parse booleans and heavy refactoring

Cargo.toml

@@ -2,7 +2,3 @@
 name = "monkeyrs"
 version = "0.1.0"
 edition = "2021"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]

src/ast.rs

@@ -3,19 +3,122 @@ use std::{
     rc::Rc,
 };
 
-use crate::token::{Token, TokenType};
+use crate::token::TokenType;
 
-pub trait Node: Debug {}
+#[derive(Debug, PartialEq, Eq)]
+pub enum NodeType {
+    Program,
+    LetStatement,
+    ReturnStatement,
+    ExpressionStatement,
+    IdentifierExpression,
+    IntegerLiteralExpression,
+    PrefixExpression,
+    InfixExpression,
+    BooleanExpression,
+    DummyExpression,
+}
+
+#[macro_export]
+macro_rules! node_type_eq {
+    ( $x:expr, $y:expr ) => {{
+        if $x.node_type() != $y.node_type() {
+            false
+        } else {
+            match $x.node_type() {
+                NodeType::Program => unreachable!(),
+                NodeType::DummyExpression => true,
+                NodeType::BooleanExpression => {
+                    let __x = unsafe { $x.downcast::<Boolean>() };
+                    let __y = unsafe { $y.downcast::<Boolean>() };
+                    __x == __y
+                }
+                NodeType::ExpressionStatement => {
+                    let __x = unsafe { $x.downcast::<ExpressionStatement>() };
+                    let __y = unsafe { $y.downcast::<ExpressionStatement>() };
+                    __x == __y
+                }
+                NodeType::LetStatement => {
+                    let __x = unsafe { $x.downcast::<Let>() };
+                    let __y = unsafe { $y.downcast::<Let>() };
+                    __x == __y
+                }
+                NodeType::ReturnStatement => {
+                    let __x = unsafe { $x.downcast::<Return>() };
+                    let __y = unsafe { $y.downcast::<Return>() };
+                    __x == __y
+                }
+                NodeType::InfixExpression => {
+                    let __x = unsafe { $x.downcast::<Infix>() };
+                    let __y = unsafe { $y.downcast::<Infix>() };
+                    __x == __y
+                }
+                NodeType::PrefixExpression => {
+                    let __x = unsafe { $x.downcast::<Prefix>() };
+                    let __y = unsafe { $y.downcast::<Prefix>() };
+                    __x == __y
+                }
+                NodeType::IdentifierExpression => {
+                    let __x = unsafe { $x.downcast::<Identifier>() };
+                    let __y = unsafe { $y.downcast::<Identifier>() };
+                    __x == __y
+                }
+                NodeType::IntegerLiteralExpression => {
+                    let __x = unsafe { $x.downcast::<IntegerLiteral>() };
+                    let __y = unsafe { $y.downcast::<IntegerLiteral>() };
+                    __x == __y
+                }
+            }
+        }
+    }};
+}
+
+pub trait Node: Debug {
+    fn node_type(&self) -> NodeType;
+}
 
 pub trait Statement: Node {}
 
+impl dyn Statement {
+    unsafe fn downcast<T>(&self) -> &T {
+        &*(self as *const dyn Statement as *const T)
+    }
+}
+
 pub trait Expression: Node {}
 
+impl dyn Expression {
+    unsafe fn downcast<T>(&self) -> &T {
+        &*(self as *const dyn Expression as *const T)
+    }
+}
+
 pub struct Program {
     pub statements: Vec<Rc<dyn Statement>>,
 }
 
-impl Node for Program {}
+impl PartialEq for Program {
+    fn eq(&self, other: &Self) -> bool {
+        if self.statements.len() != other.statements.len() {
+            return false;
+        }
+        let mut other_iter = other.statements.iter();
+        for stmt in self.statements.iter() {
+            let other = other_iter.next().unwrap();
+
+            if !node_type_eq!(stmt, other) {
+                return false;
+            }
+        }
+        true
+    }
+}
+
+impl Node for Program {
+    fn node_type(&self) -> NodeType {
+        NodeType::Program
+    }
+}
 
 impl Debug for Program {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -33,56 +136,97 @@ impl Debug for Program {
 
 #[derive(Debug)]
 pub struct Let {
-    pub token: Token,
     pub name: Identifier,
     pub value: Rc<dyn Expression>,
 }
 
-impl Node for Let {}
+impl PartialEq for Let {
+    fn eq(&self, other: &Self) -> bool {
+        if self.name != other.name {
+            return false;
+        }
+
+        node_type_eq!(self.value, other.value)
+    }
+}
+
+impl Node for Let {
+    fn node_type(&self) -> NodeType {
+        NodeType::LetStatement
+    }
+}
 
 impl Statement for Let {}
 
 #[derive(Debug)]
 pub struct Return {
-    pub token: Token,
     pub value: Rc<dyn Expression>,
 }
 
+impl PartialEq for Return {
+    fn eq(&self, other: &Self) -> bool {
+        node_type_eq!(self.value, other.value)
+    }
+}
+
+impl Node for Return {
+    fn node_type(&self) -> NodeType {
+        NodeType::ReturnStatement
+    }
+}
+
 impl Statement for Return {}
 
-impl Node for Return {}
-
 #[derive(Debug)]
 pub struct ExpressionStatement {
-    // TODO: probably not needed
-    pub token: Token,
     pub expression: Rc<dyn Expression>,
 }
 
+impl PartialEq for ExpressionStatement {
+    fn eq(&self, other: &Self) -> bool {
+        let expr = &self.expression;
+        let other = &other.expression;
+
+        node_type_eq!(expr, other)
+    }
+}
+
+impl Node for ExpressionStatement {
+    fn node_type(&self) -> NodeType {
+        NodeType::ExpressionStatement
+    }
+}
+
 impl Statement for ExpressionStatement {}
 
-impl Node for ExpressionStatement {}
-
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Identifier {
     pub token_type: TokenType,
     pub value: String,
 }
 
-impl Node for Identifier {}
+impl Node for Identifier {
+    fn node_type(&self) -> NodeType {
+        NodeType::IdentifierExpression
+    }
+}
 
 impl Expression for Identifier {}
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct IntegerLiteral {
     pub value: i64,
 }
 
-impl Node for IntegerLiteral {}
+impl Node for IntegerLiteral {
+    fn node_type(&self) -> NodeType {
+        NodeType::IntegerLiteralExpression
+    }
+}
 
 impl Expression for IntegerLiteral {}
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum PrefixOperator {
     Minus,
     Bang,
@@ -105,11 +249,25 @@ pub struct Prefix {
     pub right: Rc<dyn Expression>,
 }
 
-impl Node for Prefix {}
+impl PartialEq for Prefix {
+    fn eq(&self, other: &Self) -> bool {
+        if self.operator != other.operator {
+            return false;
+        }
+        println!("Prefix PartialEq");
+        node_type_eq!(self.right, other.right)
+    }
+}
+
+impl Node for Prefix {
+    fn node_type(&self) -> NodeType {
+        NodeType::PrefixExpression
+    }
+}
 
 impl Expression for Prefix {}
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum InfixOperator {
     Plus,
     Minus,
@@ -168,13 +326,42 @@ pub struct Infix {
     pub right: Rc<dyn Expression>,
 }
 
-impl Node for Infix {}
+impl PartialEq for Infix {
+    fn eq(&self, other: &Self) -> bool {
+        self.operator == other.operator
+            && node_type_eq!(self.left, other.left)
+            && node_type_eq!(self.right, other.right)
+    }
+}
+
+impl Node for Infix {
+    fn node_type(&self) -> NodeType {
+        NodeType::InfixExpression
+    }
+}
 
 impl Expression for Infix {}
 
+#[derive(Debug, PartialEq, Eq)]
+pub struct Boolean {
+    pub value: bool,
+}
+
+impl Node for Boolean {
+    fn node_type(&self) -> NodeType {
+        NodeType::BooleanExpression
+    }
+}
+
+impl Expression for Boolean {}
+
 #[derive(Debug)]
 pub struct DummyExpression {}
 
-impl Node for DummyExpression {}
+impl Node for DummyExpression {
+    fn node_type(&self) -> NodeType {
+        NodeType::DummyExpression
+    }
+}
 
 impl Expression for DummyExpression {}

src/lexer.rs

@@ -158,45 +158,45 @@ mod tests {
                     10 == 10;
                     10 != 9;
                      "
-        .to_string();
+        .into();
 
         use Token::*;
 
         let tests = vec![
             Let,
-            Ident("five".to_string()),
+            Ident("five".into()),
             Assign,
             Int(5),
             Semicolon,
             Let,
-            Ident("ten".to_string()),
+            Ident("ten".into()),
             Assign,
             Int(10),
             Semicolon,
             Let,
-            Ident("add".to_string()),
+            Ident("add".into()),
             Assign,
             Function,
             Lparen,
-            Ident("x".to_string()),
+            Ident("x".into()),
             Comma,
-            Ident("y".to_string()),
+            Ident("y".into()),
             Rparen,
             Lbrace,
-            Ident("x".to_string()),
+            Ident("x".into()),
             Plus,
-            Ident("y".to_string()),
+            Ident("y".into()),
             Semicolon,
             Rbrace,
             Semicolon,
             Let,
-            Ident("result".to_string()),
+            Ident("result".into()),
             Assign,
-            Ident("add".to_string()),
+            Ident("add".into()),
             Lparen,
-            Ident("five".to_string()),
+            Ident("five".into()),
             Comma,
-            Ident("ten".to_string()),
+            Ident("ten".into()),
             Rparen,
             Semicolon,
             Bang,

src/parser.rs

@@ -2,8 +2,8 @@ use std::{fmt, rc::Rc};
 
 use crate::{
     ast::{
-        DummyExpression, Expression, ExpressionStatement, Identifier, Infix, InfixOperator,
-        IntegerLiteral, Let, Prefix, PrefixOperator, Program, Return, Statement,
+        Boolean, DummyExpression, Expression, ExpressionStatement, Identifier, Infix,
+        InfixOperator, IntegerLiteral, Let, Prefix, PrefixOperator, Program, Return, Statement,
     },
     lexer::Lexer,
     token::{self, Token, TokenType},
@@ -64,7 +64,7 @@ impl fmt::Display for Error {
                 "expected token `{expected}`, actual token: `{}`",
                 match actual {
                     Some(token) => format!("{token}"),
-                    None => "None".to_string(),
+                    None => "None".into(),
                 },
             ),
             NoPrefixParseFnFound(t) => write!(f, "no prefix parse function found for `{t}`"),
@@ -131,12 +131,6 @@ impl Parser {
     }
 
     fn parse_let_statement(&mut self) -> Option<Rc<dyn Statement>> {
-        let token = if let Some(token) = &self.cur_token {
-            token.clone()
-        } else {
-            return None;
-        };
-
         let value = self.expect_peek_ident()?;
 
         let name = Identifier {
@@ -148,35 +142,33 @@ impl Parser {
             return None;
         }
 
-        while !self.cur_token_is(TokenType::Semicolon) {
-            self.next();
-        }
-        let value = Rc::new(DummyExpression {});
+        self.next();
 
-        Some(Rc::new(Let { token, name, value }))
+        // TODO: maybe not unwrap
+        let value = self.parse_expression(Precedence::Lowest).unwrap();
+        self.next();
+
+        Some(Rc::new(Let { name, value }))
     }
 
     fn parse_return_statement(&mut self) -> Option<Rc<dyn Statement>> {
-        let token = self.cur_token.clone().unwrap();
+        self.next();
 
-        while !self.cur_token_is(TokenType::Semicolon) {
-            self.next();
-        }
-        let value = Rc::new(DummyExpression {});
+        // TODO: maybe not unwrap
+        let value = self.parse_expression(Precedence::Lowest).unwrap();
+        self.next();
 
-        Some(Rc::new(Return { token, value }))
+        Some(Rc::new(Return { value }))
     }
 
     fn parse_expression_statement(&mut self) -> Option<Rc<dyn Statement>> {
-        let token = self.cur_token.clone()?;
-
         let expression = self.parse_expression(Precedence::Lowest)?;
 
         if self.peek_token_is(TokenType::Semicolon) {
             self.next();
         }
 
-        Some(Rc::new(ExpressionStatement { token, expression }))
+        Some(Rc::new(ExpressionStatement { expression }))
     }
 
     fn parse_expression(&mut self, precedence: Precedence) -> Option<Rc<dyn Expression>> {
@@ -237,6 +229,12 @@ impl Parser {
         Rc::new(Prefix { operator, right })
     }
 
+    fn parse_boolean(&mut self) -> Rc<dyn Expression> {
+        Rc::new(Boolean {
+            value: self.cur_token_is(TokenType::True),
+        })
+    }
+
     fn parse_infix_expression(&mut self, left: Rc<dyn Expression>) -> Rc<dyn Expression> {
         let token = if let Some(token) = &self.cur_token {
             token
@@ -375,6 +373,8 @@ impl Parser {
             Bang => Some(Box::new(|parser| {
                 Self::parse_prefix_expression(parser, PrefixOperator::Bang)
             })),
+            True => Some(Box::new(Self::parse_boolean)),
+            False => Some(Box::new(Self::parse_boolean)),
             _ => None,
         }
     }
@@ -417,9 +417,12 @@ mod tests {
     use std::rc::Rc;
 
     use crate::{
-        ast::{InfixOperator, PrefixOperator, Statement},
+        ast::{
+            Boolean, ExpressionStatement, Identifier, Infix, InfixOperator, IntegerLiteral, Let,
+            Prefix, PrefixOperator, Program, Return, Statement,
+        },
         lexer::Lexer,
-        token::Token,
+        token::{Token, TokenType},
     };
 
     use super::Parser;
@@ -430,7 +433,7 @@ mod tests {
                      let y = 10;\
                      let foobar = 838383;\
                      "
-        .to_string();
+        .into();
 
         let lexer = Lexer::new(source);
 
@@ -439,14 +442,34 @@ mod tests {
         let program = parser.parse().unwrap();
         check_parser_errors(parser);
 
-        assert_eq!(program.statements.len(), 3);
-
-        let expected_identifiers = vec!["x", "y", "foobar"];
-        let mut statements_iter = program.statements.iter();
-        for tt in expected_identifiers {
-            let statement = statements_iter.next().unwrap();
-            test_let_statement(statement.clone(), tt);
-        }
+        assert_eq!(
+            program,
+            Program {
+                statements: vec![
+                    Rc::new(Let {
+                        name: Identifier {
+                            token_type: TokenType::Let,
+                            value: "x".into()
+                        },
+                        value: Rc::new(IntegerLiteral { value: 5 })
+                    }),
+                    Rc::new(Let {
+                        name: Identifier {
+                            token_type: TokenType::Let,
+                            value: "y".into()
+                        },
+                        value: Rc::new(IntegerLiteral { value: 10 })
+                    }),
+                    Rc::new(Let {
+                        name: Identifier {
+                            token_type: TokenType::Let,
+                            value: "foobar".into()
+                        },
+                        value: Rc::new(IntegerLiteral { value: 838383 })
+                    })
+                ]
+            }
+        );
     }
 
     #[test]
@@ -455,7 +478,7 @@ mod tests {
                      return 10;\
                      return 838383;\
                      "
-        .to_string();
+        .into();
 
         let lexer = Lexer::new(source);
 
@@ -464,19 +487,27 @@ mod tests {
         let program = parser.parse().unwrap();
         check_parser_errors(parser);
 
-        assert_eq!(program.statements.len(), 3);
-
-        for stmt in program.statements {
-            assert_eq!(
-                format!("{stmt:?}"),
-                "Return { token: Return, value: DummyExpression }"
-            )
-        }
+        assert_eq!(
+            program,
+            Program {
+                statements: vec![
+                    Rc::new(Return {
+                        value: Rc::new(IntegerLiteral { value: 5 })
+                    }),
+                    Rc::new(Return {
+                        value: Rc::new(IntegerLiteral { value: 10 })
+                    }),
+                    Rc::new(Return {
+                        value: Rc::new(IntegerLiteral { value: 838383 })
+                    })
+                ]
+            }
+        );
     }
 
     #[test]
     fn identifier_expression() {
-        let source = "foobar;".to_owned();
+        let source = "foobar;".into();
 
         let lexer = Lexer::new(source);
 
@@ -485,17 +516,42 @@ mod tests {
         let program = parser.parse().unwrap();
         check_parser_errors(parser);
 
-        let expected_identifiers = vec!["foobar"];
-        let mut statements_iter = program.statements.iter();
-        for tt in expected_identifiers {
-            let statement = statements_iter.next().unwrap();
-            test_identifier_expression(statement.clone(), tt);
-        }
+        assert_eq!(
+            program,
+            Program {
+                statements: vec![Rc::new(ExpressionStatement {
+                    expression: Rc::new(Identifier {
+                        token_type: TokenType::Ident,
+                        value: "foobar".into()
+                    })
+                })]
+            }
+        );
     }
 
     #[test]
     fn integer_literal_expression() {
-        let source = "6;".to_owned();
+        let source = "6;".into();
+
+        let lexer = Lexer::new(source);
+
+        let mut parser = Parser::new(lexer);
+
+        let program = parser.parse().unwrap();
+        check_parser_errors(parser);
+        assert_eq!(
+            program,
+            Program {
+                statements: vec![Rc::new(ExpressionStatement {
+                    expression: Rc::new(IntegerLiteral { value: 6 })
+                })]
+            }
+        );
+    }
+
+    #[test]
+    fn bool_expression() {
+        let source = "true; false".into();
 
         let lexer = Lexer::new(source);
 
@@ -504,12 +560,19 @@ mod tests {
         let program = parser.parse().unwrap();
         check_parser_errors(parser);
 
-        let expected_integers = vec![6];
-        let mut statements_iter = program.statements.iter();
-        for tt in expected_integers {
-            let statement = statements_iter.next().unwrap();
-            test_integer_literal_expression(statement.clone(), tt);
-        }
+        assert_eq!(
+            program,
+            Program {
+                statements: vec![
+                    Rc::new(ExpressionStatement {
+                        expression: Rc::new(Boolean { value: true })
+                    }),
+                    Rc::new(ExpressionStatement {
+                        expression: Rc::new(Boolean { value: false })
+                    })
+                ]
+            }
+        );
     }
 
     #[test]
@@ -523,13 +586,13 @@ mod tests {
 
         let tests = vec![
             Test {
-                input: "!15".to_owned(),
+                input: "!15".into(),
                 token: Token::Bang,
                 operator: PrefixOperator::Bang,
                 value: 15,
             },
             Test {
-                input: "-15".to_owned(),
+                input: "-15".into(),
                 token: Token::Minus,
                 operator: PrefixOperator::Minus,
                 value: 15,
@@ -544,13 +607,16 @@ mod tests {
             let program = parser.parse().unwrap();
             check_parser_errors(parser);
 
-            assert_eq!(program.statements.len(), 1);
-
-            test_prefix_expression(
-                program.statements.first().unwrap().clone(),
-                test.token,
-                test.operator,
-                test.value,
+            assert_eq!(
+                program,
+                Program {
+                    statements: vec![Rc::new(ExpressionStatement {
+                        expression: Rc::new(Prefix {
+                            operator: test.operator,
+                            right: Rc::new(IntegerLiteral { value: test.value })
+                        })
+                    })]
+                }
             );
         }
     }
@@ -623,24 +689,25 @@ mod tests {
             let program = parser.parse().unwrap();
             check_parser_errors(parser);
 
-            assert_eq!(program.statements.len(), 1);
-
-            test_infix_expression(
-                program.statements.first().unwrap().clone(),
-                test.left_value,
-                test.operator,
-                test.right_value,
+            assert_eq!(
+                program,
+                Program {
+                    statements: vec![Rc::new(ExpressionStatement {
+                        expression: Rc::new(Infix {
+                            operator: test.operator,
+                            left: Rc::new(IntegerLiteral {
+                                value: test.left_value
+                            }),
+                            right: Rc::new(IntegerLiteral {
+                                value: test.right_value
+                            })
+                        })
+                    })]
+                }
             );
         }
     }
 
-    fn test_let_statement(stmt: Rc<dyn Statement>, name: &str) {
-        assert_eq!(
-            format!("{stmt:?}"),
-            format!("Let {{ token: Let, name: Identifier {{ token_type: Let, value: \"{name}\" }}, value: DummyExpression }}"),
-        );
-    }
-
     fn check_parser_errors(parser: Parser) {
         if parser.errors().len() == 0 {
             return;
@@ -654,46 +721,4 @@ mod tests {
 
         panic!("{err}");
     }
-
-    fn test_identifier_expression(stmt: Rc<dyn Statement>, name: &str) {
-        assert_eq!(
-            format!("{stmt:?}"),
-            format!(
-                "ExpressionStatement {{ token: Ident(\"{name}\"), expression: Identifier {{ token_type: Ident, value: \"{name}\" }} }}"
-            ),
-        );
-    }
-
-    fn test_integer_literal_expression(stmt: Rc<dyn Statement>, num: i64) {
-        assert_eq!(
-            format!("{stmt:?}"),
-            format!(
-                "ExpressionStatement {{ token: Int({num}), expression: IntegerLiteral {{ value: {num} }} }}"
-            ),
-        );
-    }
-
-    fn test_prefix_expression(
-        stmt: Rc<dyn Statement>,
-        token: Token,
-        operator: PrefixOperator,
-        num: i64,
-    ) {
-        assert_eq!(
-            format!("{stmt:?}"),
-            format!("ExpressionStatement {{ token: {token:?}, expression: Prefix {{ operator: {operator:?}, right: IntegerLiteral {{ value: {num} }} }} }}"),
-        );
-    }
-
-    fn test_infix_expression(
-        stmt: Rc<dyn Statement>,
-        left: i64,
-        operator: InfixOperator,
-        right: i64,
-    ) {
-        assert_eq!(
-            format!("{stmt:?}"),
-            format!("ExpressionStatement {{ token: Int({left}), expression: Infix {{ operator: {operator:?}, left: IntegerLiteral {{ value: {left} }}, right: IntegerLiteral {{ value: {right} }} }} }}"),
-        );
-    }
 }

src/token.rs

@@ -1,6 +1,6 @@
 use std::fmt::Display;
 
-#[derive(Debug, PartialEq, Clone)]
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub enum Token {
     Illegal,
     EOF,
@@ -154,7 +154,7 @@ impl Token {
             "if" => If,
             "else" => Else,
             "return" => Return,
-            ident => Ident(ident.to_string()),
+            ident => Ident(ident.into()),
         }
     }
 }