parser

src/main.rs

@@ -3,7 +3,7 @@ use std::io;
 mod parser;
 
 fn main() -> Result<(), io::Error> {
-    let file = std::fs::read_to_string("test.asm")?;
+    let file = std::fs::read_to_string("../test.at")?;
     parser::run(&file);
     Ok(())
 }

src/parser.rs

@@ -1,5 +1,6 @@
 use dbg_pls::DebugPls;
-use logos::{Lexer, Logos};
+use logos::{Lexer, Logos, Span};
+use std::iter::Peekable;
 
 #[derive(Debug, Clone, PartialEq, Eq, Logos, DebugPls)]
 pub enum Token<'a> {
@@ -46,3 +47,117 @@ pub fn run(src: &str) {
     let tokens = lex(src).collect::<Vec<_>>();
     dbg_pls::color!(tokens);
 }
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Stmt {
+    pub kind: StmtKind,
+    pub span: Span,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum StmtKind {
+    Mov { to: Expr, from: Expr },
+    Add { to: Expr, value: Expr },
+    Sub { to: Expr, value: Expr },
+    Mul { to: Expr, value: Expr },
+    Div { to: Expr, value: Expr },
+    Jmp { to: Expr },
+    Je { to: Expr },
+    Cmp { rhs: Expr, lhs: Expr },
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Expr {
+    pub kind: ExprKind,
+    pub span: Span,
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum ExprKind {
+    Register,
+    Number,
+    Addr(Box<Expr>),
+}
+
+struct Parser<'a, I>
+where
+    I: Iterator<Item = Token<'a>>,
+{
+    iter: Peekable<I>,
+}
+
+struct CompilerError;
+
+type Result<T> = std::result::Result<T, CompilerError>;
+
+macro_rules! expect {
+    ($self:ident, $token:pat) => {
+        if let $token = $self.next()? {
+            return Err(CompilerError);
+        }
+    };
+}
+
+fn stmt(kind: StmtKind, span: Span) -> Stmt {
+    Stmt { kind, span }
+}
+
+impl<'a, I> Parser<'a, I>
+where
+    I: Iterator<Item = Token<'a>>,
+{
+    fn program(&mut self) -> Result<Vec<Stmt>> {
+        todo!()
+    }
+
+    fn stmt(&mut self) -> Result<Stmt> {
+        Ok(match self.next()? {
+            Token::Mov => {
+                let to = self.expr()?;
+                expect!(self, Token::Comma);
+                let from = self.expr()?;
+                stmt(StmtKind::Mov { to, from }, Default::default())
+            }
+            Token::Jmp => {
+                let to = self.expr()?;
+                Stmt {
+                    kind: StmtKind::Jmp { to },
+                    span: Default::default(),
+                }
+            }
+            Token::Je => {
+                let to = self.expr()?;
+                stmt(StmtKind::Je { to }, Default::default())
+            }
+            Token::Cmp => {
+                let lhs = self.expr()?;
+                expect!(self, Token::Comma);
+                let rhs = self.expr()?;
+                stmt(StmtKind::Cmp { lhs, rhs }, Default::default())
+            }
+            Token::Add => {}
+            Token::Sub => {}
+            Token::Mul => {}
+            Token::Div => {}
+            Token::BracketOpen => {}
+            Token::BracketClose => {}
+            Token::Comma => {}
+            Token::Label(_) => {}
+            Token::Number(_) => {}
+            Token::Word(_) => {}
+            Token::Error => {}
+        })
+    }
+
+    fn expr(&mut self) -> Result<Expr> {
+        todo!()
+    }
+
+    fn peek(&mut self) -> Result<&Token<'a>> {
+        self.iter.peek().ok_or(CompilerError)
+    }
+
+    fn next(&mut self) -> Result<Token<'a>> {
+        self.iter.next().ok_or(CompilerError)
+    }
+}