Started writing new expression parser (It does not work right now)

src/ast.rs

@@ -6,8 +6,8 @@ use std::collections::HashMap;
 #[derive(Debug, Clone)]
 pub struct Function {
     pub name: String,
-    pub statements: Vec<Statement>,
+    pub statement: Statement,
-    pub n_args: u64,
+    pub args: Vec<String>,
     assembly: Option<String>,
 }
 
@@ -19,6 +19,27 @@ pub enum Statement {
     Scope(Vec<Statement>),
 }
 
+#[derive(Debug, Clone)]
+pub enum Expression {
+    Literal(Literal),
+    Variable(String),
+    Unary(Unary, Box<Expression>),
+    Grouping(Box<Expression>),
+    Binary(BinOp, Box<Expression>, Box<Expression>),
+}
+
+#[derive(Debug, Clone)]
+pub enum Unary {
+    PointerTo,
+    ValueFrom,
+}
+
+#[derive(Debug, Clone)]
+pub enum BinOp {
+    Plus,
+    Minus,
+}
+
 #[derive(Debug, Clone)]
 pub enum ValueNode {
     Literal(Literal),
@@ -48,11 +69,11 @@ pub trait Node {
 }
 
 impl Function {
-    pub fn new(name: String, n_args: u64, statements: Vec<Statement>) -> Function {
+    pub fn new(name: String, args: Vec<String>, statement: Statement) -> Function {
         Function {
             name,
-            statements,
+            statement,
-            n_args,
+            args,
             assembly: None,
         }
     }
@@ -78,8 +99,8 @@ fn get_default_functions() -> HashMap<String, Function> {
         "out".to_string(),
         Function {
             name: "out".to_string(),
-            statements: vec![],
+            statement: Statement::FunctionCall("".to_string(), vec![]),
-            n_args: 1,
+            args: vec!["value".to_string()],
             assembly: Some(
                 "
 out:
@@ -118,8 +139,8 @@ F-OUT   JMP           0xFF"
         "exit".to_string(),
         Function {
             name: "exit".to_string(),
-            statements: vec![],
+            statement: Statement::FunctionCall("".to_string(), vec![]),
-            n_args: 0,
+            args: vec![],
             assembly: Some(
                 "
 exit:
@@ -136,9 +157,25 @@ impl Node for Function {
     fn to_assembly(&self, state: &mut AssemblerState) -> String {
         match &self.assembly {
             Some(v) => v.to_string(),
-            None => format!(
+            None => {
-                "{}:
+                let name = &self.name;
-{}
+
+                let mut pop_argument_assembly = "ROM-OUT FLAGS-IN 0x80".to_string();
+
+                for argument in &self.args {
+                    state.variables.push(argument.to_string());
+                    pop_argument_assembly += "
+SE-OUT  A-IN  0xFF
+ROM-OUT B-IN  0x01
+ALU-OUT SE-IN 0xFF
+"
+                }
+
+                let statement_assembly = self.statement.to_assembly(state);
+                format!(
+                    "{name}:
+{statement_assembly}
+{pop_argument_assembly}
 ;
 ; Pop the return address of the stack
 ;
@@ -154,15 +191,8 @@ ROM-OUT FLAGS-IN      0x00 ; Add mode
 
 F-OUT   JMP           0xFF
 ",
-                self.name,
+                )
-                {
-                    self.statements
-                        .iter()
-                        .map(|x| x.to_assembly(state))
-                        .collect::<Vec<String>>()
-                        .join("\n")
             }
-            ),
         }
     }
 }
@@ -171,15 +201,7 @@ impl Node for Statement {
     fn to_assembly(&self, state: &mut AssemblerState) -> String {
         match self {
             Statement::Scope(statements) => {
-                let init_assembly = "
+                let dropped_length = state.variables.len();
-ROM-OUT FLAGS-IN 0x00
-SE-OUT  A-IN     0xFF
-ROM-OUT B-IN     0x01
-ALU-OUT SE-IN    0xFF
-"
-                .to_string();
-
-                state.variables.push("start scope".to_string());
 
                 let statement_assembly = statements
                     .iter()
@@ -187,33 +209,20 @@ ALU-OUT SE-IN    0xFF
                     .collect::<Vec<String>>()
                     .join("\n");
 
-                let mut stop_assembly = "".to_string();
+                while state.variables.len() > dropped_length {
-
-                while state.variables.contains(&"start scope".to_string()) {
-                    stop_assembly += &format!(
-                        "
-ROM-OUT FLAGS-IN 0x80
-SE-OUT  A-IN     0xFF
-ROM-OUT B-IN     0x01
-ALU-OUT SE-IN    0xFF
-ROM-OUT FLAGS-IN 0x00"
-                    );
                     state.variables.pop();
                 }
+                dbg!(&state.variables);
 
-                format!(
+                statement_assembly
-                    "{init_assembly}
-{statement_assembly}
-{stop_assembly}"
-                )
             }
             Statement::FunctionCall(name, arguments) => {
                 if !state.functions.contains_key(name) {
                     todo!()
                 }
 
-
                 state.variables.push(name.to_owned());
+                dbg!(&state.variables);
                 let argument_assembly: String = arguments
                     .into_iter()
                     .map(|x| x.to_assembly(state))
@@ -226,7 +235,7 @@ ROM-OUT FLAGS-IN 0x00"
                     .map(char::from)
                     .collect();
 
-                for _ in 0..state.functions.get(name).unwrap().n_args {
+                for _ in &state.functions.get(name).unwrap().args {
                     state.variables.pop();
                 }
 
@@ -316,6 +325,7 @@ impl Node for ValueNode {
                     - state.variables.iter().position(|x| x == name).unwrap()
                     - 1;
 
+                dbg!(&state.variables);
                 state.variables.push(name.to_owned());
 
                 format!(

src/main.rs

@@ -1,17 +1,28 @@
+use crate::tokeniser::Token;
+
 mod ast;
 mod parse;
 mod tokeniser;
 
 fn main() {
-    let filename = "test.plonkus";
+    // let filename: &str = &std::env::args().collect::<Vec<String>>()[1];
 
-    let contents = std::fs::read_to_string(filename).expect(&format!("No file named {}", filename));
+    // let contents = std::fs::read_to_string(filename).expect(&format!("No file named {}", filename));
 
-    let tokens = tokeniser::tokenise(contents);
+    // let tokens = tokeniser::tokenise(contents);
 
-    let functions = dbg!(parse::ast(tokens));
+    // let functions = dbg!(parse::ast(tokens));
 
-    let assembly = ast::to_assembly(functions);
+    // let assembly = ast::to_assembly(functions);
 
-    println!("{}", assembly);
+    // println!("{}", assembly);
+
+    let mut i: usize = 0;
+    let tokens: Vec<tokeniser::Token> = vec![
+        Token::OpenParanthesis,
+        Token::Star,
+        Token::Number("2".to_string()),
+        Token::CloseParanthesis,
+    ];
+    dbg!(parse::parse_expression(&tokens, &mut i));
 }

src/parse.rs

@@ -66,77 +66,143 @@ fn parse_math(tokens: &Vec<Token>) -> ValueNode {
     };
 }
 
-fn parse_statements(tokens: &Vec<Token>, starting_i: usize) -> (Vec<Statement>, usize) {
+fn parse_basic(tokens: &Vec<Token>, i: &mut usize) -> Expression {
-    let mut i = starting_i;
+    let literal = match &tokens[*i] {
+        Token::Identifier(identifier) => Expression::Variable(identifier.to_owned()),
+        Token::Number(number) => Expression::Literal(Literal::Int(number.parse::<i64>().unwrap())),
+        _ => todo!(),
+    };
+    *i += 1;
+    literal
+}
+
+fn parse_grouping(tokens: &Vec<Token>, i: &mut usize) -> Expression {
+    match &tokens[*i] {
+        Token::OpenParanthesis => {
+            *i += 1;
+        }
+        _ => todo!(),
+    };
+
+    let inner_expression = parse_expression(tokens, i);
+
+    match &tokens[*i] {
+        Token::CloseParanthesis => {}
+        _ => todo!(),
+    };
+
+    inner_expression
+}
+
+// TODO: replace parse_math with this recursive function
+pub fn parse_expression(tokens: &Vec<Token>, i: &mut usize) -> Expression {
+    #[derive(Debug)]
+    enum OpExpr {
+        Expression(Expression),
+        BinOp(BinOp),
+        Unary(Unary),
+    }
+
+    let mut in_expressions_and_operators: Vec<OpExpr> = Vec::new();
+
+    loop {
+        in_expressions_and_operators.push(match &tokens[*i] {
+            Token::OpenParanthesis => OpExpr::Expression(parse_grouping(tokens, i)),
+            Token::Plus => {
+                *i += 1;
+                OpExpr::BinOp(BinOp::Plus)
+            }
+            Token::Minus => {
+                *i += 1;
+                OpExpr::BinOp(BinOp::Minus)
+            }
+            Token::Ampersand => {
+                *i += 1;
+                OpExpr::Unary(Unary::ValueFrom)
+            }
+            Token::Star => {
+                *i += 1;
+                OpExpr::Unary(Unary::PointerTo)
+            }
+            Token::Number(_) => OpExpr::Expression(parse_basic(tokens, i)),
+            _other => break,
+        });
+    }
+    dbg!(in_expressions_and_operators);
+    Expression::Variable("a".to_string())
+}
+
+fn parse_statements(tokens: &Vec<Token>, i: &mut usize) -> Vec<Statement> {
+    dbg!(&i);
     let mut statements = Vec::new();
-    while i < tokens.len() {
+    while *i < tokens.len() {
-        statements.push(match &tokens[i] {
+        statements.push(match &tokens[*i] {
             Token::OpenSquiglyBracket => {
-                let (statements, added_to_i) = parse_statements(tokens, i + 1);
+                *i += 1;
-                i = added_to_i + 1;
+                let statements = parse_statements(tokens, i);
                 Statement::Scope(statements)
             }
             Token::Keyword(Keyword::Let) => {
-                i += 1;
+                *i += 1;
-                let name = match tokens[i].clone() {
+                let name = match tokens[*i].clone() {
                     Token::Identifier(identifier) => identifier,
                     _ => todo!(),
                 };
 
-                i += 1;
+                *i += 1;
-                match tokens[i].clone() {
+                match tokens[*i].clone() {
                     Token::Equals => {}
                     _ => todo!(),
                 };
 
-                i += 1;
+                *i += 1;
 
                 let mut declaration_tokens: Vec<Token> = Vec::new();
-                while tokens[i] != Token::Semi {
+                while tokens[*i] != Token::Semi {
-                    declaration_tokens.push(tokens[i].clone());
+                    declaration_tokens.push(tokens[*i].clone());
-                    i += 1;
+                    *i += 1;
                 }
                 Statement::VariableDeclaration(name, parse_math(&declaration_tokens))
             }
             Token::Keyword(Keyword::Assign) => {
-                i += 1;
+                *i += 1;
-                let name = match tokens[i].clone() {
+                let name = match tokens[*i].clone() {
                     Token::Identifier(identifier) => identifier,
                     _ => todo!(),
                 };
 
-                i += 1;
+                *i += 1;
-                match tokens[i].clone() {
+                match tokens[*i].clone() {
                     Token::Equals => {}
                     _ => todo!(),
                 };
 
-                i += 1;
+                *i += 1;
 
                 let mut declaration_tokens: Vec<Token> = Vec::new();
-                while tokens[i] != Token::Semi {
+                while tokens[*i] != Token::Semi {
-                    declaration_tokens.push(tokens[i].clone());
+                    declaration_tokens.push(tokens[*i].clone());
-                    i += 1;
+                    *i += 1;
                 }
                 Statement::VariableAssignment(name, parse_math(&declaration_tokens))
             }
             Token::Identifier(identifier) => {
-                i += 1;
+                *i += 1;
 
                 let mut declaration_tokens: Vec<Vec<Token>> = Vec::new();
 
-                i += 1;
+                *i += 1;
-                while tokens[i] != Token::CloseParanthesis {
+                while tokens[*i] != Token::CloseParanthesis {
                     let mut argument_tokens: Vec<Token> = Vec::new();
-                    while tokens[i] != Token::Comma {
+                    while tokens[*i] != Token::Comma {
-                        argument_tokens.push(tokens[i].clone());
+                        argument_tokens.push(tokens[*i].clone());
-                        i += 1;
+                        *i += 1;
                     }
                     declaration_tokens.push(argument_tokens);
-                    i += 1;
+                    *i += 1;
                 }
 
-                i += 1;
+                *i += 1;
 
                 let mut arguments: Vec<ValueNode> = Vec::new();
 
@@ -150,19 +216,35 @@ fn parse_statements(tokens: &Vec<Token>, starting_i: usize) -> (Vec<Statement>,
                 Statement::FunctionCall(identifier.to_owned(), arguments)
             }
             Token::CloseSquiglyBracket => {
-                return (statements, i);
+                *i += 1;
+                return statements;
             }
             Token::Semi => {
-                i += 1;
+                *i += 1;
                 continue;
             }
             _other => {
                 dbg!(_other);
+                dbg!(i);
                 todo!()
             }
         });
     }
-    (statements, i)
+    *i += 1;
+    statements
+}
+
+pub fn parse_arguments(tokens: &Vec<Token>, i: &mut usize) -> Vec<String> {
+    let mut argument_variables = Vec::new();
+    while tokens[*i] != Token::OpenSquiglyBracket {
+        match &tokens[*i] {
+            Token::Identifier(identifier) => argument_variables.push(identifier.to_owned()),
+            Token::OpenSquiglyBracket => {}
+            _other => todo!(),
+        }
+        *i += 1;
+    }
+    argument_variables
 }
 
 pub fn ast(tokens: Vec<Token>) -> Vec<Function> {
@@ -172,18 +254,23 @@ pub fn ast(tokens: Vec<Token>) -> Vec<Function> {
     while i < tokens.len() {
         match &tokens[i] {
             Token::Keyword(Keyword::Function) => {
-                let (statements, added_to_i) = parse_statements(&tokens, i + 4);
+                i += 1;
-                let statements = vec![Statement::Scope(statements)];
+
-                let function_name = match &tokens[i + 1] {
+                let name = match &tokens[i] {
-                    Token::Identifier(identifier) => identifier.to_owned(),
+                    Token::Identifier(identifier) => identifier,
                     _ => todo!(),
-                };
+                }
-                let n_args = match &tokens[i + 2] {
+                .to_owned();
-                    Token::Number(num) => num.parse::<u64>().unwrap(),
+                i += 1;
-                    _ => todo!(),
+
-                };
+                let arguments = parse_arguments(&tokens, &mut i);
-                i += added_to_i;
+
-                functions.push(Function::new(function_name, n_args, statements));
+                i += 1;
+                let statements = parse_statements(&tokens, &mut i);
+
+                let statement = Statement::Scope(statements);
+
+                functions.push(Function::new(name, arguments, statement));
             }
             _other => {
                 dbg!(&functions);

src/tokeniser.rs

@@ -5,6 +5,8 @@ pub enum Token {
     Comma,
     Plus,
     Minus,
+    Ampersand,
+    Star,
     Number(String),
     Identifier(String),
     Keyword(Keyword),
@@ -85,22 +87,24 @@ fn tokenise_current_character(
             }
 
             {
-                use std::option::Option::Some as s;
+                use Option::Some as s;
                 use Token as T;
                 use TokenFinishedUnfinished::Unfinished as uf;
 
-                match current_character {
+                uf(match current_character {
-                    ';' => uf(s(T::Semi)),
+                    ';' => s(T::Semi),
-                    '(' => uf(s(T::OpenParanthesis)),
+                    '(' => s(T::OpenParanthesis),
-                    ')' => uf(s(T::CloseParanthesis)),
+                    ')' => s(T::CloseParanthesis),
-                    '{' => uf(s(T::OpenSquiglyBracket)),
+                    '{' => s(T::OpenSquiglyBracket),
-                    '}' => uf(s(T::CloseSquiglyBracket)),
+                    '}' => s(T::CloseSquiglyBracket),
-                    '=' => uf(s(T::Equals)),
+                    '=' => s(T::Equals),
-                    ',' => uf(s(T::Comma)),
+                    ',' => s(T::Comma),
-                    '+' => uf(s(T::Plus)),
+                    '+' => s(T::Plus),
-                    '-' => uf(s(T::Minus)),
+                    '-' => s(T::Minus),
-                    _ => uf(None),
+                    '&' => s(T::Ampersand),
-                }
+                    '*' => s(T::Star),
+                    _ => None,
+                })
             }
         }
         Some(v) => Finished(v),