commit cf59d6f88c6e25ef76c364c9abfc4f3e478ac805
Author: voidNUL <50534996+Xterminate1818@users.noreply.github.com>
Date:   Sat Feb 24 23:00:45 2024 -0600

    initial

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..5dec02f
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "forte"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/src/asm.rs b/src/asm.rs
new file mode 100644
index 0000000..ccc64e6
--- /dev/null
+++ b/src/asm.rs
@@ -0,0 +1,84 @@
+use crate::{OpKind, Word};
+use log::*;
+
+/// Assembler
+
+#[derive(Debug, Copy, Clone)]
+pub enum AsmError {
+  ExpectedNum,
+  InvalidOp,
+}
+
+fn parse_num(input: &str) -> Result<Word, AsmError> {
+  debug!("Parsing {} as number", input);
+  if let Ok(n) = input.parse::<Word>() {
+    return Ok(n);
+  }
+  if let Ok(n) = Word::from_str_radix(input.trim_start_matches("0x"), 16) {
+    return Ok(n);
+  }
+  Err(AsmError::ExpectedNum)
+}
+
+fn parse_op(input: &str) -> Result<Word, AsmError> {
+  debug!("Parsing {} as opcode", input);
+  let op = match input {
+    "push" => OpKind::Push,
+    "pop" => OpKind::Pop,
+    "dup" => OpKind::Dup,
+    "add" => OpKind::Add,
+    "dif" => OpKind::Dif,
+    "mul" => OpKind::Mul,
+    "div" => OpKind::Div,
+    "rem" => OpKind::Rem,
+    "and" => OpKind::And,
+    "or" => OpKind::Or,
+    "xor" => OpKind::Xor,
+    "shr" => OpKind::Shr,
+    "shl" => OpKind::Shl,
+    "beq" => OpKind::Beq,
+    "bne" => OpKind::Bne,
+    "bgt" => OpKind::Bgt,
+    "blt" => OpKind::Blt,
+    "fun" => OpKind::Fun,
+    "call" => OpKind::Call,
+    "ret" => OpKind::Ret,
+    "loop" => OpKind::Loop,
+    "iter" => OpKind::Iter,
+    "exe" => OpKind::Exe,
+    "sto" => OpKind::Sto,
+    "lod" => OpKind::Lod,
+    "len" => OpKind::Len,
+    _ => return Err(AsmError::InvalidOp),
+  };
+  Ok(op as Word)
+}
+
+pub fn assemble(input: &str) -> Result<Vec<Word>, AsmError> {
+  let mut last: Option<Word> = None;
+
+  let split = input.split_whitespace();
+  let mut output = Vec::with_capacity(split.size_hint().0);
+  for part in split {
+    // If just parsed op, next should be num
+    if last.is_some() {
+      let num = parse_num(part)?;
+      let op = last.take().unwrap();
+      let word = (op << 64) | num;
+      output.push(word);
+    }
+    // Otherwise, could be op or num
+    else {
+      if let Ok(op) = parse_op(part) {
+        last = Some(op);
+      } else {
+        output.push(parse_num(part)?);
+      }
+    }
+  }
+  if last.is_some() {
+    Err(AsmError::ExpectedNum)
+  } else {
+    Ok(output)
+  }
+}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..5feced3
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,407 @@
+mod asm;
+mod op;
+mod util;
+
+use op::*;
+use util::*;
+
+use log::*;
+pub type Byte = u32;
+pub type Word = u128;
+
+#[derive(Debug, Clone, Copy)]
+pub enum Phase {
+  Warmup,
+  Recital,
+}
+
+pub struct Machine {
+  ip: Word,
+  ebp: Word,
+  phase: Phase,
+  pub cstack: Vec<Word>,
+  pub pstack: Vec<Word>,
+  pub fstack: Vec<Word>,
+  pub instructions: Vec<Word>,
+  pub mem: Vec<Word>,
+}
+
+impl Machine {
+  pub fn new() -> Self {
+    Self {
+      ip: 0,
+      ebp: 0,
+      phase: Phase::Warmup,
+      cstack: vec![],
+      pstack: vec![],
+      fstack: vec![],
+      instructions: vec![],
+      mem: vec![0; 1024],
+    }
+  }
+
+  pub fn read(&mut self, src: Vec<u128>) {
+    self.instructions = src;
+  }
+
+  fn memset(&mut self, address: Word, val: Word) -> CResult {
+    let address: usize = match address.try_into() {
+      Ok(a) => a,
+      Err(_) => return Err(Error::WriteOob),
+    };
+    let reference = self.mem.get_mut(address).ok_or(Error::WriteOob)?;
+    *reference = val;
+    Ok(())
+  }
+
+  fn memget(&mut self, address: Word) -> Result<Word, Error> {
+    let address: usize = match address.try_into() {
+      Ok(a) => a,
+      Err(_) => return Err(Error::WriteOob),
+    };
+    self.mem.get(address).ok_or(Error::WriteOob).copied()
+  }
+
+  fn c_pop(&mut self) -> Result<Word, Error> {
+    match self.cstack.pop() {
+      Some(i) => Ok(i),
+      None => Err(Error::StackUnderflow),
+    }
+  }
+
+  fn p_pop(&mut self) -> Result<Word, Error> {
+    match self.pstack.pop() {
+      Some(i) => Ok(i),
+      None => Err(Error::StackUnderflow),
+    }
+  }
+
+  fn p_peak(&mut self) -> Result<Word, Error> {
+    match self.pstack.last() {
+      Some(i) => Ok(*i),
+      None => Err(Error::StackUnderflow),
+    }
+  }
+
+  fn call(&mut self, address: Word) -> CResult {
+    let address: usize = address.try_into().map_err(|_| Error::BadCall)?;
+    let address = *self.fstack.get(address).ok_or(Error::BadCall)?;
+
+    self.cstack.push(self.ip);
+    self.cstack.push(self.cstack.len() as Word);
+    if address >= self.instructions.len() as Word {
+      return Err(Error::BadCall);
+    }
+    self.ip = address;
+    Ok(())
+  }
+
+  fn _return(&mut self) -> CResult {
+    let ebp = self.c_pop()?;
+    let ip = self.c_pop()?;
+    self.ip = ip;
+    self.ebp = ebp;
+    Ok(())
+  }
+
+  pub fn step(&mut self) -> CResult {
+    let word = self
+      .instructions
+      .get(self.ip as usize)
+      .expect("Ran out of instructions");
+    let instr: Op = match word.try_into() {
+      Ok(i) => i,
+      Err(_) => {
+        error!("Invalid opcode: {:#x}", word);
+        panic!()
+      },
+    };
+    debug!(
+      "[{:?}]{}: {:?} {}",
+      self.phase, self.ip, instr.kind, instr.var
+    );
+    self.ip += 1;
+    match self.phase {
+      Phase::Warmup => self.step_warmup(instr),
+      Phase::Recital => self.step_recital(instr),
+    }
+  }
+
+  pub fn step_recital(&mut self, instr: Op) -> CResult {
+    match instr.kind {
+      OpKind::Push => {
+        for _ in 0..instr.var {
+          let num = match self.instructions.get(self.ip as usize) {
+            Some(n) => n,
+            None => return Err(Error::StackUnderflow),
+          };
+          debug!("{}: _ {}", self.ip, num);
+          self.pstack.push(*num);
+          self.ip += 1;
+        }
+      },
+      OpKind::Pop => {
+        for _ in 0..instr.var {
+          self.p_pop()?;
+        }
+      },
+      OpKind::Dup => {
+        let d = self.p_peak().unwrap_or(0);
+        for _ in 0..instr.var {
+          self.pstack.push(d);
+        }
+      },
+      OpKind::Add => {
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(a.saturating_add(b));
+        }
+      },
+      OpKind::Dif => {
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(abs_sub(a, b));
+        }
+      },
+      OpKind::Mul => {
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(a.saturating_mul(b));
+        }
+      },
+      OpKind::Div => {
+        if instr.var == 0 {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(b.checked_div(a).unwrap_or(Word::MAX));
+        } else {
+          let numerator = self.p_pop()?;
+          self.pstack.push(
+            numerator
+              .checked_div(instr.var as Word)
+              .unwrap_or(Word::MAX),
+          )
+        }
+      },
+      OpKind::Rem => {
+        if instr.var == 0 {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self
+            .pstack
+            .push(b.checked_rem_euclid(a).unwrap_or(Word::MAX));
+        } else {
+          let numerator = self.p_pop()?;
+          self.pstack.push(
+            numerator
+              .checked_rem_euclid(instr.var as Word)
+              .unwrap_or(Word::MAX),
+          )
+        }
+      },
+      OpKind::And => {
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(a & b);
+        }
+      },
+      OpKind::Or => {
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(a | b);
+        }
+      },
+      OpKind::Xor => {
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(a ^ b);
+        }
+      },
+      OpKind::Shl => {
+        if instr.var == 0 {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(b << a);
+        } else {
+          let top = self.p_pop()?;
+          self.pstack.push(top << instr.var as Word);
+        }
+      },
+      OpKind::Shr => {
+        if instr.var == 0 {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          self.pstack.push(b >> a);
+        } else {
+          let top = self.p_pop()?;
+          self.pstack.push(top >> instr.var as Word);
+        }
+      },
+      OpKind::Beq => {
+        let mut should_branch = false;
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          should_branch |= a != b;
+          self.pstack.push(a);
+        }
+        // Remove extraneous
+        self.p_pop()?;
+        if should_branch {
+          self.ip += 1;
+          self.call(instr.var as Word)?;
+        }
+      },
+      OpKind::Bne => {
+        let mut should_branch = false;
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          should_branch |= a == b;
+          self.pstack.push(a);
+        }
+        // Remove extraneous
+        self.p_pop()?;
+        if should_branch {
+          self.ip += 1;
+          self.call(instr.var as Word)?;
+        }
+      },
+
+      OpKind::Bgt => {
+        let mut should_branch = false;
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          should_branch |= a <= b;
+          self.pstack.push(a);
+        }
+        // Remove extraneous
+        self.p_pop()?;
+        if should_branch {
+          self.ip += 1;
+          self.call(instr.var as Word)?;
+        }
+      },
+
+      OpKind::Blt => {
+        let mut should_branch = false;
+        for _ in 0..instr.var {
+          let a = self.p_pop()?;
+          let b = self.p_pop()?;
+          should_branch |= a <= b;
+          self.pstack.push(a);
+        }
+        // Remove extraneous
+        self.p_pop()?;
+        if should_branch {
+          self.ip += 1;
+          self.call(instr.var as Word)?;
+        }
+      },
+      OpKind::Fun => {
+        // Ignore during execution
+      },
+      OpKind::Call => {
+        self.call(instr.var as Word)?;
+      },
+      OpKind::Ret => {
+        self._return()?;
+      },
+
+      OpKind::Loop => {
+        self.cstack.push(self.ip);
+        self.cstack.push(instr.var as Word);
+      },
+
+      OpKind::Iter => {
+        let counter = self.c_pop()?;
+        let address = self.c_pop()?;
+        if counter.saturating_sub(1) != 0 {
+          self.cstack.push(address);
+          self.cstack.push(counter - 1);
+        }
+      },
+      OpKind::Exe => {
+        // Ignore in execution
+        self.phase = Phase::Recital;
+        // TODO: Maybe break program here?
+      },
+
+      OpKind::Sto => {
+        let word = self.p_pop()?;
+        self.memset(instr.var as Word, word)?;
+      },
+
+      OpKind::Lod => {
+        let word = self.memget(instr.var as Word)?;
+        self.pstack.push(word);
+      },
+      OpKind::Len => {
+        self.pstack.push(self.pstack.len() as Word - self.ebp);
+      },
+      _ => {},
+    };
+    debug!("{:?}", self.pstack);
+    Ok(())
+  }
+
+  pub fn step_warmup(&mut self, instr: Op) -> CResult {
+    match instr.kind {
+      OpKind::Fun => self.fstack.push(self.ip),
+      OpKind::Exe => {
+        self.phase = Phase::Recital;
+        self.ip = match self.fstack.last() {
+          Some(i) => *i,
+          None => return Err(Error::StackUnderflow),
+        }
+      },
+      _ => {},
+    }
+    Ok(())
+  }
+
+  pub fn steps(&mut self, n: usize) -> CResult {
+    for _ in 0..n {
+      self.step()?;
+    }
+    Ok(())
+  }
+}
+
+fn main() {
+  flexi_logger::Logger::try_with_str("rh24")
+    .unwrap()
+    .start()
+    .unwrap();
+
+  let mut m = Machine::new();
+  // let program = vec![
+  //   //
+  //   Op::new(OpKind::Fun, 0),
+  //   Op::new(OpKind::Push, 2),
+  //   15,
+  //   30,
+  //   Op::new(OpKind::Dif, 1),
+  //   Op::new(OpKind::Ret, 0),
+  //   Op::new(OpKind::Fun, 0),
+  //   Op::new(OpKind::Push, 2),
+  //   16,
+  //   4,
+  //   Op::new(OpKind::Dif, 1),
+  //   Op::new(OpKind::Call, 0),
+  //   Op::new(OpKind::Add, 1),
+  //   Op::new(OpKind::Exe, 0),
+  // ];
+  let program = include_str!("./../demo.asm");
+  let program = asm::assemble(program).unwrap();
+  m.read(program);
+  m.steps(32).unwrap();
+  println!("RESULT = {:?}", m.pstack);
+}
diff --git a/src/op.rs b/src/op.rs
new file mode 100644
index 0000000..9282889
--- /dev/null
+++ b/src/op.rs
@@ -0,0 +1,112 @@
+use crate::Word;
+
+#[derive(Clone, Copy, Debug)]
+#[repr(u64)]
+pub enum OpKind {
+  // P-Stack
+  Push,
+  Pop,
+  Dup,
+  // Math
+  Add,
+  Dif,
+  Mul,
+  Div,
+  Rem,
+  // Bool
+  And,
+  Or,
+  Xor,
+  Shr,
+  Shl,
+  // C-Stack
+  Beq,
+  Bne,
+  Bgt,
+  Blt,
+  // I-Stack
+  /// Begin function def
+  Fun,
+  Call,
+  Ret,
+  /// Begin subroutine
+  Loop,
+  /// Iterate the loop
+  Iter,
+  /// Break loop early
+  Exe,
+  // Memory
+  Sto,
+  Lod,
+  // Misc
+  // Length of the stack currently
+  Len,
+
+  LAST,
+}
+
+impl TryFrom<u64> for OpKind {
+  type Error = ();
+
+  fn try_from(value: u64) -> Result<Self, Self::Error> {
+    Ok(match value {
+      0 => Self::Push,
+      1 => Self::Pop,
+      2 => Self::Dup,
+      3 => Self::Add,
+      4 => Self::Dif,
+      5 => Self::Mul,
+      6 => Self::Div,
+      7 => Self::Rem,
+      8 => Self::And,
+      9 => Self::Or,
+      10 => Self::Xor,
+      11 => Self::Shr,
+      12 => Self::Shl,
+      13 => Self::Beq,
+      14 => Self::Bne,
+      15 => Self::Bgt,
+      16 => Self::Blt,
+      17 => Self::Fun,
+      18 => Self::Call,
+      19 => Self::Ret,
+      20 => Self::Loop,
+      21 => Self::Iter,
+      22 => Self::Exe,
+      23 => Self::Sto,
+      24 => Self::Lod,
+      25 => Self::Len,
+      _ => return Err(()),
+    })
+  }
+}
+
+#[derive(Clone, Debug)]
+pub struct Op {
+  pub op: u64,
+  pub kind: OpKind,
+  pub var: u64,
+}
+
+impl Op {
+  pub fn new(kind: OpKind, var: u64) -> Word {
+    let top = (kind as u64 as u128) << 64;
+    let bottom = var as u128;
+    top | bottom
+  }
+}
+
+impl TryFrom<&u128> for Op {
+  type Error = ();
+
+  fn try_from(value: &u128) -> Result<Self, Self::Error> {
+    let top = value >> 64;
+    let bottom = value & 0xFFFF_FFFF;
+    let kind: OpKind = (top as u64).try_into()?;
+    Ok(Self {
+      kind,
+      op: top as u64,
+      var: bottom as u64,
+    })
+  }
+}
diff --git a/src/util.rs b/src/util.rs
new file mode 100644
index 0000000..fce496c
--- /dev/null
+++ b/src/util.rs
@@ -0,0 +1,43 @@
+use std::fmt::{Debug, Display};
+
+use crate::{op::Op, Word};
+
+pub fn abs_sub(a: Word, b: Word) -> Word {
+  let max = u128::max(a, b);
+  let min = u128::min(a, b);
+  max - min
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum Error {
+  StackOverflow,
+  StackUnderflow,
+  StackUnbalanced,
+  WriteOob,
+  ReadOob,
+  BadCall,
+  NoExec,
+  EndReached,
+}
+
+impl Display for Error {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    match self {
+      Self::StackOverflow => write!(f, "Stack Overflow"),
+      Self::StackUnderflow => write!(f, "Stack Underflow"),
+      Self::StackUnbalanced => write!(f, "Stack Unbalanced"),
+      Self::WriteOob => write!(f, "Memory write out of bounds"),
+      Self::ReadOob => write!(f, "Memory read out of bounds"),
+      Self::BadCall => {
+        write!(f, "Attempted to call function which does not exist")
+      },
+      Self::NoExec => write!(
+        f,
+        "No exec instruction found. Are you trying to execute a library?"
+      ),
+      Self::EndReached => write!(f, "Successfully terminated"),
+    }
+  }
+}
+
+pub type CResult = Result<(), Error>;