optimized native function calls

Cargo.toml

@@ -1,8 +1,4 @@
 [workspace]
-members = [
-	"talc-lang",
-	"talc-bin",
-	"talc-std",
-	"talc-macros",
-]
+members = ["talc-lang", "talc-bin", "talc-std", "talc-macros"]
 resolver = "2"
+

talc-lang/src/symbol.rs

@@ -1,11 +1,11 @@
-use std::{collections::HashMap, sync::{Arc, Mutex, OnceLock}};
+use std::{collections::HashMap, sync::{Mutex, OnceLock}};
 
 use lazy_static::lazy_static;
 
 #[derive(Default)]
 struct SymbolTable {
-	names: Vec<Arc<str>>,
-	values: HashMap<Arc<str>, Symbol>
+	names: Vec<&'static str>,
+	values: HashMap<&'static str, Symbol>
 }
 
 lazy_static! {
@@ -60,7 +60,7 @@ impl Symbol {
 	pub fn get(name: &str) -> Self {
 		let mut table = get_table().lock().expect("couldn't lock symbol table");
 
-		if let Some(sym) = table.values.get(name) {
+		if let Some(sym) = table.values.get(&name) {
 			return *sym
 		}
 
@@ -68,9 +68,9 @@ impl Symbol {
 		assert!(symno <= MAX_SYMBOL, "too many symbols");
 
 		let sym = Symbol(symno as u32);
-		let name: Arc<str> = name.into();
+		let name = String::leak(name.to_owned());
 
-		table.names.push(name.clone());
+		table.names.push(name);
 		table.values.insert(name, sym);
 
 		sym
@@ -99,7 +99,7 @@ impl Symbol {
 
 	/// # Panics
 	/// If the mutex storing the symbol table is poisoned
-	pub fn name(self) -> Arc<str> {
+	pub fn name(self) -> &'static str {
 		let table = get_table().lock().expect("couldn't lock symbol table");
 		table.names.get(self.0 as usize).cloned().expect("symbol does not exist")
 	}

talc-lang/src/vm.rs

@@ -404,9 +404,20 @@ impl Vm {
 				if let Value::NativeFunc(nf) = &args[0] {
 					let nf = nf.clone();
 
-					self.call_stack.push(std::mem::take(frame));
+					// safety: frame is restored immediately after
+					// function call ends
+					// ~25% performance improvement in for loop-heavy code
+					unsafe {
+						let f = std::ptr::read(frame);
+						self.call_stack.push(f);
+					}
+
 					let res = (nf.func)(self, args)?;
-					*frame = self.call_stack.pop().expect("no frame to pop");
+
+					unsafe {
+						let f = self.call_stack.pop().expect("no frame to pop");
+						std::ptr::write(frame, f);
+					}
 
 					self.stack.push(res);
 				} else if let Value::Function(func) = &args[0] {
@@ -414,10 +425,10 @@ impl Vm {
 					if self.call_stack.len() + 1 >= self.stack_max {
 						throw!(*SYM_CALL_STACK_OVERFLOW, "call stack overflow")
 					}
-					self.call_stack.push(std::mem::take(frame));
 
-					let func = func.clone();
-					*frame = CallFrame::new(func, args);
+					let new_frame = CallFrame::new(func.clone(), args);
+					let old_frame = std::mem::replace(frame, new_frame);
+					self.call_stack.push(old_frame);
 				} else {
 					unreachable!("already verified by calling get_call_type");
 				}

talc-std/src/iter.rs

@@ -6,12 +6,14 @@ use talc_macros::native_func;
 use crate::{unpack_args, unpack_varargs};
 
 pub fn load(vm: &mut Vm) {
+	// begin
 	vm.set_global_name("iter", iter().into());
 	vm.set_global_name("pairs", pairs().into());
 	vm.set_global_name("once", once().into());
 	vm.set_global_name("forever", forever().into());
 	vm.set_global_name("do_forever", forever().into());
 
+	// modify
 	vm.set_global_name("map", map().into());
 	vm.set_global_name("scan", scan().into());
 	vm.set_global_name("tee", tee().into());
@@ -20,15 +22,18 @@ pub fn load(vm: &mut Vm) {
 	vm.set_global_name("take", take().into());
 	vm.set_global_name("skip", skip().into());
 	vm.set_global_name("enumerate", enumerate().into());
+	vm.set_global_name("cycle", cycle().into());
+	vm.set_global_name("step", step().into());
+	vm.set_global_name("rev", rev().into());
+
+	// join
 	vm.set_global_name("zip", zip().into());
 	vm.set_global_name("alternate", alternate().into());
 	vm.set_global_name("intersperse", intersperse().into());
 	vm.set_global_name("cartprod", cartprod().into());
-	vm.set_global_name("cycle", cycle().into());
 	vm.set_global_name("chain", chain().into());
-	vm.set_global_name("step", step().into());
-	vm.set_global_name("rev", rev().into());
 
+	// end
 	vm.set_global_name("list", list().into());
 	vm.set_global_name("table", table().into());
 	vm.set_global_name("len", len().into());
@@ -288,6 +293,118 @@ pub fn enumerate(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
 	Ok(NativeFunc::new(Box::new(f), 0).into())
 }
 
+
+#[native_func(1)]
+pub fn cycle(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
+	let [_, iter] = unpack_args!(args);
+	let iter = iter.to_iter_function()?;
+
+	let record = RefCell::new((Vec::<Rc<RefCell<Value>>>::new(), false, 0));
+	let f = move |vm: &mut Vm, _| {
+		if record.borrow().1 {
+			let mut r = record.borrow_mut();
+			if r.0.is_empty() {
+				return Ok(Value::Nil)
+			}
+			let val = r.0[r.2].clone();
+			r.2 = (r.2 + 1) % r.0.len();
+			return Ok(val.into())
+		}
+		match vmcalliter!(vm; iter.clone())? {
+			Some(v) => {
+				record.borrow_mut().0.push(v.clone());
+				Ok(v.into())
+			},
+			None => {
+				let mut r = record.borrow_mut();
+				r.1 = true;
+				if r.0.is_empty() {
+					Ok(Value::Nil)
+				} else {
+					r.2 = (r.2 + 1) % r.0.len();
+					Ok(r.0[0].clone().into())
+				}
+			}
+		}
+	};
+
+	Ok(NativeFunc::new(Box::new(f), 0).into())
+}
+
+#[derive(Clone, Copy, Default)]
+enum Step {
+	First, Going, #[default] End,
+}
+
+#[native_func(2)]
+pub fn step(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
+	let [_, by, iter] = unpack_args!(args);
+	let iter = iter.to_iter_function()?;
+	let Value::Int(by) = by else {
+		throw!(*SYM_TYPE_ERROR, "step expected integer")
+	};
+	if by <= 0 {
+		throw!(*SYM_TYPE_ERROR, "step expected positive integer")
+	}
+
+	let state = RefCell::new(Step::First);
+	let f = move |vm: &mut Vm, _| match state.take() {
+		Step::First => {
+			match vmcalliter!(vm; iter.clone())? {
+				Some(x) => {
+					*state.borrow_mut() = Step::Going;
+					Ok(x.into())
+				},
+				None => Ok(Value::Nil),
+			}
+		},
+		Step::Going => {
+			for _ in 0..(by-1) {
+				if vmcall!(vm; iter.clone())? == Value::Nil {
+					return Ok(Value::Nil)
+				}
+			}
+			let Some(x) = vmcalliter!(vm; iter.clone())? else {
+				return Ok(Value::Nil)
+			};
+			*state.borrow_mut() = Step::Going;
+			Ok(x.into())
+		},
+		Step::End => Ok(Value::Nil),
+	};
+	Ok(NativeFunc::new(Box::new(f), 0).into())
+}
+
+#[native_func(1)]
+pub fn rev(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
+	let [_, iter] = unpack_args!(args);
+	let iter = iter.to_iter_function()?;
+
+	let lst = RefCell::new(None);
+	let f = move |vm: &mut Vm, _| {
+		if lst.borrow().is_none() {
+			let mut l = Vec::new();
+			while let Some(x) = vmcalliter!(vm; iter.clone())? {
+				l.push(cell_take(x))
+			}
+			l.reverse();
+			*lst.borrow_mut() = Some(l.into_iter());
+		}
+		match lst.borrow_mut().as_mut().unwrap().next() {
+			Some(v) => Ok(v.to_cell()),
+			None => Ok(Value::Nil),
+		}
+
+	};
+	Ok(NativeFunc::new(Box::new(f), 0).into())
+}
+
+
+//
+//  join
+//
+
+
 #[native_func(2..)]
 pub fn zip(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
 	let ([_, i1, i2], rest) = unpack_varargs!(args);
@@ -476,111 +593,6 @@ pub fn cartprod(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
 }
 
 
-#[native_func(1)]
-pub fn cycle(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
-	let [_, iter] = unpack_args!(args);
-	let iter = iter.to_iter_function()?;
-
-	let record = RefCell::new((Vec::<Rc<RefCell<Value>>>::new(), false, 0));
-	let f = move |vm: &mut Vm, _| {
-		if record.borrow().1 {
-			let mut r = record.borrow_mut();
-			if r.0.is_empty() {
-				return Ok(Value::Nil)
-			}
-			let val = r.0[r.2].clone();
-			r.2 = (r.2 + 1) % r.0.len();
-			return Ok(val.into())
-		}
-		match vmcalliter!(vm; iter.clone())? {
-			Some(v) => {
-				record.borrow_mut().0.push(v.clone());
-				Ok(v.into())
-			},
-			None => {
-				let mut r = record.borrow_mut();
-				r.1 = true;
-				if r.0.is_empty() {
-					Ok(Value::Nil)
-				} else {
-					r.2 = (r.2 + 1) % r.0.len();
-					Ok(r.0[0].clone().into())
-				}
-			}
-		}
-	};
-
-	Ok(NativeFunc::new(Box::new(f), 0).into())
-}
-
-#[derive(Clone, Copy, Default)]
-enum Step {
-	First, Going, #[default] End,
-}
-
-#[native_func(2)]
-pub fn step(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
-	let [_, by, iter] = unpack_args!(args);
-	let iter = iter.to_iter_function()?;
-	let Value::Int(by) = by else {
-		throw!(*SYM_TYPE_ERROR, "step expected integer")
-	};
-	if by <= 0 {
-		throw!(*SYM_TYPE_ERROR, "step expected positive integer")
-	}
-
-	let state = RefCell::new(Step::First);
-	let f = move |vm: &mut Vm, _| match state.take() {
-		Step::First => {
-			match vmcalliter!(vm; iter.clone())? {
-				Some(x) => {
-					*state.borrow_mut() = Step::Going;
-					Ok(x.into())
-				},
-				None => Ok(Value::Nil),
-			}
-		},
-		Step::Going => {
-			for _ in 0..(by-1) {
-				if vmcall!(vm; iter.clone())? == Value::Nil {
-					return Ok(Value::Nil)
-				}
-			}
-			let Some(x) = vmcalliter!(vm; iter.clone())? else {
-				return Ok(Value::Nil)
-			};
-			*state.borrow_mut() = Step::Going;
-			Ok(x.into())
-		},
-		Step::End => Ok(Value::Nil),
-	};
-	Ok(NativeFunc::new(Box::new(f), 0).into())
-}
-
-#[native_func(1)]
-pub fn rev(_: &mut Vm, args: Vec<Value>) -> Result<Value> {
-	let [_, iter] = unpack_args!(args);
-	let iter = iter.to_iter_function()?;
-
-	let lst = RefCell::new(None);
-	let f = move |vm: &mut Vm, _| {
-		if lst.borrow().is_none() {
-			let mut l = Vec::new();
-			while let Some(x) = vmcalliter!(vm; iter.clone())? {
-				l.push(cell_take(x))
-			}
-			l.reverse();
-			*lst.borrow_mut() = Some(l.into_iter());
-		}
-		match lst.borrow_mut().as_mut().unwrap().next() {
-			Some(v) => Ok(v.to_cell()),
-			None => Ok(Value::Nil),
-		}
-
-	};
-	Ok(NativeFunc::new(Box::new(f), 0).into())
-}
-
 
 //
 //  end iteration