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11 changed files with 237 additions and 464 deletions

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@ -1,14 +0,0 @@
LunarWaveVM is a Lua 5.4 virtual machine written in Rust.
![A star field with an orange crab-shaped nebula facing a dark purple moon with a bright magenta crescent.](pictures/lunar wave crab nebula.jpeg)
# Roadmap
- [x] Loading simple pre-compiled bytecode programs
- [x] Hash tables
- [x] Fizzbuzz
- [ ] Closures
- [ ] Garbage collection
- [ ] Long strings
- [ ] Using arrays internally for tables
- [ ] Compiling Lua source code to bytecode

176
notes.md Normal file
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@ -0,0 +1,176 @@
Lua source code
`hello.lua`
```lua
print "Hello."
```
`math.lua`
```lua
local function add (a, b)
return a + b
end
print (("1 + 2 = %i"):format (add (1, 2)))
```
luac5.4 listing
```
main <hello.lua:0,0> (5 instructions at 0x564f4fd74cc0)
0+ params, 2 slots, 1 upvalue, 0 locals, 2 constants, 0 functions
1 [1] VARARGPREP 0
2 [1] GETTABUP 0 0 0 ; _ENV "print"
3 [1] LOADK 1 1 ; "Hello."
4 [1] CALL 0 2 1 ; 1 in 0 out
5 [1] RETURN 0 1 1 ; 0 out
```
```
main <math.lua:0,0> (12 instructions at 0x55ee2417acc0)
0+ params, 7 slots, 1 upvalue, 1 local, 3 constants, 1 function
1 [1] VARARGPREP 0
2 [3] CLOSURE 0 0 ; 0x55ee2417b000
3 [5] GETTABUP 1 0 0 ; _ENV "print"
4 [5] LOADK 2 1 ; "1 + 2 = %i"
5 [5] SELF 2 2 2k ; "format"
6 [5] MOVE 4 0
7 [5] LOADI 5 1
8 [5] LOADI 6 2
9 [5] CALL 4 3 0 ; 2 in all out
10 [5] CALL 2 0 0 ; all in all out
11 [5] CALL 1 0 1 ; all in 0 out
12 [5] RETURN 1 1 1 ; 0 out
function <math.lua:1,3> (4 instructions at 0x55ee2417b000)
2 params, 3 slots, 0 upvalues, 2 locals, 0 constants, 0 functions
1 [2] ADD 2 0 1
2 [2] MMBIN 0 1 6 ; __add
3 [2] RETURN1 2
4 [3] RETURN0
```
```
main <test_vectors/is_93.lua:0,0> (14 instructions at 0x559f55e1ecd0)
0+ params, 2 slots, 1 upvalue, 1 local, 5 constants, 1 function
1 [1] VARARGPREP 0
2 [1] GETTABUP 0 0 0 ; _ENV "arg"
3 [1] GETI 0 0 1
4 [1] EQK 0 1 0 ; "93"
5 [1] JMP 4 ; to 10
6 [2] GETTABUP 0 0 2 ; _ENV "print"
7 [2] LOADK 1 3 ; "it's 93"
8 [2] CALL 0 2 1 ; 1 in 0 out
9 [2] JMP 3 ; to 13
10 [4] GETTABUP 0 0 2 ; _ENV "print"
11 [4] LOADK 1 4 ; "it's not 93"
12 [4] CALL 0 2 1 ; 1 in 0 out
13 [9] CLOSURE 0 0 ; 0x559f55e1f3d0
14 [9] RETURN 1 1 1 ; 0 out
constants (5) for 0x559f55e1ecd0:
0 S "arg"
1 S "93"
2 S "print"
3 S "it's 93"
4 S "it's not 93"
locals (1) for 0x559f55e1ecd0:
0 unused_fn 14 15
upvalues (1) for 0x559f55e1ecd0:
0 _ENV 1 0
function <test_vectors/is_93.lua:7,9> (4 instructions at 0x559f55e1f3d0)
0 params, 2 slots, 1 upvalue, 0 locals, 2 constants, 0 functions
1 [8] GETTABUP 0 0 0 ; _ENV "print"
2 [8] LOADK 1 1 ; "unused"
3 [8] CALL 0 2 1 ; 1 in 0 out
4 [9] RETURN0
constants (2) for 0x559f55e1f3d0:
0 S "print"
1 S "unused"
locals (0) for 0x559f55e1f3d0:
upvalues (1) for 0x559f55e1f3d0:
0 _ENV 0 0
```
Octal dump of luac5.4 byte code
```
0000000 1b 4c 75 61 54 00 19 93 0d 0a 1a 0a 04 08 08 78 >.LuaT..........x<
0000020 56 00 00 00 00 00 00 00 00 00 00 00 28 77 40 01 >V...........(w@.<
0000040 8b 40 68 65 6c 6c 6f 2e 6c 75 61 80 80 00 01 02 >.@hello.lua.....<
0000060 85 51 00 00 00 0b 00 00 00 83 80 00 00 44 00 02 >.Q...........D..<
0000100 01 46 00 01 01 82 04 86 70 72 69 6e 74 04 87 48 >.F......print..H<
0000120 65 6c 6c 6f 2e 81 01 00 00 80 85 01 00 00 00 00 >ello............<
0000140 80 80 81 85 5f 45 4e 56 >...._ENV<
0000150
```
```
0000000 1b 4c 75 61 54 00 19 93 0d 0a 1a 0a 04 08 08 78 >.LuaT..........x<
0000020 56 00 00 00 00 00 00 00 00 00 00 00 28 77 40 01 >V...........(w@.<
0000040 8a 40 6d 61 74 68 2e 6c 75 61 80 80 00 01 07 8c >.@math.lua......<
0000060 51 00 00 00 4f 00 00 00 8b 00 00 00 03 81 00 00 >Q...O...........<
0000100 14 81 02 02 00 02 00 00 81 02 00 80 01 83 00 80 >................<
0000120 44 02 03 00 44 01 00 00 c4 00 00 01 c6 00 01 01 >D...D...........<
0000140 83 04 86 70 72 69 6e 74 04 8b 31 20 2b 20 32 20 >...print..1 + 2 <
0000160 3d 20 25 69 04 87 66 6f 72 6d 61 74 81 01 00 00 >= %i..format....<
0000200 81 80 81 83 02 00 03 84 22 01 00 01 2e 00 01 06 >........".......<
0000220 48 01 02 00 47 01 01 00 80 80 80 84 01 00 00 01 >H...G...........<
0000240 80 82 82 61 80 84 82 62 80 84 80 8c 01 02 02 00 >...a...b........<
0000260 00 00 00 00 00 00 00 00 80 81 84 61 64 64 82 8c >...........add..<
0000300 81 85 5f 45 4e 56 >.._ENV<
0000306
```
# Interpretation of byte code
Overall structure
- Roughly 32 byte header with magic number, version number, etc.
- File name
- `80 80 00 01 02 85` header for main function
- Packed 4-byte instructions for main function
- `82` or `83` length prefix for string table
- String table for main function
- `81 01 00 00 81 80 81 83 02 00 03 84` header for "add" function
- Packed 4-byte instructions for "add" function
- `80 80 80 84 01 00 00 01 80` Header for file-scope debug symbols?
- File-scope debug symbols?
- String table for entire file?
## Bytecodes
Per lopcodes.h, instructions are 32 bits long, always.
The opcode is encoded in the first (highest?) 7 bits.
```
83 80 00 00 ; 0x03 = 3 = LOADK
0b 00 00 00 ; 0x0b = 11 = GETTABUP
22 01 00 01 ; 0x22 = 34 = ADD
2e 00 01 06 ; 0x2e = 46 = MMBIN
c4 00 00 01 ; 0xc4 = 68 = CALL
44 00 02 01 ; 0x44 = 68 = CALL
46 00 01 01 ; 0x46 = 70 = RETURN
47 01 01 00 ; 0x47 = 71 = RETURN0
48 01 02 00 ; 0x48 = 72 = RETURN1
51 00 00 00 ; 0x51 = 81 = VARARGPREP
```
## Strings
Filenames are encoded at the top, and there's a string table at the bottom.
Strings appear to be prefixed with a variable-length length prefix.
There is an extra byte before each string which I can't account for,
and the lengths seem to be off by one, e.g. 0x84 is a length of 3, not 4.
| --- |
| "add" | 81 84 61 64 64
| "_ENV" | 81 85 5f 45 4e 56
| "print" | 04 86 70 72 69 6e 74
| "format" | 04 87 66 6f 72 6d 61 74
| "@math.lua" | 01 8a 40 6d 61 74 68 2e 6c 75 61
| "1 + 2 = %i" | 04 8b 31 20 2b 20 32 20 3d 20 25 69

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@ -5,24 +5,14 @@ pub enum Instruction {
Call (u8, u8, u8),
Closure (u8, u32),
EqI (u8, i8, bool),
// Equals Constant?
EqK (u8, u8, bool),
ExtraArg (u32),
ForLoop (u8, u32),
ForPrep (u8, u32),
GetField (u8, u8, u8),
// Get Immediate?
GetI (u8, u8, u8),
GetTable (u8, u8, u8),
// Get Table, Upvalue
GetTabUp (u8, u8, u8),
@ -49,10 +39,6 @@ pub enum Instruction {
// MetaMethod, Binary
MmBin (u8, u8, u8),
MmBinK (u8, u8, u8, bool),
ModK (u8, u8, u8),
Move (u8, u8),
Mul (u8, u8, u8),
@ -69,12 +55,6 @@ pub enum Instruction {
// Return just one register
Return1 (u8),
SetField (u8, u8, u8, bool),
SetI (u8, u8, u8, bool),
SetList (u8, u8, u8, bool),
SetTabUp (u8, u8, u8),
TailCall (u8, u8, u8, bool),

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@ -43,11 +43,6 @@ pub (crate) fn compile_bytecode (source: Vec <u8>) -> Vec <u8> {
output.stdout.as_slice ().to_vec ()
}
fn i_sb (buf: [u8; 4]) -> Option <i8> {
let b = buf [2];
i8::try_from (i32::try_from (b).ok ()? - 127).ok ()
}
pub fn parse_inst (buf: [u8; 4]) -> Option <Inst>
{
let opcode = buf [0] & 0x7f;
@ -74,21 +69,14 @@ pub fn parse_inst (buf: [u8; 4]) -> Option <Inst>
0x08 => Inst::LoadNil (a),
0x09 => Inst::GetUpVal (a, b),
0x0b => Inst::GetTabUp (a, b, c),
0x0c => Inst::GetTable (a, b, c),
0x0d => Inst::GetI (a, b, c),
0x0e => Inst::GetField (a, b, c),
0x0f => Inst::SetTabUp (a, b, c),
0x11 => Inst::SetI (a, b, c, k),
0x12 => Inst::SetField (a, b, c, k),
0x13 => Inst::NewTable (a),
0x19 => Inst::ModK (a, b, c),
0x22 => Inst::Add (a, b, c),
0x24 => Inst::Mul (a, b, c),
0x2e => Inst::MmBin (a, b, c),
0x30 => Inst::MmBinK (a, b, c, k),
0x33 => Inst::Not (a, b),
0x3c => Inst::EqK (a, b, k),
0x3d => Inst::EqI (a, i_sb (buf)?, k),
0x38 => Inst::Jmp (s_j),
0x42 => Inst::Test (a, k),
0x44 => Inst::Call (a, b, c),
@ -96,9 +84,6 @@ pub fn parse_inst (buf: [u8; 4]) -> Option <Inst>
0x46 => Inst::Return (a, b, c, k),
0x47 => Inst::Return0,
0x48 => Inst::Return1 (a),
0x49 => Inst::ForLoop (a, bx),
0x4a => Inst::ForPrep (a, bx),
0x4e => Inst::SetList (a, b, c, k),
0x4f => Inst::Closure (a, bx),
0x51 => Inst::VarArgPrep (a.into ()),
0x52 => Inst::ExtraArg (ax),
@ -133,23 +118,11 @@ fn parse_byte <R: Read> (rdr: &mut R) -> Option <u8>
Some (buf [0])
}
fn parse_float <R: Read> (rdr: &mut R) -> Option <f64> {
let mut buf = [0u8; 8];
rdr.read_exact (&mut buf).ok ()?;
Some (f64::from_ne_bytes(buf))
}
fn parse_int <R: Read> (rdr: &mut R) -> Option <u32>
{
Some ((parse_byte (rdr)? - 0x80) as u32)
}
fn parse_i64 <R: Read> (rdr: &mut R) -> Option <i64> {
let mut buf = [0u8; 8];
rdr.read_exact (&mut buf).ok ()?;
Some (i64::from_ne_bytes(buf))
}
// I'm doing this recursively so it's easy to match with the PUC Lua
// code, but I don't like recursion in general, and I don't know
// why PUC wrote it that way.
@ -159,8 +132,6 @@ pub fn parse_block <R: Read> (rdr: &mut R, blocks: &mut Vec <Block>)
{
// Ignore things I haven't implemented yet
use crate::value::Value;
parse_string (rdr)?; // function name
parse_int (rdr)?; // start line in source code
parse_int (rdr)?; // last line in source code
@ -181,18 +152,12 @@ pub fn parse_block <R: Read> (rdr: &mut R, blocks: &mut Vec <Block>)
let mut constants = Vec::with_capacity (constant_count as usize);
for i in 0..constant_count {
// LUA_TNIL and friends from `lua.h` in PUC Lua
for _ in 0..constant_count {
let const_type = parse_byte (rdr)?;
assert_eq! (const_type, 0x04);
let val = match const_type {
3 => Value::from (parse_i64 (rdr)?),
4 => parse_string (rdr)?.into (),
19 => Value::from (parse_float (rdr)?),
x => panic! ("Constant {} has type {}", i, x),
};
constants.push (val);
let s = parse_string (rdr)?;
constants.push (s.into ());
}
let upvalue_count = parse_int (rdr)? as usize;

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@ -1,5 +1,3 @@
// cargo run -- --script test_vectors/fizz_buzz.lua
mod instruction;
mod loader;
mod state;
@ -11,21 +9,8 @@ mod tests;
fn main () {
use state::State;
let mut script = String::from ("test_vectors/hello.lua");
let mut args = std::env::args ();
let exe_name = args.next ().unwrap ();
while let Some (arg) = args.next () {
match arg.as_str () {
"--script" => script = args.next ().unwrap (),
"--" => break,
_ => panic! ("can't parse args"),
}
}
let lua_file = {
let source = std::fs::read (script).expect ("couldn't load Lua source code");
let source = std::fs::read ("test_vectors/hello.lua").expect ("couldn't load Lua source code");
let bytecode = loader::compile_bytecode(source);
let mut rdr = std::io::Cursor::new (bytecode);
loader::parse_chunk (&mut rdr).unwrap ()
@ -36,7 +21,7 @@ fn main () {
vm.debug_print = true;
}
let upvalues = State::upvalues_from_args ([exe_name].into_iter ().chain (args));
let upvalues = State::upvalues_from_args (std::env::args ());
vm.breakpoints.push (state::Breakpoint {
block_idx: 3,

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@ -1,9 +1,10 @@
use std::rc::Rc;
use std::collections::HashMap;
use crate::{
instruction::Instruction,
value::{
BogusClosure,
Table,
Value,
},
};
@ -40,8 +41,6 @@ pub struct Breakpoint {
#[derive (Debug)]
pub struct State {
registers: Vec <Value>,
// Currently only used for native function calls
top: usize,
stack: Vec <StackFrame>,
pub debug_print: bool,
@ -53,7 +52,6 @@ impl Default for State {
fn default () -> Self {
Self {
registers: vec! [Value::Nil; 16],
top: 0,
stack: vec! [
StackFrame {
program_counter: 0,
@ -68,35 +66,18 @@ impl Default for State {
}
}
fn lw_print (l: &mut State) -> i32 {
for i in 0..u8::try_from (l.get_top ()).unwrap () {
let input = l.reg (i);
if i == 0 {
print! ("{input}");
}
else {
print! ("\t{input}");
}
}
println! ("");
*l.reg_mut (0) = Value::from (1993);
1
}
impl State {
pub fn upvalues_from_args <I: Iterator <Item = String>> (args: I) -> Vec <Value>
{
let arg = args.map (|s| Value::from (s)).enumerate ();
let arg = Value::from_iter (arg.map (|(i, v)| (Value::from (i), v)));
let arg: Vec <_> = args.map (|s| s.to_string ()).collect ();
let env = [
("arg", arg),
("print", Value::RsFunc (lw_print)),
].into_iter ().map (|(k, v)| (k.to_string (), v));
let env = HashMap::from_iter ([
("arg", Value::BogusArg (arg.into ())),
("print", Value::BogusPrint),
].map (|(k, v)| (k.to_string (), v)));
vec! [
Value::from_iter (env.into_iter ()),
Value::BogusEnv (env.into ()),
]
}
@ -117,11 +98,6 @@ impl State {
&mut self.registers [frame.register_offset + i as usize]
}
// For native functions to check how many args they got
pub fn get_top (&self) -> usize {
self.top - self.stack.last ().unwrap ().register_offset
}
pub fn execute_chunk (&mut self, chunk: &Chunk, upvalues: &[Value])
-> Vec <Value> {
let max_iters = 2000;
@ -160,9 +136,7 @@ impl State {
*self.reg_mut (*a) = Value::from (v_b + v_c);
},
Instruction::Call (a, b, _c) => {
let b = usize::from (*b);
Instruction::Call (a, _b, c) => {
// Take arguments from registers [a + 1, a + b)
// Call the function in register [a]
// Return values in registers [a, a + c - 1)
@ -171,10 +145,9 @@ impl State {
//
// e.g. CALL 0 2 1 mean "Call 0 with 1 argument, return 1 value", like for printing a constant
// Do a clone here to avoid a borow problem.
// Should be fixable with more clever code.
// TODO: Only implement printing values for now
let v_a = self.reg (*a).clone ();
let v_a = self.reg (*a);
match v_a {
Value::BogusClosure (rc) => {
@ -200,27 +173,17 @@ impl State {
// Skip the PC increment at the bottom of the loop
continue;
},
Value::RsFunc (x) => {
let current_frame = self.stack.last ().unwrap ();
let new_offset = current_frame.register_offset + usize::from (*a) + 1;
self.stack.push (StackFrame {
program_counter: 65535, // Bogus for native functions
block_idx: 65535, // Bogus
register_offset: new_offset,
});
Value::BogusPrint => {
// In real Lua, print is a function inside
// the runtime. Here it's bogus.
// No clue what the '1' is doing here
self.top = new_offset + b - 1;
// assert_eq! (*b, 2);
assert_eq! (*c, 1);
// Call
let num_results = x (self);
let value = self.reg (a + 1);
println! ("{}", value);
let popped_frame = self.stack.pop ().unwrap ();
let offset = popped_frame.register_offset - 1;
for i in (offset)..(offset + usize::try_from (num_results).unwrap ()) {
self.registers [i] = self.registers [i + 1 + usize::from (*a)].take ();
}
*self.reg_mut (*a) = self.reg_mut (*a + 1).take ();
},
_ => {
let stack = &self.stack;
@ -236,12 +199,6 @@ impl State {
upvalues: vec! [],
}.into ());
},
Instruction::EqI (a, sb, k_flag) => {
if (self.reg (*a).as_int ().unwrap () == *sb as i64) != *k_flag
{
next_pc += 1;
}
},
Instruction::EqK (a, b, k_flag) => {
let b = usize::from (*b);
@ -255,73 +212,30 @@ impl State {
assert_eq! (*ax, 0, "implemented only for ax == 0");
},
Instruction::ForLoop (a, bx) => {
let mut iter = self.reg (*a + 3).as_int ().unwrap ();
iter += 1;
*self.reg_mut (*a + 3) = iter.into ();
let stop = self.reg (*a + 1).as_int ().unwrap ();
if iter <= stop {
next_pc -= i32::try_from (*bx).unwrap ();
}
},
Instruction::ForPrep (a, bx) => {
let start = self.reg (*a).as_int ().unwrap ();
let stop = self.reg (*a + 1).as_int ().unwrap ();
if start > stop {
next_pc += i32::try_from (*bx).unwrap () + 1;
}
*self.reg_mut (*a + 3) = start.into ();
},
Instruction::GetField (a, b, c) => {
let t = match self.reg (*b) {
Value::Table (t) => t,
_ => panic! ("R[B] must be a table"),
};
let key = match &k [usize::from (*c)] {
Value::String (s) => s,
_ => panic! ("K[C] must be a string"),
};
let val = t.borrow ().get (Value::String (Rc::clone (key)));
*self.reg_mut (*a) = val;
},
Instruction::GetTable (a, b, c) => {
let t = match self.reg (*b) {
Value::Table (t) => t,
_ => panic! ("R[B] must be a table"),
};
let key = self.reg (*c);
let val = t.borrow ().get (key.clone ());
*self.reg_mut (*a) = val;
},
Instruction::GetTabUp (a, b, c) => {
let b = usize::try_from (*b).unwrap ();
let c = usize::try_from (*c).unwrap ();
let table = upvalues.get (b).unwrap ().as_table ().expect ("GetTabUp only works on tables").borrow ();
let env = match upvalues.get (b).unwrap () {
Value::BogusEnv (x) => x,
_ => panic! ("Only allowed upvalue is BogusEnv"),
};
let key = match k.get (c).unwrap () {
Value::String (s) => String::from (s.as_ref()),
Value::String (s) => s.as_ref (),
_ => panic! ("GetTabUp only supports string keys"),
};
*self.reg_mut (*a) = table.get (key);
let value = env.get (key).unwrap ();
*self.reg_mut (*a) = value.clone ();
},
Instruction::GetI (a, b, c) => {
let key = i64::try_from (*c).unwrap ();
let c = usize::try_from (*c).unwrap ();
let value = {
let table = self.reg (*b).as_table ().expect ("GetI only works on tables").borrow ();
table.get (key)
let table = self.reg (*b);
let value = match table {
Value::BogusArg (arg) => arg.get (c).map (|x| x.as_str().into ()).unwrap_or_default(),
_ => unimplemented!(),
};
*self.reg_mut (*a) = value;
@ -369,15 +283,6 @@ impl State {
panic! ("Not sure how to implememtn OP_MMBIN for these 2 values {a:?}, {b:?}");
}
},
Instruction::MmBinK (_a, _b, _c, _k) => {
// Ignore
},
Instruction::ModK (a, b, c) => {
let b = self.reg (*b).as_int().unwrap ();
let c = k [usize::from (*c)].as_int ().unwrap ();
*self.reg_mut (*a) = (b % c).into ();
},
Instruction::Move (a, b) => {
*self.reg_mut (*a) = self.reg (*b).clone ();
},
@ -466,55 +371,6 @@ impl State {
let offset = popped_frame.register_offset;
self.registers [offset - 1] = self.registers [offset + a].take ();
},
Instruction::SetField (a, b, c, k_flag) => {
let value = if *k_flag {
&k [usize::from (*c)]
}
else {
self.reg (*c)
}
.clone ();
let b = usize::try_from (*b).unwrap ();
let key = match k.get (b).unwrap () {
Value::String (s) => s.as_ref (),
_ => panic! ("GetTabUp only supports string keys"),
};
let mut dst = self.reg (*a).as_table ()
.expect ("SetField only works on tables").borrow_mut ();
dst.insert (Value::from (key.as_str ()), value);
},
Instruction::SetI (a, b, c, k_flag) => {
let value = if *k_flag {
&k [usize::from (*c)]
}
else {
self.reg (*c)
}
.clone ();
let mut dst = self.reg_mut (*a).as_table ().expect ("SetI only works on tables").borrow_mut ();
dst.insert (i64::from (*b), value);
},
Instruction::SetList (a, b, c, k) => {
if *b == 0 {
panic! ("SetList with b == 0 not implemented");
}
if *k {
panic! ("SetList with k = true not implemented");
}
let mut dst = self.reg (*a).as_table ().expect ("SetList only works on tables").borrow_mut ();
for i in 1..=*b {
let src = self.reg (*a + i);
dst.insert (Value::from (i64::from (*c + i)), src.clone ());
}
},
Instruction::SetTabUp (_a, _b, _c) => unimplemented! (),
Instruction::TailCall (_a, _b, _c, _k) => unimplemented! (),
Instruction::Test (a, _k) => {

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@ -214,64 +214,6 @@ fn fma () {
}
}
#[test]
fn heap () {
use std::{
cell::RefCell,
collections::HashMap,
rc::Rc,
};
use crate::value::Table;
{
let mut allocations = HashMap::new ();
let mut ctr = 0;
let c = ctr;
allocations.insert (ctr, Table::default ());
ctr += 1;
let a = ctr;
allocations.insert (ctr, Table::default ());
ctr += 1;
allocations.get_mut (&a).unwrap ().insert (1, c);
allocations.get_mut (&c).unwrap ().insert (2, "eee");
}
if true {
#[derive (Clone, Debug, PartialEq)]
enum Value {
S (Rc <String>),
T (Rc <RefCell <HashMap <i64, Value>>>),
}
let c = Value::T (Default::default ());
let a = Value::T (Default::default ());
match &a {
Value::T (t) => t.borrow_mut ().insert (1, c.clone ()),
_ => panic! ("impossible"),
};
match &c {
Value::T (t) => t.borrow_mut ().insert (2, Value::S (Rc::new (String::from ("eee")))),
_ =>panic! ("impossible"),
};
let actual = match &a {
Value::T (t) => match t.borrow ().get (&1) {
Some (Value::T (t)) => t.borrow ().get (&2).unwrap ().clone (),
_ => panic! ("impossible"),
},
_ => panic! ("impossible"),
};
assert_eq! (actual, Value::S (Rc::new ("eee".into ())));
}
}
#[test]
fn is_93 () {
assert_eq! (Value::from ("93"), Value::from ("93"));
@ -301,74 +243,6 @@ fn is_93 () {
assert_eq! (run (&["", "94"], &chunk), vec! [Value::from (1)]);
}
#[test]
fn native_functions () {
fn add (l: &mut State) -> i32 {
0
}
fn multiply (l: &mut State) -> i32 {
0
}
fn greet (l: &mut State) -> i32 {
0
}
let _funcs = [
add,
multiply,
greet,
];
}
#[test]
fn tables_1 () {
// I don't capture stdout yet, but I can at least make sure basic table
// operations don't crash
let src = r#"
print " 1"
print (nil)
print (false)
print (true)
print (1993)
print (1993.00)
print "Hello."
print " 2"
local t = {}
print (t)
print (t [1])
t [1] = "asdf"
print (t [1])
t.x = 1993
print (t.x)
t.t = { 3.14159 }
print (t ["t"][1])
"#;
run_source (&[], src);
}
#[test]
fn tables_2 () {
let src = r#"
print " 3"
local c = {}
local a = { c }
print (a [1])
c [2] = "eee"
print (a [2])
"#;
run_source (&[], src);
}
#[test]
fn value_size () {
// Per https://www.lua.org/doc/jucs05.pdf,
@ -380,7 +254,9 @@ fn value_size () {
// It would be nice if LunarWaveVM is the same or better.
// There are some exploratory things in this test, too
use std::mem::size_of;
use std::{
mem::size_of,
};
assert! (size_of::<Box <()>> () <= 8);
assert! (size_of::<std::rc::Rc <()>> () <= 8);

View File

@ -1,5 +1,4 @@
use std::{
cell::RefCell,
cmp::{
Eq,
PartialEq,
@ -25,14 +24,16 @@ pub enum Value {
Float (f64),
Integer (i64),
RsFunc (fn (&mut crate::state::State) -> i32),
String (Rc <String>),
Table (Rc <RefCell <Table>>),
Table (Rc <Table>),
// These are all bogus, I haven't figured out how to implement
// closures yet
// tables and function pointers yet
BogusArg (Rc <Vec <String>>),
BogusClosure (Rc <BogusClosure>),
BogusEnv (Rc <HashMap <String, Value>>),
BogusPrint,
}
impl Default for Value {
@ -49,11 +50,13 @@ impl fmt::Display for Value {
Value::Boolean (true) => write! (f, "true"),
Value::Float (x) => write! (f, "{:?}", x),
Value::Integer (x) => write! (f, "{}", x),
Value::RsFunc (x) => write! (f, "function: {:?}", x),
Value::String (s) => write! (f, "{}", s),
Value::Table (t) => write! (f, "table: {:?}", std::rc::Rc::as_ptr (t)),
Value::BogusArg (_) => write! (f, "BogusArg"),
Value::BogusClosure (_) => write! (f, "BogusClosure"),
Value::BogusEnv (_) => write! (f, "BogusEnv"),
Value::BogusPrint => write! (f, "BogusPrint"),
}
}
}
@ -94,34 +97,9 @@ impl From <f64> for Value {
}
}
impl From <usize> for Value {
fn from (x: usize) -> Self {
Self::Integer (i64::try_from (x).unwrap ())
}
}
impl From <Table> for Value {
fn from (x: Table) -> Self {
Self::Table (Rc::new (RefCell::new (x)))
}
}
impl FromIterator <(Value, Value)> for Value {
fn from_iter <I: IntoIterator <Item=(Value, Value)>> (i: I) -> Self {
let table = Table::from_iter (i);
Self::from (table)
}
}
impl FromIterator <(String, Value)> for Value {
fn from_iter <I: IntoIterator <Item=(String, Value)>> (i: I) -> Self {
Self::from_iter (i.into_iter ().map (|(s, v)| (Value::from (s), v)))
}
}
impl FromIterator <Value> for Value {
fn from_iter <I: IntoIterator <Item=Value>> (i: I) -> Self {
Self::from_iter ((1..).zip (i.into_iter ()).map (|(i, v)| (Value::from (i), v)))
Self::Table (x.into ())
}
}
@ -139,12 +117,14 @@ impl std::hash::Hash for Value {
Self::Float (x) => x.to_ne_bytes ().hash (state),
Self::Integer (x) => x.hash (state),
Self::RsFunc (x) => x.hash (state),
// TODO: Implement string interning so we don't hash the whole string here
Self::String (x) => x.hash (state),
Self::Table (x) => Rc::as_ptr (&x).hash (state),
Self::BogusArg (_) => panic! ("can't hash Bogus values"),
Self::BogusClosure (_) => panic! ("can't hash Bogus values"),
Self::BogusEnv (_) => panic! ("can't hash Bogus values"),
Self::BogusPrint => panic! ("can't hash Bogus values"),
}
}
}
@ -165,20 +145,6 @@ impl Value {
}
}
pub fn as_int (&self) -> Option <i64> {
match self {
Self::Integer (x) => Some (*x),
_ => None,
}
}
pub fn as_table (&self) -> Option <&Rc <RefCell <Table>>> {
match self {
Self::Table (t) => Some (t),
_ => None,
}
}
pub fn is_truthy (&self) -> bool {
// And this is something Lua does better than JS and Python.
@ -224,17 +190,6 @@ impl Table {
}
}
impl FromIterator <(Value, Value)> for Table {
fn from_iter<I: IntoIterator<Item = (Value, Value)>> (i: I) -> Self
{
let hash = i.into_iter ().collect ();
Self {
array: Default::default (),
hash,
}
}
}
#[cfg (test)]
mod tests {
use std::collections::HashMap;

View File

@ -1,11 +0,0 @@
for i = 1, 50 do
if i % 3 == 0 and i % 5 == 0 then
print (i, "FizzBuzz")
elseif i % 3 == 0 then
print (i, "Fizz")
elseif i % 5 == 0 then
print (i, "Buzz")
else
print (i)
end
end

View File

@ -1,4 +1,9 @@
print ("Hi!", 2)
print ()
print ("Hi!")
print ("You've _gotta_ admit this is **cool**!")
print (nil)
print (false)
print (true)
print (1993)
print (1993.00)
print "Hello."
local t = {}
print (t)