feat: some bytecode compiling

README.md

@@ -13,10 +13,10 @@ another lisp dialect
 
 Compliation flow:
 ```
-Input(file) -> Parser -> Interpret(TODO)
-  String       SExprs          IO
-                     |->  Compile(TODO)
-                              File 
+Input(file) -> Parser -> Compile(Bytecode) -> Interpret
+  String       SExprs        Bytecode            IO
+                                          |->  Compile
+                                              Assembly(?)
 ```
 
 ## Installation

src/compile.rs

@@ -0,0 +1,151 @@
+use std::fmt::Display;
+
+use crate::parser::Sexpr::{self, *};
+
+#[derive(Clone, Debug, Copy)]
+pub struct Register { value: i64 }
+
+impl Display for Register {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{}", self.value)
+    }
+}
+
+/// Literal types for the bytecode.
+#[derive(Clone, Debug)]
+pub enum Type {
+    Int(i64),
+    Float(f64),
+    Bool(bool),
+    String(String),
+}
+
+impl Display for Type {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Type::Int(i) => write!(f, "{}", i),
+            Type::Float(fl) => write!(f, "{}", fl),
+            Type::Bool(b) => write!(f, "{}", b),
+            Type::String(s) => write!(f, "{}", s),
+        }
+    }
+}
+
+/// Instructions for the bytecode.
+#[derive(Clone, Debug)]
+pub enum Instr {
+    /// Call(Function Index, Arguments)
+    Call(usize, [Register; 6]),
+
+    /// Stack manipulators
+    Push(usize, Type), Pop(usize, Register),
+
+    JumpIfFalse(usize, Register, usize),
+}
+
+impl Display for Instr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Instr::Call(idx, args)         => write!(f, "{} call {} {} {} {} {} {}", idx, args[0], args[1], args[2], args[3], args[4], args[5]),
+            Instr::Push(idx, t)            => write!(f, "{} push {}", idx, t),
+            Instr::Pop(idx, r)             => write!(f, "{} pop {}", idx, r),
+            Instr::JumpIfFalse(idx, r, to) => write!(f, "{} jmpf {} {}", idx, r, to),
+        }
+    }
+}
+
+pub struct Compiler {
+    /// The bytecode.
+    pub bytecode: Vec<Instr>,
+    /// The stack.
+    pub stack: Vec<Type>,
+    /// The current register index.
+    pub register: Register,
+    /// The current label index.
+    pub label: usize,
+}
+
+impl Compiler {
+    pub fn new() -> Compiler {
+        Compiler {
+            bytecode: Vec::new(),
+            stack: Vec::new(),
+            register: Register { value: 1 },
+            label: 0,
+        }
+    }
+
+    fn next_register(&mut self) -> Register {
+        let r = self.register;
+        self.register.value += 1;
+        r
+    }
+
+    fn next_label(&mut self) -> usize {
+        let l = self.label;
+        self.label += 1;
+        l
+    }
+
+    pub fn compile_sexpr(&mut self, ast: Sexpr) -> Vec<Instr> {
+        let mut result: Vec<Instr> = Vec::new();
+    
+        match ast {
+            Cons(car, cdr) => {
+                match *car {
+                    Symbol(f) => {
+                        match f.as_str() {
+                            "do" => {
+                                for c in cdr {
+                                    result.append(&mut self.compile_sexpr(c));
+                                }
+                            },
+                            "print" => {
+                                let function_register = self.next_register();
+                                result.push(Instr::Push(self.next_label(), Type::Int(1)));
+                                result.push(Instr::Pop(self.next_label(), function_register));
+
+                                let arg = &cdr[0];
+                                let instrs = &mut self.compile_ast(arg);
+                                result.append(&mut instrs.clone());
+
+                                let arg_register = match instrs.last().unwrap() {
+                                    Instr::Pop(_, r) => *r,
+                                    _ => panic!("Expected mov instruction in `print`"),
+                                };
+
+                                result.push(
+                                    Instr::Call(self.next_label(), [
+                                        function_register,
+                                        arg_register,
+                                        Register { value: 0 },
+                                        Register { value: 0 },
+                                        Register { value: 0 },
+                                        Register { value: 0 }
+                                        ])
+                                );
+                            },
+                            _ => todo!(),
+                        }
+                    },
+                    _ => todo!(),
+                }
+            },
+            _ => todo!()
+        }
+
+        result
+    }
+
+    fn compile_ast(&mut self, ast: &Sexpr) -> Vec<Instr> {
+        let mut result = Vec::new();
+        match ast {
+            Str(s) => {
+                result.push(Instr::Push(self.next_label(), Type::String(format!("\"{}\"", s))));
+                result.push(Instr::Pop(self.next_label(), self.next_register()));
+            },
+            _ => todo!()
+        }
+        result
+    }
+}

src/main.rs

@@ -1,4 +1,4 @@
-use std::{fs::read_to_string, path::Path};
+use std::{fs::{read_to_string, File}, path::Path, io::Write};
 
 use structopt::StructOpt;
 
@@ -11,18 +11,29 @@ use util::cover_paren;
 mod parser;
 use parser::{tokenize, Parser};
 
+mod compile;
+use compile::Compiler;
+
 fn main() {
     let args = Args::from_args();
     
     let src = cover_paren(read_to_string(&args.file).unwrap());
-    let _file_name = Path::new(&args.file).file_stem().unwrap().to_str().unwrap();
+    let file_name = Path::new(&args.file).file_stem().unwrap().to_str().unwrap();
     
     let tokens = tokenize(&src);
     let mut parser = Parser::new(tokens.clone());
     let result = parser.parse();
 
     match args.verbose {
-        0 => println!("We don't do anything yet."),
+        0 => {
+            let mut compiler = Compiler::new();
+            let instrs = compiler.compile_sexpr(result.unwrap());
+            
+            let mut file = File::create(format!("{}.bbb", file_name)).unwrap();
+            for instr in instrs {
+                file.write_all(format!("{}\n", instr).as_bytes()).unwrap();
+            }
+        },
         1 => println!("{:?}", result),
         2 | _ => {
             println!("Tokens: {:?}", tokens);

src/parser.rs

@@ -9,6 +9,27 @@ pub enum Sexpr {
     Nil,
 }
 
+impl std::fmt::Display for Sexpr {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Int(i) => write!(f, "{}", i),
+            Float(fl) => write!(f, "{}", fl),
+            Str(s) => write!(f, "{}", s),
+            Boolean(b) => write!(f, "{}", b),
+            Symbol(s) => write!(f, "{}", s),
+            Cons(car, cdr) => {
+                write!(f, "(")?;
+                write!(f, "{}", car)?;
+                for c in cdr {
+                    write!(f, " {}", c)?;
+                }
+                write!(f, ")")
+            },
+            Nil => write!(f, "nil"),
+        }
+    }
+}
+
 pub type ParseResult = Result<Sexpr, String>;
 
 pub struct Parser {