, O, E>(a: P) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
 where
     P: Parser<&'a str, O, E>,
     E: ParseError<&'a str>,
 {
-    delimited(
-        tuple((tag("("), recognize(sc))),
-        a,
-        tuple((recognize(sc), tag(")"))),
-    )
+    map(tuple((tag("("), sc, a, sc, tag(")"))), |(_, _, a, _, _)| a)
 }
-
 fn identifier(i: &str) -> IResult<&str, &str> {
     println!("identifier: {}", i);
+    preceded(
+        sc,
         recognize(pair(
             alt((alpha1, tag("_"))),
             many0(alt((alphanumeric1, tag("_")))),
-    ))(i)
+        )),
+    )(i)
 }
 
 fn variable(i: &str) -> IResult<&str, Expr> {
@@ -193,6 +193,113 @@ pub fn expr<'a>(i: &'a str) -> IResult<&'a str, Expr> {
     binary(i)
 }
 
+fn if_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("if: {}", i);
+    map(
+        tuple((tag("if"), sc, parens(expr), sc, braces(many0(stmt)))),
+        |(_, _, expr, _, stmts)| Stmt::If(expr, stmts),
+    )(i)
+}
+fn while_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("while: {}", i);
+    map(
+        tuple((tag("while"), sc, parens(expr), sc, braces(many0(stmt)))),
+        |(_, _, expr, _, stmts)| Stmt::While(expr, stmts),
+    )(i)
+}
+fn let_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("let: {}", i);
+    map(
+        tuple((
+            tag("let"),
+            sc,
+            identifier,
+            tuple((sc, tag("="), sc)),
+            expr,
+            semi,
+        )),
+        |(_, _, id, _, expr, _)| Stmt::Let(id.to_string(), expr),
+    )(i)
+}
+fn yield_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("yield: {}", i);
+    map(tuple((tag("yield"), semi)), |_| Stmt::Yield)(i)
+}
+fn spawn_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("spawn: {}", i);
+    map(tuple((tag("spawn"), sc, expr, semi)), |(_, _, expr, _)| {
+        Stmt::Spawn(expr)
+    })(i)
+}
+fn return_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("return: {}", i);
+    map(
+        tuple((tag("return"), sc, opt(expr), semi)),
+        |(_, _, expr, _)| Stmt::Return(expr),
+    )(i)
+}
+fn func_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("func: {}", i);
+    map(
+        tuple((
+            tag("fn"),
+            sc,
+            identifier,
+            sc,
+            alt((
+                value(vec![], tuple((char('('), sc, char(')')))),
+                delimited(
+                    char('('),
+                    separated_list0(
+                        tuple((sc, tag(","), sc)),
+                        map(identifier, |a| a.to_string()),
+                    ),
+                    char(')'),
+                ),
+            )),
+            sc,
+            braces(many0(stmt)),
+        )),
+        |(_, _, id, _, params, _, stmts)| Stmt::Func(id.to_string(), params, stmts),
+    )(i)
+}
+fn assign_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("assign: {}", i);
+    map(
+        tuple((identifier, tuple((sc, tag("="), sc)), expr, semi)),
+        |(id, _, expr, _)| Stmt::Assign(id.to_string(), expr),
+    )(i)
+}
+fn send_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("send: {}", i);
+    map(
+        tuple((expr, tuple((sc, tag("->"), sc)), identifier, semi)),
+        |(expr, _, id, _)| Stmt::Send(expr, id.to_string()),
+    )(i)
+}
+fn expr_stmt(i: &str) -> IResult<&str, Stmt> {
+    println!("expr: {}", i);
+    map(tuple((expr, semi)), |(expr, _)| Stmt::Expr(expr))(i)
+}
+
+pub fn stmt(i: &str) -> IResult<&str, Stmt> {
+    preceded(
+        sc,
+        alt((
+            if_stmt,
+            while_stmt,
+            let_stmt,
+            yield_stmt,
+            spawn_stmt,
+            return_stmt,
+            func_stmt,
+            assign_stmt,
+            send_stmt,
+            expr_stmt,
+        )),
+    )(i)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -396,4 +503,53 @@ mod tests {
         );
         assert_eq!(rest, "");
     }
+
+    #[test]
+    fn can_parse_let_stmt() {
+        let a = r#"let a = 0;"#;
+        let (rest, res) = stmt(a).unwrap();
+
+        assert_eq!(res, Stmt::Let("a".to_string(), Expr::LNum(0.0)));
+        assert_eq!(rest, "");
+    }
+
+    #[test]
+    fn can_parse_if_stmt() {
+        let a = r#"
+  if (n < 2) {
+    return n;
+  }
+"#;
+        let (rest, res) = stmt(a).unwrap();
+
+        assert_eq!(
+            res,
+            Stmt::If(
+                Expr::Binary(
+                    BinOp::LessThan,
+                    Box::new(Expr::Var("n".to_string())),
+                    Box::new(Expr::LNum(2.0)),
+                ),
+                vec![Stmt::Return(Some(Expr::Var("n".to_string())))]
+            )
+        );
+        assert_eq!(rest, "");
+    }
+
+    #[test]
+    fn can_parse_func() {
+        let a = r#"
+fn fib(n) {
+  if (n < 2) {
+    return n;
+  }
+  return fib(n - 2)
+    + fib(n - 1);
+}
+"#;
+        let (rest, res) = stmt(a).unwrap();
+
+        assert_eq!(res, Stmt::Let("a".to_string(), Expr::LNum(0.0)));
+        assert_eq!(rest, "");
+    }
 }