parsed ast of basic application

src/ast/expression.rs

@@ -0,0 +1,23 @@
+use crate::token::{LiteralKind, Number, Token};
+
+#[derive(Debug)]
+pub enum Expression {
+    Literal {
+        literal: LiteralKind,
+        token: Token,
+    },
+    Unary,
+    Binary,
+    Call {
+        callee: Box<Expression>,
+        arguments: Vec<Expression>,
+    },
+    Grouping,
+    Variable {
+        name: String,
+        token: Token,
+    },
+}
+
+pub enum BinaryOperator {}
+pub enum UnaryOperator {}

src/ast/mod.rs

@@ -1,5 +1,9 @@
+mod expression;
+pub use expression::*;
+
 use crate::token::Token;
 
+#[derive(Debug)]
 pub struct Module {
     pub statements: Vec<Statement>,
 }
@@ -19,13 +23,3 @@ pub struct ParameterDeclaration {
     pub name: Token,
     pub typename: Token,
 }
-
-#[derive(Debug)]
-pub enum Expression {
-    Identifier(Token),
-    FunctionCall {
-        function: Box<Expression>,
-        arguments: Vec<Expression>,
-        return_type: Option<Token>,
-    },
-}

src/lexer.rs

@@ -31,6 +31,7 @@ impl Lexer {
             self.next_token();
         }
         self.clean_newlines();
+        self.push(TokenKind::EndOfFile);
         self.tokens
     }
 
@@ -118,9 +119,6 @@ impl Lexer {
                     break;
                 }
             }
-            if self.is_eof() {
-                todo!("Not sure if handling is necessary")
-            }
             let s = self.current_scan(0, 0);
             if let Ok(k) = TryInto::<KeywordKind>::try_into(s.as_str()) {
                 self.push(TokenKind::Keyword(k));

src/main.rs

@@ -7,7 +7,6 @@ mod parse;
 mod token;
 
 fn main() {
-    use format::Formatter;
     use lexer::Lexer;
     const BASIC: &str = r#"
 function hello(name: string){
@@ -22,6 +21,6 @@ hello();
     let lexer = Lexer::new(BASIC, Some("basic.file".to_string()));
     let tokens = lexer.lex();
     let mut parser = Parser::new(tokens);
-    let statement = parser.statement();
-    println!("{statement:?}");
+    let module = parser.module();
+    println!("{module:?}");
 }

src/parse/expression.rs

@@ -0,0 +1,74 @@
+use crate::{ast, expect_token, get_token, match_token, token::TokenKind};
+
+use super::Parser;
+
+impl Parser {
+    pub fn expression(&mut self) -> ast::Expression {
+        self.call()
+    }
+    fn equality(&mut self) -> ast::Expression {
+        todo!()
+    }
+    fn comparison(&mut self) -> ast::Expression {
+        todo!()
+    }
+    fn term(&mut self) -> ast::Expression {
+        todo!()
+    }
+    fn factor(&mut self) -> ast::Expression {
+        todo!()
+    }
+    fn unary(&mut self) -> ast::Expression {
+        todo!()
+    }
+    fn call(&mut self) -> ast::Expression {
+        let mut e = self.primary();
+
+        if match_token!(self, TokenKind::LeftParen) {
+            let mut arguments = Vec::new();
+            while !match_token!(self, TokenKind::RightParen) {
+                arguments.push(self.expression());
+                if !match_token!(self, TokenKind::Comma) {
+                    expect_token!(self, TokenKind::RightParen, "RightParen");
+                    break;
+                }
+            }
+            e = ast::Expression::Call {
+                callee: Box::new(e),
+                arguments,
+            }
+        }
+
+        e
+    }
+    fn primary(&mut self) -> ast::Expression {
+        if let Some((token, TokenKind::Literal(literal))) = get_token!(self, TokenKind::Literal(_))
+        {
+            return ast::Expression::Literal { literal, token };
+        }
+
+        if let Some((token, TokenKind::Identifier(name))) =
+            get_token!(self, TokenKind::Identifier(_))
+        {
+            return ast::Expression::Variable { name, token };
+        }
+
+        todo!("Unknown expression {:?}", self.peek())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{ast::Expression, lexer::Lexer, parse::Parser, token::TokenKind};
+
+    #[test]
+    fn test_identifier() {
+        let tokens = Lexer::new("my_var", None).lex();
+        let mut parser = Parser::new(tokens);
+        let expr = parser.expression();
+        let Expression::Variable { name, token } = expr else {
+            panic!()
+        };
+        assert_eq!("my_var", name)
+    }
+}

src/parse/macros.rs

@@ -1,9 +1,10 @@
 #[macro_export]
 macro_rules! expect_token {
-    ($self:ident, $expect:pat) => {
+    ($self:ident, $expect:pat, $help:literal) => {
         let t = $self.consume();
-        if !matches!(t.kind, $expect) {
-            todo!("Expected token, found {:?}", t.kind)
+        let kind = t.as_ref().map(|t| &t.kind);
+        if !matches!(kind, Some($expect)) {
+            todo!("Expected token ({}), found {:?}.", $help, t)
         }
     };
 }
@@ -12,10 +13,11 @@ macro_rules! expect_token {
 macro_rules! expect_identifier {
     ($self:ident) => {{
         let t = $self.consume();
-        if !matches!(t.kind, TokenKind::Identifier(_)) {
-            todo!("Expected token, found {:?}", t.kind)
+        let kind = t.as_ref().map(|t| &t.kind);
+        if !matches!(kind, Some(TokenKind::Identifier(_))) {
+            todo!("Expected identifier, found {:?}", t);
         }
-        t
+        t.unwrap()
     }};
 }
 
@@ -23,10 +25,11 @@ macro_rules! expect_identifier {
 macro_rules! expect_any_keyword {
     ($self:ident) => {{
         let t = $self.consume();
-        if !matches!(t.kind, TokenKind::Keyword(_)) {
-            todo!("Expected token, found {:?}", t.kind)
+        let kind = t.as_ref().map(|t| &t.kind);
+        if !matches!(kind, Some(TokenKind::Keyword(_))) {
+            todo!("Expected keyword, found {:?}", t)
         }
-        t
+        t.unwrap()
     }};
 }
 
@@ -34,8 +37,9 @@ macro_rules! expect_any_keyword {
 macro_rules! expect_keyword {
     ($self:ident, $keyword:pat) => {
         let t = $self.consume();
-        if !matches!(t.kind, TokenKind::Keyword($keyword)) {
-            todo!("Expected token, found {:?}", t.kind)
+        let kind = t.as_ref().map(|t| &t.kind);
+        if !matches!(kind, Some(TokenKind::Keyword($keyword))) {
+            todo!("Expected keyword, found {:?}", t)
         }
     };
 }
@@ -43,13 +47,39 @@ macro_rules! expect_keyword {
 #[macro_export]
 macro_rules! peek_keyword {
     ($self:ident, $keyword:pat) => {
-        matches!($self.peek().kind, TokenKind::Keyword($keyword))
+        matches!(
+            $self.peek().map(|t| &t.kind),
+            Some(TokenKind::Keyword($keyword))
+        )
     };
 }
 
 #[macro_export]
 macro_rules! peek_match {
     ($self:ident, $p:pat) => {
-        matches!($self.peek().kind, $p)
+        matches!($self.peek().map(|t| &t.kind), Some($p))
     };
 }
+
+#[macro_export]
+macro_rules! match_token {
+    ($self:ident, $p:pat) => {{
+        let b = matches!($self.peek().map(|t| &t.kind), Some($p));
+        if b {
+            $self.consume();
+        }
+        b
+    }};
+}
+
+#[macro_export]
+macro_rules! get_token {
+    ($self:ident, $p:pat) => {{
+        let b = matches!($self.peek().map(|t| &t.kind), Some($p));
+        if b {
+            $self.consume().map(|t| (t.clone(), t.kind))
+        } else {
+            None
+        }
+    }};
+}

src/parse/mod.rs

@@ -1,8 +1,9 @@
+mod expression;
 mod macros;
 
 use crate::{
-    ast, expect_any_keyword, expect_identifier, expect_keyword, expect_token, peek_keyword,
-    peek_match,
+    ast, expect_any_keyword, expect_identifier, expect_keyword, expect_token, match_token,
+    peek_keyword, peek_match,
     token::{KeywordKind, Token, TokenKind},
 };
 
@@ -13,26 +14,40 @@ pub struct Parser {
 
 impl Parser {
     pub fn new(tokens: Vec<Token>) -> Parser {
+        let tokens = tokens
+            .into_iter()
+            .filter(|t| !matches!(t.kind, TokenKind::NewLine))
+            .collect::<Vec<_>>();
+
         Self { tokens, current: 0 }
     }
 
-    pub fn statement(&mut self) -> ast::Statement {
+    pub fn module(&mut self) -> ast::Module {
+        let mut statements = Vec::new();
+        while !match_token!(self, TokenKind::EndOfFile) {
+            let s = self.statement();
+            println!("Parsed Statement {s:?}");
+            statements.push(s);
+        }
+        ast::Module { statements }
+    }
+
+    fn statement(&mut self) -> ast::Statement {
         if peek_keyword!(self, KeywordKind::function) {
             return self.function_declaration();
         }
-        return self.expression_statement();
-        todo!("No statement");
+        self.expression_statement()
     }
 
     fn function_declaration(&mut self) -> ast::Statement {
         expect_keyword!(self, KeywordKind::function);
         let id = expect_identifier!(self);
-        expect_token!(self, TokenKind::LeftParen);
+        expect_token!(self, TokenKind::LeftParen, "LeftParen");
 
         let mut parameters = Vec::new();
         while peek_match!(self, TokenKind::Identifier(_)) {
             let name = expect_identifier!(self);
-            expect_token!(self, TokenKind::Colon);
+            expect_token!(self, TokenKind::Colon, "Colon");
             let typename = expect_any_keyword!(self);
             let parameter = ast::ParameterDeclaration {
                 name: name.clone(),
@@ -41,9 +56,9 @@ impl Parser {
             parameters.push(parameter);
         }
 
-        expect_token!(self, TokenKind::RightParen);
+        expect_token!(self, TokenKind::RightParen, "RightParen");
 
-        expect_token!(self, TokenKind::LeftCurly);
+        expect_token!(self, TokenKind::LeftCurly, "LeftCurly");
 
         let mut statements = Vec::new();
         while !peek_match!(self, TokenKind::RightCurly) {
@@ -51,7 +66,7 @@ impl Parser {
             statements.push(statement);
         }
 
-        expect_token!(self, TokenKind::RightCurly);
+        expect_token!(self, TokenKind::RightCurly, "RightCurly");
 
         ast::Statement::FunctionDeclaration {
             name: id.clone(),
@@ -61,17 +76,19 @@ impl Parser {
     }
 
     fn expression_statement(&mut self) -> ast::Statement {
-        todo!()
+        let e = self.expression();
+        expect_token!(self, TokenKind::Semicolon, "Semicolon");
+        ast::Statement::Expression(e)
     }
 }
 
 impl Parser {
-    fn peek(&self) -> &Token {
-        &self.tokens[self.current]
+    fn peek(&self) -> Option<&Token> {
+        self.tokens.get(self.current)
     }
-    fn consume(&mut self) -> Token {
-        let token = &self.tokens[self.current];
+    fn consume(&mut self) -> Option<Token> {
+        let token = self.peek().cloned();
         self.current += 1;
-        token.clone()
+        token
     }
 }