feat: mark and sweep environment

example/garbage-collection-01.rst

@@ -0,0 +1,4 @@
+{
+  fn garbage() {}
+}
+// garbage is out of scope and not reachable, so the environment should be removed

example/garbage-collection-02.rst

@@ -0,0 +1,9 @@
+fn higher_order(x) {
+  return y => x + y;
+}
+
+const add10 = higher_order(10);
+
+const result = add10(20);
+
+println(result); // 30

src/bytecode/src/builtin/conv/atoi.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const ATOI_SYM: &str = "atoi";
 
-pub fn atoi(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn atoi() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: ATOI_SYM.into(),
         prms: vec!["s".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/conv/float_to_int.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const FLOAT_TO_INT_SYM: &str = "float_to_int";
 
-pub fn float_to_int(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn float_to_int() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: FLOAT_TO_INT_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/conv/int_to_float.rs

@@ -1,18 +1,17 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
-
+use crate::{FnType, Value, W};
 pub const INT_TO_FLOAT_SYM: &str = "int_to_float";
 
-pub fn int_to_float(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn int_to_float() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: INT_TO_FLOAT_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/conv/itoa.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const ITOA_SYM: &str = "itoa";
 
-pub fn itoa(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn itoa() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: ITOA_SYM.into(),
         prms: vec!["i".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/abs.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{type_of, ByteCodeError, Environment, FnType, Value};
+use crate::{type_of, ByteCodeError, FnType, Value, W};
 
 pub const ABS_SYM: &str = "abs";
 
-pub fn abs(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn abs() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: ABS_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/cos.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const COS_SYM: &str = "cos";
 
-pub fn cos(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn cos() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: COS_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/log.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const LOG_SYM: &str = "log";
 
-pub fn log(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn log() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: LOG_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/max.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const MAX_SYM: &str = "max";
 
-pub fn max(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn max() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: MAX_SYM.into(),
         prms: vec!["v1".into(), "v2".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/min.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{type_of, ByteCodeError, Environment, FnType, Value};
+use crate::{type_of, ByteCodeError, FnType, Value, W};
 
 pub const MIN_SYM: &str = "min";
 
-pub fn min(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn min() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: MIN_SYM.into(),
         prms: vec!["v1".into(), "v2".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/pow.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const POW_SYM: &str = "pow";
 
-pub fn pow(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn pow() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: POW_SYM.into(),
         prms: vec!["base".into(), "exp".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/sin.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const SIN_SYM: &str = "sin";
 
-pub fn sin(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn sin() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: SIN_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/sqrt.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const SQRT_SYM: &str = "sqrt";
 
-pub fn sqrt(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn sqrt() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: SQRT_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/math/tan.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const TAN_SYM: &str = "tan";
 
-pub fn tan(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn tan() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: TAN_SYM.into(),
         prms: vec!["x".into()],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/semaphore/sem_create.rs

@@ -1,16 +1,16 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
-use crate::{Environment, FnType, Semaphore, Value};
+use crate::{FnType, Semaphore, Value, W};
 
 pub const SEM_CREATE_SYM: &str = "sem_create";
 
-pub fn sem_create(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn sem_create() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: SEM_CREATE_SYM.into(),
         prms: vec![],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/semaphore/sem_set.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Semaphore, Value};
+use crate::{FnType, Semaphore, Value, W};
 
 pub const SEM_SET_SYM: &str = "sem_set";
 
-pub fn sem_set(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn sem_set() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: SEM_SET_SYM.into(),
         prms: vec![],
         addr: 2,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }
 

src/bytecode/src/builtin/stdin/read_line.rs

@@ -1,18 +1,18 @@
-use std::{cell::RefCell, rc::Rc};
+use std::rc::Weak;
 
 use anyhow::Result;
 
-use crate::{Environment, FnType, Value};
+use crate::{FnType, Value, W};
 
 pub const READ_LINE_SYM: &str = "read_line";
 
-pub fn read_line(global_env: Rc<RefCell<Environment>>) -> Value {
+pub fn read_line() -> Value {
     Value::Closure {
         fn_type: FnType::Builtin,
         sym: READ_LINE_SYM.into(),
         prms: vec![],
         addr: 0,
-        env: global_env,
+        env: W(Weak::new()),
     }
 }