Implement lexing and parsing for classes.

dmc-lib/src/ast/class.rs

@@ -0,0 +1,27 @@
+use crate::ast::field::Field;
+use crate::ast::function::Function;
+use crate::source_range::SourceRange;
+use std::rc::Rc;
+
+pub struct Class {
+    declared_name: Rc<str>,
+    declared_name_source_range: SourceRange,
+    fields: Vec<Field>,
+    functions: Vec<Function>,
+}
+
+impl Class {
+    pub fn new(
+        declared_name: &str,
+        declared_name_source_range: SourceRange,
+        fields: Vec<Field>,
+        functions: Vec<Function>,
+    ) -> Self {
+        Class {
+            declared_name: declared_name.into(),
+            declared_name_source_range,
+            fields,
+            functions,
+        }
+    }
+}

dmc-lib/src/ast/field.rs

@@ -0,0 +1,33 @@
+use crate::ast::expression::Expression;
+use crate::ast::type_use::TypeUse;
+use crate::source_range::SourceRange;
+use std::rc::Rc;
+
+pub struct Field {
+    declared_name: Rc<str>,
+    declared_name_source_range: SourceRange,
+    is_public: bool,
+    is_mut: bool,
+    declared_type: Option<Box<TypeUse>>,
+    initializer: Option<Box<Expression>>,
+}
+
+impl Field {
+    pub fn new(
+        declared_name: &str,
+        declared_name_source_range: SourceRange,
+        is_public: bool,
+        is_mut: bool,
+        declared_type: Option<TypeUse>,
+        initializer: Option<Expression>,
+    ) -> Self {
+        Self {
+            declared_name: declared_name.into(),
+            declared_name_source_range,
+            is_public,
+            is_mut,
+            declared_type: declared_type.map(Box::new),
+            initializer: initializer.map(Box::new),
+        }
+    }
+}

dmc-lib/src/ast/function.rs

@@ -16,6 +16,7 @@ use std::rc::Rc;
 pub struct Function {
     declared_name: String,
     declared_name_source_range: SourceRange,
+    is_public: bool,
     parameters: Vec<Parameter>,
     return_type: Option<TypeUse>,
     statements: Vec<Statement>,
@@ -26,6 +27,7 @@ impl Function {
     pub fn new(
         declared_name: &str,
         declared_name_source_range: SourceRange,
+        is_public: bool,
         parameters: Vec<Parameter>,
         return_type: Option<TypeUse>,
         statements: Vec<Statement>,
@@ -33,6 +35,7 @@ impl Function {
         Self {
             declared_name: declared_name.to_string(),
             declared_name_source_range,
+            is_public,
             parameters,
             return_type,
             statements,

dmc-lib/src/ast/mod.rs

@@ -1,10 +1,12 @@
 pub mod add_expression;
 pub mod call;
+pub mod class;
 pub mod compilation_unit;
 pub mod double_literal;
 pub mod expression;
 pub mod expression_statement;
 pub mod extern_function;
+pub mod field;
 pub mod fqn;
 pub mod function;
 pub mod identifier;

dmc-lib/src/ast/module_level_declaration.rs

@@ -1,3 +1,4 @@
+use crate::ast::class::Class;
 use crate::ast::extern_function::ExternFunction;
 use crate::ast::function::Function;
 use crate::diagnostic::Diagnostic;
@@ -6,6 +7,7 @@ use crate::symbol_table::SymbolTable;
 pub enum ModuleLevelDeclaration {
     Function(Function),
     ExternFunction(ExternFunction),
+    Class(Class),
 }
 
 impl ModuleLevelDeclaration {
@@ -20,6 +22,9 @@ impl ModuleLevelDeclaration {
             ModuleLevelDeclaration::ExternFunction(extern_function) => {
                 extern_function.gather_declared_names(symbol_table)
             }
+            ModuleLevelDeclaration::Class(class) => {
+                todo!()
+            }
         }
     }
 
@@ -29,6 +34,9 @@ impl ModuleLevelDeclaration {
             ModuleLevelDeclaration::ExternFunction(extern_function) => {
                 extern_function.check_name_usages(symbol_table)
             }
+            ModuleLevelDeclaration::Class(class) => {
+                todo!()
+            }
         }
     }
 
@@ -38,6 +46,9 @@ impl ModuleLevelDeclaration {
             ModuleLevelDeclaration::ExternFunction(extern_function) => {
                 extern_function.type_check(symbol_table)
             }
+            ModuleLevelDeclaration::Class(class) => {
+                todo!()
+            }
         }
     }
 }

dmc-lib/src/diagnostic.rs

@@ -3,6 +3,8 @@ pub struct Diagnostic {
     message: String,
     start: usize,
     end: usize,
+    reporter_file: Option<&'static str>,
+    reporter_line: Option<u32>,
 }
 
 impl Diagnostic {
@@ -11,6 +13,8 @@ impl Diagnostic {
             message: message.into(),
             start,
             end,
+            reporter_line: None,
+            reporter_file: None,
         }
     }
 
@@ -25,4 +29,14 @@ impl Diagnostic {
     pub fn end(&self) -> usize {
         self.end
     }
+
+    pub fn with_reporter(&self, file: &'static str, line: u32) -> Self {
+        Self {
+            message: self.message.clone(),
+            start: self.start,
+            end: self.end,
+            reporter_file: Some(file),
+            reporter_line: Some(line),
+        }
+    }
 }

dmc-lib/src/lexer.rs

@@ -54,6 +54,8 @@ impl<'a> Lexer<'a> {
             Token::new(self.position, self.position + 1, TokenKind::Comma)
         } else if chunk.starts_with(":") {
             Token::new(self.position, self.position + 1, TokenKind::Colon)
+        } else if chunk.starts_with(".") {
+            Token::new(self.position, self.position + 1, TokenKind::Dot)
         } else {
             // more than one char token
             if chunk.starts_with(|c: char| c.is_ascii_digit()) {
@@ -118,11 +120,22 @@ impl<'a> Lexer<'a> {
                         break;
                     }
                 }
+
+                if prefix.len() == 0 {
+                    return Some(Err(LexerError::new(LexerErrorKind::UnrecognizedCharacter(
+                        chunk.chars().next().unwrap(),
+                    ))));
+                }
+
                 let token_kind = match prefix.as_str() {
                     "fn" => TokenKind::Fn,
                     "end" => TokenKind::End,
                     "let" => TokenKind::Let,
                     "extern" => TokenKind::Extern,
+                    "class" => TokenKind::Class,
+                    "self" => TokenKind::SelfKw,
+                    "pub" => TokenKind::Public,
+                    "mut" => TokenKind::Mut,
                     _ => TokenKind::Identifier,
                 };
                 Token::new(self.position, self.position + prefix.len(), token_kind)
@@ -151,6 +164,7 @@ impl LexerError {
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub enum LexerErrorKind {
     UnterminatedString,
+    UnrecognizedCharacter(char),
 }
 
 #[cfg(test)]
@@ -239,4 +253,31 @@ mod tests {
         assert_next(&mut lexer, TokenKind::RightParentheses, 1);
         assert!(lexer.next().is_none());
     }
+
+    #[test]
+    fn class_with_fields_smoke_test() {
+        let mut lexer = Lexer::new(
+            "
+            class Foo
+                pub bar: Int
+                mut baz: String
+                car = 42                
+
+                fn new(bar: Int, baz: String)
+                    self.bar = bar
+                    self.baz = baz
+                end
+            end
+            ",
+        );
+        while let Some(result) = lexer.next() {
+            match result {
+                Ok(_) => {}
+                Err(lexer_error) => {
+                    panic!("{:?}", lexer_error);
+                }
+            }
+        }
+        assert!(lexer.next().is_none());
+    }
 }

dmc-lib/src/parser.rs

@@ -1,10 +1,12 @@
 use crate::ast::add_expression::AddExpression;
 use crate::ast::call::Call;
+use crate::ast::class::Class;
 use crate::ast::compilation_unit::CompilationUnit;
 use crate::ast::double_literal::DoubleLiteral;
 use crate::ast::expression::Expression;
 use crate::ast::expression_statement::ExpressionStatement;
 use crate::ast::extern_function::ExternFunction;
+use crate::ast::field::Field;
 use crate::ast::function::Function;
 use crate::ast::identifier::Identifier;
 use crate::ast::integer_literal::IntegerLiteral;
@@ -33,6 +35,21 @@ pub fn parse_expression(input: &str) -> Result<Expression, Vec<Diagnostic>> {
     parser.expression()
 }
 
+macro_rules! matches_expression_first {
+    ( $token_kind : expr ) => {
+        matches!(
+            $token_kind,
+            TokenKind::IntegerLiteral
+                | TokenKind::DoubleLiteral
+                | TokenKind::LongLiteral
+                | TokenKind::String
+                | TokenKind::Minus
+                | TokenKind::SelfKw
+                | TokenKind::Identifier
+        )
+    };
+}
+
 struct Parser<'a> {
     input: &'a str,
     lexer: Lexer<'a>,
@@ -113,22 +130,28 @@ impl<'a> Parser<'a> {
 
     fn expect_advance(&mut self, token_kind: TokenKind) -> Result<Token, Vec<Diagnostic>> {
         match self.current.take() {
-            None => Err(vec![Diagnostic::new(
+            None => Err(vec![
+                Diagnostic::new(
                     &format!("Expected {:?} but found end-of-input.", token_kind),
                     self.input.len(),
                     self.input.len(),
-            )]),
+                )
+                .with_reporter(file!(), line!()),
+            ]),
             Some(token) => {
                 if token.kind() == token_kind {
                     self.advance();
                     Ok(token)
                 } else {
                     self.advance_until(&[token_kind]);
-                    Err(vec![Diagnostic::new(
+                    Err(vec![
+                        Diagnostic::new(
                             &format!("Expected {:?} but found {:?}", token_kind, token.kind()),
                             token.start(),
                             token.end(),
-                    )])
+                        )
+                        .with_reporter(file!(), line!()),
+                    ])
                 }
             }
         }
@@ -172,7 +195,7 @@ impl<'a> Parser<'a> {
         while self.current.is_some() {
             let current = self.get_current();
             match current.kind() {
-                TokenKind::Fn | TokenKind::Extern => {
+                TokenKind::Fn | TokenKind::Extern | TokenKind::Class => {
                     let declaration_result = self.module_level_declaration();
                     match declaration_result {
                         Ok(declaration) => declarations.push(declaration),
@@ -184,8 +207,8 @@ impl<'a> Parser<'a> {
                 _ => {
                     diagnostics.push(Diagnostic::new(
                         &format!(
-                            "Expected any of: {:?}; found {:?}",
+                            "Expected any of {:?}; found {:?}",
-                            [TokenKind::Fn, TokenKind::Extern],
+                            [TokenKind::Fn, TokenKind::Extern, TokenKind::Class],
                             current.kind()
                         ),
                         current.start(),
@@ -221,11 +244,22 @@ impl<'a> Parser<'a> {
                     Err(extern_function_diagnostics) => Err(extern_function_diagnostics),
                 }
             }
+            TokenKind::Class => match self.class() {
+                Ok(class) => Ok(ModuleLevelDeclaration::Class(class)),
+                Err(class_diagnostics) => Err(class_diagnostics),
+            },
             _ => unreachable!(),
         }
     }
 
     fn function(&mut self) -> Result<Function, Vec<Diagnostic>> {
+        let is_public = if self.current.is_some() && self.peek_current(TokenKind::Public) {
+            self.advance(); // pub
+            true
+        } else {
+            false
+        };
+
         self.expect_advance(TokenKind::Fn)?;
         let identifier_token = self.expect_advance(TokenKind::Identifier)?;
 
@@ -273,6 +307,7 @@ impl<'a> Parser<'a> {
             Ok(Function::new(
                 self.token_text(&identifier_token),
                 SourceRange::new(identifier_token.start(), identifier_token.end()),
+                is_public,
                 parameters,
                 return_type,
                 statements,
@@ -323,6 +358,46 @@ impl<'a> Parser<'a> {
         }
     }
 
+    fn class(&mut self) -> Result<Class, Vec<Diagnostic>> {
+        self.expect_advance(TokenKind::Class)?;
+        let identifier_token = self.expect_advance(TokenKind::Identifier)?;
+        let mut fields = vec![];
+        let mut functions = vec![];
+
+        let mut diagnostics = vec![];
+
+        while self.current.is_some() && !self.peek_current(TokenKind::End) {
+            match self.get_current().kind() {
+                TokenKind::Public => match self.public_class_member(&mut fields, &mut functions) {
+                    Ok(_) => {}
+                    Err(mut member_diagnostics) => diagnostics.append(&mut member_diagnostics),
+                },
+                TokenKind::Mut | TokenKind::Identifier => match self.field() {
+                    Ok(field) => fields.push(field),
+                    Err(mut field_diagnostics) => diagnostics.append(&mut field_diagnostics),
+                },
+                TokenKind::Fn => match self.function() {
+                    Ok(function) => functions.push(function),
+                    Err(mut function_diagnostics) => diagnostics.append(&mut function_diagnostics),
+                },
+                _ => unreachable!(),
+            }
+        }
+
+        self.expect_advance(TokenKind::End)?;
+
+        if diagnostics.is_empty() {
+            Ok(Class::new(
+                self.token_text(&identifier_token),
+                SourceRange::new(identifier_token.start(), identifier_token.end()),
+                fields,
+                functions,
+            ))
+        } else {
+            Err(diagnostics)
+        }
+    }
+
     fn parameter_list(&mut self) -> Result<Vec<Parameter>, Vec<Diagnostic>> {
         let mut parameters = vec![];
         let mut diagnostics = vec![];
@@ -371,6 +446,86 @@ impl<'a> Parser<'a> {
         ))
     }
 
+    fn public_class_member(
+        &mut self,
+        fields: &mut Vec<Field>,
+        functions: &mut Vec<Function>,
+    ) -> Result<(), Vec<Diagnostic>> {
+        if self.lookahead.is_some() {
+            if matches!(
+                self.lookahead.as_ref().unwrap().kind(),
+                TokenKind::Mut | TokenKind::Identifier
+            ) {
+                fields.push(self.field()?);
+            } else if matches!(self.lookahead.as_ref().unwrap().kind(), TokenKind::Fn) {
+                functions.push(self.function()?);
+            } else {
+                let lookahead = self.lookahead.as_ref().unwrap();
+                return Err(vec![Diagnostic::new(
+                    &format!(
+                        "Expected any of {:?}; found {:?}",
+                        [TokenKind::Mut, TokenKind::Identifier, TokenKind::Fn],
+                        lookahead.kind()
+                    ),
+                    lookahead.start(),
+                    lookahead.end(),
+                )]);
+            }
+            Ok(())
+        } else {
+            let current = self.current.as_ref().unwrap();
+            Err(vec![Diagnostic::new(
+                &format!(
+                    "Expected any of {:?}; found end-of-input.",
+                    [TokenKind::Mut, TokenKind::Identifier, TokenKind::Fn]
+                ),
+                current.end(),
+                current.end(),
+            )])
+        }
+    }
+
+    fn field(&mut self) -> Result<Field, Vec<Diagnostic>> {
+        let is_public = if self.current.is_some() && self.peek_current(TokenKind::Public) {
+            self.advance();
+            true
+        } else {
+            false
+        };
+
+        let is_mut = if self.current.is_some() && self.peek_current(TokenKind::Mut) {
+            self.advance();
+            true
+        } else {
+            false
+        };
+
+        let identifier = self.expect_advance(TokenKind::Identifier)?;
+
+        let declared_type = if self.current.is_some() && self.peek_current(TokenKind::Colon) {
+            self.advance(); // colon
+            Some(self.type_use()?)
+        } else {
+            None
+        };
+
+        let initializer = if self.current.is_some() && self.peek_current(TokenKind::Equals) {
+            self.advance(); // equals
+            Some(self.expression()?)
+        } else {
+            None
+        };
+
+        Ok(Field::new(
+            self.token_text(&identifier),
+            SourceRange::new(identifier.start(), identifier.end()),
+            is_public,
+            is_mut,
+            declared_type,
+            initializer,
+        ))
+    }
+
     fn statement(&mut self) -> Result<Statement, Vec<Diagnostic>> {
         let current = self.get_current();
         match current.kind() {
@@ -517,13 +672,7 @@ impl<'a> Parser<'a> {
         self.expect_advance(TokenKind::LeftParentheses)?;
         let mut arguments = vec![];
         if let Some(current) = &self.current {
-            if matches!(
+            if matches_expression_first!(current.kind()) {
-                current.kind(),
-                TokenKind::IntegerLiteral
-                    | TokenKind::DoubleLiteral
-                    | TokenKind::String
-                    | TokenKind::Identifier
-            ) {
                 arguments.append(&mut self.expression_list()?);
             }
         }
@@ -628,6 +777,57 @@ mod smoke_tests {
     fn minus_negative_number() {
         smoke_test("fn main() -> Int 1 - -1 end");
     }
+
+    #[test]
+    fn empty_class() {
+        smoke_test("class Foo end");
+    }
+
+    #[test]
+    fn class_with_pub_member() {
+        smoke_test("class Foo pub bar end");
+    }
+
+    #[test]
+    fn class_with_mut_member() {
+        smoke_test("class Foo mut bar end");
+    }
+
+    #[test]
+    fn class_with_nothing_member() {
+        smoke_test("class Foo bar end");
+    }
+
+    #[test]
+    fn class_with_member_type_use() {
+        smoke_test("class Foo bar: Int end");
+    }
+
+    #[test]
+    fn class_with_member_init() {
+        smoke_test("class Foo bar = 42 end");
+    }
+
+    #[test]
+    fn class_with_member_type_use_and_init() {
+        smoke_test("class Foo bar: Int = 42 end");
+    }
+
+    #[test]
+    fn class_with_member_all() {
+        smoke_test("class Foo pub mut bar: Bar = Baz() end");
+    }
+
+    #[test]
+    fn class_with_pub_fn() {
+        smoke_test(
+            "
+            class Greeter
+                pub fn greet() end
+            end
+            ",
+        );
+    }
 }
 
 #[cfg(test)]

dmc-lib/src/token.rs

@@ -42,4 +42,9 @@ pub enum TokenKind {
     RightArrow,
     Plus,
     Minus,
+    Class,
+    Dot,
+    SelfKw,
+    Public,
+    Mut,
 }