Start implementation of vm.

sketching/goal_one.dm

@@ -0,0 +1,67 @@
+enum Option<T> {
+    Some(item: T),
+    None
+}
+
+fn make_one() = Some(1)
+
+fn main() {
+    if (make_one() is Some(num)) {
+        println(num)
+    }
+}
+
+// Bytecode?
+
+// Start with some magic number
+// Then a header. Each string starts with a length
+
+header {
+    module_name: default
+    symbol_table_addr: 25 // example
+    symbol_table_length: 104 // example
+    version: 0.1.0
+}
+
+symbols {
+    #   type    addr    len     name
+    0   fn      0       4       Some
+    1   fn      30      8       make_one
+    2   fn      39      4       main
+}
+
+layout Option {
+    [0]: byte // tag
+        - 0: Some
+        - 1: None
+    [1-8]: *Any // ptr to Any
+}
+
+fn Some(r0: *Any) -> *Option
+    alloc r1, 5         // allocate 5 bytes and put address into r1
+    mov [r1], 0         // move 0 into the (heap) location pointed to by r1
+    mov [r1 + 1], r0    // move the value of r0 into the location pointed to by r1 + 1
+    mov r0, r1          // move the value of r1 (the address of the struct) into r0
+    ret                 // return r0
+len: 30
+
+fn make_one:
+    mov r0, 1
+    call Some
+len: 9
+
+fn main:
+    call make_one       // op(1) + len(4) + name(8) = 13
+    cmp_int 0, [r0]     // op(1) + r(1) + offset(4) + operand(4) = 10
+    jne .end            // op(1) + offset(4)
+    mov r1, [r0 + 1]    // op(1) + dest_r(1) + src_r(1) + src_offset(4) = 7
+    mov r2, r1          // op(1) + dest_r(1) + src_r(1)
+    mov r0, r1          // op(1) + dest_r(1) + src_r(1)
+    call_ext println    // op(1) + len(4) + name(7)
+    free r2, 5          // op(1) + r(1) + size(4)
+
+    .end
+    mov r0, 0           // op(1) + r(1) + value(4)
+    ret                 // op(1)
+len:
+

sketching/hkt.dm

@@ -9,7 +9,7 @@ pub hkt Monad[T<A, B>] : Monad[T<B>] {
 }
 
 pub enum Option<T> : Monad {
-    Some(item) {
+    Some(item: T) {
         impl fn map(m) = Some(m(item))
         impl fn flat_map(m) = m(item)
     },

src/lexer/mod.rs

@@ -28,7 +28,7 @@ pub enum Token {
     Minus,
     Dot,
     Ellipsis,
-    Abstract
+    Abstract,
 }
 
 pub fn tokenize(input: &String) -> Result<Vec<Token>, &'static str> {
@@ -44,33 +44,25 @@ pub fn tokenize(input: &String) -> Result<Vec<Token>, &'static str> {
             ')' => tokens.push(Token::ParenClose),
             '<' => tokens.push(Token::LessThan),
             '>' => tokens.push(Token::GreaterThan),
-            '&' => {
-                match peekable.peek() {
-                    Some('&') => {
-                        let _ = peekable.next();
-                        tokens.push(Token::And);
-                    },
-                    Some(_) | None => tokens.push(Token::Intersection),
-                }
-            }
-            '|' => {
-                match peekable.next_if_eq(&'|') {
-                    Some(_) => tokens.push(Token::Or),
-                    None => tokens.push(Token::Union),
+            '&' => match peekable.peek() {
+                Some('&') => {
+                    let _ = peekable.next();
+                    tokens.push(Token::And);
                 }
+                Some(_) | None => tokens.push(Token::Intersection),
             },
-            '=' => {
-                match peekable.next_if_eq(&'>') {
-                    Some(_) => tokens.push(Token::BigArrow),
-                    None => tokens.push(Token::Equals),
-                }
+            '|' => match peekable.next_if_eq(&'|') {
+                Some(_) => tokens.push(Token::Or),
+                None => tokens.push(Token::Union),
+            },
+            '=' => match peekable.next_if_eq(&'>') {
+                Some(_) => tokens.push(Token::BigArrow),
+                None => tokens.push(Token::Equals),
             },
             '+' => tokens.push(Token::Plus),
-            '-' => {
-                match peekable.next_if_eq(&'>') {
-                    Some(_) => tokens.push(Token::LittleArrow),
-                    None => tokens.push(Token::Minus),
-                }
+            '-' => match peekable.next_if_eq(&'>') {
+                Some(_) => tokens.push(Token::LittleArrow),
+                None => tokens.push(Token::Minus),
             },
             '.' => {
                 let mut count = 1;
@@ -95,7 +87,7 @@ pub fn tokenize(input: &String) -> Result<Vec<Token>, &'static str> {
 
 fn match_identifier_or_keyword(start_char: char, peekable: &mut Peekable<Chars>) -> Option<Token> {
     if !is_valid_identifier_start_char(start_char) {
-        return None
+        return None;
     }
 
     // append start char
@@ -182,8 +174,7 @@ mod tests {
 
     #[test]
     fn ns_pub_mod_simple() {
-        let result = tokenize(&String::from("ns simple_ns\npub mod simple { }"))
-            .unwrap();
+        let result = tokenize(&String::from("ns simple_ns\npub mod simple { }")).unwrap();
         assert_eq!(Token::Namespace, result[0]);
         assert_eq!(Token::Identifier(String::from("simple_ns")), result[1]);
         assert_eq!(Token::Public, result[2]);

src/lib.rs

@@ -1 +1,2 @@
 mod lexer;
+mod vm;

src/vm/mod.rs

@@ -0,0 +1,136 @@
+mod op_codes;
+
+use op_codes::*;
+use std::alloc::{alloc_zeroed, Layout};
+
+pub fn run(code: &Vec<u8>, registers: &mut Vec<u64>, register_types: &mut Vec<RegisterType>) {
+    let mut i = 0;
+    while i < code.len() {
+        match code[i] {
+            MOV_INT => {
+                let target_register = code[i + 1] as usize;
+                let operand: u32 = code[i + 2] as u32
+                    + ((code[i + 3] as u32) << 8)
+                    + ((code[i + 4] as u32) << 16)
+                    + ((code[i + 5] as u32) << 24);
+                registers[target_register] = operand as u64;
+                register_types[target_register] = RegisterType::Int;
+                i += 6
+            }
+            MOV_LONG => {
+                let target_register = code[i + 1] as usize;
+                let operand: u64 = code[i + 2] as u64
+                    + ((code[i + 3] as u64) << 8)
+                    + ((code[i + 4] as u64) << 16)
+                    + ((code[i + 5] as u64) << 24)
+                    + ((code[i + 6] as u64) << 32)
+                    + ((code[i + 7] as u64) << 40)
+                    + ((code[i + 8] as u64) << 48)
+                    + ((code[i + 9] as u64) << 56);
+                registers[target_register] = operand;
+                register_types[target_register] = RegisterType::Long;
+                i += 10
+            }
+            MOV_DOUBLE => { /* todo */ }
+            MOV_REGISTER => {
+                let target_register = code[i + 1] as usize;
+                let source_register = code[i + 2] as usize;
+                registers[target_register] = registers[source_register];
+                register_types[target_register] = register_types[source_register].clone();
+                i += 3;
+            }
+            ALLOC => {
+                let target_register = code[i + 1] as usize;
+                let n_bytes_to_allocate = code[i + 2] as u32
+                    + ((code[i + 3] as u32) << 8)
+                    + ((code[i + 4] as u32) << 16)
+                    + ((code[i + 5] as u32) << 24);
+                let layout = Layout::from_size_align(n_bytes_to_allocate as usize, 4).unwrap();
+                let allocated = unsafe { alloc_zeroed(layout) };
+                registers[target_register] = allocated as u64;
+                register_types[target_register] = RegisterType::Pointer;
+                i += 6;
+            }
+            MOV_INT_TO => {
+                let target_register = code[i + 1] as usize;
+                if register_types[target_register] != RegisterType::Pointer {
+                    panic!("target_register {} is not a Pointer", target_register);
+                }
+                let offset = convert_to_u32(&code[(i + 2)..(i + 6)]) as isize;
+                let target = registers[target_register] as *mut u8;
+                unsafe {
+                    target.offset(offset).write(code[i + 6]);
+                    target.offset(offset + 1).write(code[i + 7]);
+                    target.offset(offset + 2).write(code[i + 8]);
+                    target.offset(offset + 3).write(code[i + 9]);
+                }
+                i += 10;
+            }
+            _ => panic!("Invalid code instruction"),
+        }
+    }
+}
+
+fn convert_to_u32(bytes: &[u8]) -> u32 {
+    bytes[0] as u32 | (bytes[1] as u32) << 8 | (bytes[2] as u32) << 16 | (bytes[3] as u32) << 24
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn init_registers(n_registers: usize) -> (Vec<u64>, Vec<RegisterType>) {
+        (vec![0; n_registers], vec![RegisterType::Int; n_registers])
+    }
+
+    #[test]
+    fn mov_1_as_int() {
+        let mut code = Vec::new();
+        add_mov_int(&mut code, 0, 1);
+        let (mut registers, mut register_types) = init_registers(1);
+        run(&code, &mut registers, &mut register_types);
+        assert_eq!(1, registers[0]);
+    }
+
+    #[test]
+    fn move_65535_as_int() {
+        let mut code = Vec::new();
+        add_mov_int(&mut code, 0, 0xffff);
+        let (mut registers, mut register_types) = init_registers(1);
+        run(&code, &mut registers, &mut register_types);
+        assert_eq!(0xffff, registers[0]);
+    }
+
+    #[test]
+    fn move_int_max_as_int() {
+        let mut code = Vec::new();
+        add_mov_int(&mut code, 0, 0xffff_ffff);
+        let (mut registers, mut register_types) = init_registers(1);
+        run(&code, &mut registers, &mut register_types);
+        assert_eq!(0xffff_ffff, registers[0]);
+    }
+
+    #[test]
+    fn move_register() {
+        let mut code = Vec::new();
+        add_mov_register(&mut code, 0, 1);
+        let (mut registers, mut register_types) = init_registers(2);
+        registers[1] = 1;
+        run(&code, &mut registers, &mut register_types);
+        assert_eq!(registers[0], 1);
+    }
+
+    #[test]
+    fn mov_int_to_register_as_address() {
+        let mut code = Vec::new();
+        add_alloc(&mut code, 0, 4);
+        add_mov_int_to(&mut code, 0, 0, 0xff);
+        let mut registers = vec![0; 16];
+        let mut register_types = vec![RegisterType::Int; 16];
+        run(&code, &mut registers, &mut register_types);
+        let target = registers[0] as *mut u8;
+        unsafe {
+            assert_eq!(0xff, *target);
+        }
+    }
+}

src/vm/op_codes.rs

@@ -0,0 +1,72 @@
+/// ## mov(register: u8, operand: u32)
+/// - 0: opcode
+/// - 1: register
+/// - 2..5: operand
+pub const MOV_INT: u8 = 0x00;
+
+pub const MOV_LONG: u8 = 0x01;
+pub const MOV_DOUBLE: u8 = 0x02;
+
+/// ## mov(target_register: u8, source_register: u8)
+/// 0: opcode
+/// 1: target_register
+/// 2: source_register
+pub const MOV_REGISTER: u8 = 0x03;
+
+/// ## alloc(register: u8, size: u32)
+/// 0: opcode
+/// 1: register
+/// 2..5: size
+pub const ALLOC: u8 = 0x04;
+
+/// ## mov_int_to(register: u8, offset: u32, operand: u32)
+/// 0: opcode
+/// 1: register
+/// 2..5: offset
+/// 6..9: operand
+pub const MOV_INT_TO: u8 = 0x05;
+
+pub const MOV_LONG_TO: u8 = 0x06;
+pub const MOV_DOUBLE_TO: u8 = 0x07;
+pub const MOV_REGISTER_TO: u8 = 0x08;
+
+#[derive(PartialEq, Eq, Clone)]
+pub enum RegisterType {
+    Int,
+    Long,
+    Double,
+    Pointer,
+}
+
+pub fn add_mov_int(code: &mut Vec<u8>, register: u8, operand: u32) {
+    code.push(MOV_INT);
+    code.push(register);
+    for b in operand.to_le_bytes() {
+        code.push(b);
+    }
+}
+
+pub fn add_mov_register(code: &mut Vec<u8>, target_register: u8, source_register: u8) {
+    code.push(MOV_REGISTER);
+    code.push(target_register);
+    code.push(source_register);
+}
+
+pub fn add_alloc(code: &mut Vec<u8>, register: u8, size: u32) {
+    code.push(ALLOC);
+    code.push(register);
+    for b in size.to_le_bytes() {
+        code.push(b);
+    }
+}
+
+pub fn add_mov_int_to(code: &mut Vec<u8>, register: u8, offset: u32, operand: u32) {
+    code.push(MOV_INT_TO);
+    code.push(register);
+    for b in offset.to_le_bytes() {
+        code.push(b);
+    }
+    for b in operand.to_le_bytes() {
+        code.push(b);
+    }
+}