refactoring, extensible types, basic file i/o

complexpr/Cargo.toml

@@ -9,3 +9,4 @@ num-rational = "0.4.1"
 num-traits = "0.2.15"
 strum = { version = "0.24.1", features = ["derive"] }
 paste = "1.0.9"
+lazy_static = "1.4.0"

complexpr/src/eval.rs

@@ -224,7 +224,7 @@ pub fn eval_expr(expr: &Expr, env: EnvRef) -> Result<Value, RuntimeError> {
             Ok(Value::Func(func))
         },
         Expr::StructInit { ty, args, .. } => {
-            let ty_val = eval_expr(&ty, env.clone())?;
+            let ty_val = eval_expr(ty, env.clone())?;
             let ty = match ty_val {
                 Value::Type(ty) => ty,
                 _ => return Err(format!("'{}' is not a type", ty_val.repr()).into())
@@ -294,7 +294,7 @@ pub fn eval_assignment(lhs: &Expr, rhs: &Expr, op: &Token, env: EnvRef) -> Resul
                 // plain assignment
                 let r = eval_expr(rhs, env.clone())?;
                 env.borrow_mut()
-                    .set(name.clone(), r.clone())
+                    .set(name, r.clone())
                     .map_err(|_| RuntimeError::new("Variable not declared before assignment", op.pos.clone()))?;
                 Ok(r)
             } else {
@@ -306,7 +306,7 @@ pub fn eval_assignment(lhs: &Expr, rhs: &Expr, op: &Token, env: EnvRef) -> Resul
 
                 let result = compound_assignment_inner(&prev_value, &r, op)?;
 
-                env.borrow_mut().set(name, result.clone()).expect("unreachable");
+                env.borrow_mut().set(name, result).expect("unreachable");
                 Ok(Value::Nil)
             }
         },
@@ -321,7 +321,7 @@ pub fn eval_assignment(lhs: &Expr, rhs: &Expr, op: &Token, env: EnvRef) -> Resul
                 let prev_value = l.index(&idx).map_err(|e| RuntimeError::new(e, pos.clone()))?;
                 let r = eval_expr(rhs, env)?;
                 let result = compound_assignment_inner(&prev_value, &r, op)?;
-                l.assign_index(&idx, result.clone()).map_err(|e| RuntimeError::new(e, pos.clone()))?;
+                l.assign_index(&idx, result).map_err(|e| RuntimeError::new(e, pos.clone()))?;
                 Ok(Value::Nil)
             }
         },
@@ -403,7 +403,7 @@ pub fn eval_boolean(lhs: &Expr, rhs: &Expr, op: &Token, env: EnvRef) -> Result<V
 
 fn mk_pipecolon_inner(f: Func, it: CIterator) -> Func {
     let it = RefCell::new(it);
-    return Func::BuiltinClosure{
+    Func::BuiltinClosure{
         arg_count: 0,
         func: Rc::new(move |_| {
             if let Some(next) = it.borrow_mut().next() {
@@ -417,7 +417,7 @@ fn mk_pipecolon_inner(f: Func, it: CIterator) -> Func {
 
 fn mk_pipequestion_inner(f: Func, it: CIterator) -> Func {
     let it = RefCell::new(it);
-    return Func::BuiltinClosure {
+    Func::BuiltinClosure {
         arg_count: 0,
         func: Rc::new(move |_| {
             loop {

complexpr/src/parser.rs

@@ -410,8 +410,8 @@ impl Parser {
             };
             Ok(Expr::Range { 
                 start: Box::new(start), 
-                end: end.map(|x| Box::new(x)), 
-                step: step.map(|x| Box::new(x)), 
+                end: end.map(Box::new),
+                step: step.map(Box::new),
                 incl 
             })
         } else {

complexpr/src/stdlib/io.rs

@@ -1,21 +1,24 @@
-use std::io::Write;
+use std::{io::{Write, Read}, fs::{OpenOptions, File}, rc::Rc, cell::RefCell, fmt};
 
-use crate::{env::Environment, declare_fn, value::Value, RuntimeError};
+use crate::{env::Environment, declare_fn, value::{Value, Native, TypeData}, RuntimeError};
 
 pub fn load(env: &mut Environment) {
     declare_fn!(env, print, 1);
     declare_fn!(env, println, 1);
     declare_fn!(env, input, 0);
+    declare_fn!(env, open, 1);
+    declare_fn!(env, close, 1);
+    declare_fn!(env, read, 1);
 }
 
 fn fn_print(args: Vec<Value>) -> Result<Value, RuntimeError> {
-    print!("{}", args[0].to_string());
+    print!("{}", args[0]);
     std::io::stdout().flush().map_err(|e| e.to_string())?;
     Ok(Value::Nil)
 }
 
 fn fn_println(args: Vec<Value>) -> Result<Value, RuntimeError> {
-    println!("{}", args[0].to_string());
+    println!("{}", args[0]);
     Ok(Value::Nil)
 }
 
@@ -28,3 +31,88 @@ fn fn_input(_: Vec<Value>) -> Result<Value, RuntimeError> {
     }
     Ok(Value::from(buffer))
 }
+
+struct FileBox {
+    f: Option<File>
+}
+
+lazy_static::lazy_static! {
+    static ref FILE_TYPE_ID: usize = crate::value::generate_type_id();
+}
+thread_local!(static FILE_TYPE_NAME: Rc<str> = Rc::from("File"));
+
+impl Native for FileBox {
+    fn as_any(&self) -> &dyn std::any::Any {
+        self
+    }
+
+    fn as_any_mut(&mut self) -> &mut dyn std::any::Any {
+        self
+    }
+
+    fn get_type(&self) -> crate::value::Type {
+        crate::value::Type { name: FILE_TYPE_NAME.with(Rc::clone), id: *FILE_TYPE_ID, typedata: TypeData::None }
+        
+    }
+}
+
+impl fmt::Debug for FileBox {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self, f)
+    }
+}
+
+impl fmt::Display for FileBox {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "<file {:?}>", self.f)
+    }
+}
+
+fn fn_open(args: Vec<Value>) -> Result<Value, RuntimeError> {
+    let fname = match &args[0] {
+        Value::String(s) => s,
+        _ => return Err(format!("Expected filename, got {}", args[0]).into())
+    };
+    let f = match OpenOptions::new().read(true).open(fname.as_ref()) {
+        Ok(f) => f,
+        Err(e) => return Err(format!("Could not open file '{}': {}", fname, e).into())
+    };
+    Ok(Value::Native(Rc::new(RefCell::new(FileBox { f: Some(f) }))))
+}
+
+fn fn_close(args: Vec<Value>) -> Result<Value, RuntimeError> {
+    match &args[0] {
+        Value::Native(s) => {
+            let mut bs = s.borrow_mut();
+            let f: &mut FileBox = match bs.as_any_mut().downcast_mut() {
+                Some(f) => f,
+                None => return Err(format!("Expected a file, got {}", args[0]).into())
+            };
+            drop(f.f.take());
+            Ok(Value::Nil)
+        },
+        _ => return Err(format!("Expected a file, got {}", args[0]).into())
+    }
+}
+
+fn fn_read(args: Vec<Value>) -> Result<Value, RuntimeError> {
+    match &args[0] {
+        Value::Native(s) => {
+            let mut bs = s.borrow_mut();
+            let f: &mut FileBox = match bs.as_any_mut().downcast_mut() {
+                Some(f) => f,
+                None => return Err(format!("Expected a file, got {}", args[0]).into())
+            };
+            if let Some(file) = &mut f.f {
+                let mut buf = String::new();
+                match file.read_to_string(&mut buf) {
+                    Ok(_) => return Ok(Value::from(buf)),
+                    Err(e) => return Err(format!("Error reading file {}: {}", f, e).into())
+                }
+            } else {
+                Err("Attempt to read file that has been closed".into())
+            }
+        },
+        _ => return Err(format!("Expected a file, got {}", args[0]).into())
+    }
+}

complexpr/src/stdlib/math.rs

@@ -56,9 +56,9 @@ fn try_into_floaty(v: &Value, name: &'static str) -> Result<Floaty, String> {
     match v {
         Value::Int(n) => Ok((*n as f64).into()),
         Value::Float(f) => Ok((*f).into()),
-        Value::Rational(r) => Ok((r.to_f64().ok_or_else(|| "Could not convert rational to float")?).into()),
+        Value::Rational(r) => Ok((r.to_f64().ok_or("Could not convert rational to float")?).into()),
         Value::Complex(z) => Ok((*z).into()),
-        _ => Err(format!("Argument to {} must be numeric", name).into())
+        _ => Err(format!("Argument to {} must be numeric", name))
     }
 }
 

complexpr/src/stdlib/mod.rs

@@ -2,9 +2,9 @@ pub mod io;
 pub mod iter;
 pub mod math;
 
-use std::time::{SystemTime, UNIX_EPOCH};
+use std::{time::{SystemTime, UNIX_EPOCH}, rc::Rc, cell::RefCell};
 
-use crate::{value::Value, RuntimeError, env::Environment};
+use crate::{value::{Value, func::Func}, RuntimeError, env::Environment};
 
 #[macro_export]
 macro_rules! declare_fn {
@@ -28,6 +28,7 @@ pub fn load(env: &mut Environment) {
     declare_fn!(env, chr, 1); 
     declare_fn!(env, has, 2); 
     declare_fn!(env, len, 1); 
+    declare_fn!(env, args, 0); 
     declare_fn!(env, time, 0); 
     declare_fn!(env, list, 1);
     declare_fn!(env, push, 2);
@@ -99,6 +100,21 @@ fn fn_has(args: Vec<Value>) -> Result<Value, RuntimeError> {
     }
 }
 
+fn fn_args(_: Vec<Value>) -> Result<Value, RuntimeError> {
+    let mut args = std::env::args();
+    args.next();
+    let args = RefCell::new(args);
+    Ok(Value::Func(Func::BuiltinClosure {
+        arg_count: 0,
+        func: Rc::new(move |_| {
+            match args.borrow_mut().next() {
+                Some(s) => Ok(Value::from(s)),
+                None => Ok(Value::Nil)
+            }
+        })
+    }))
+}
+
 fn fn_time(_: Vec<Value>) -> Result<Value, RuntimeError> {
     let time = SystemTime::now().duration_since(UNIX_EPOCH).map_err(|e| e.to_string())?;
     Ok(Value::from(time.as_secs_f64()))
@@ -122,7 +138,7 @@ fn fn_push(args: Vec<Value>) -> Result<Value, RuntimeError> {
 
 fn fn_pop(args: Vec<Value>) -> Result<Value, RuntimeError> {
     if let Value::List(l) = &args[0] {
-        l.as_ref().borrow_mut().pop().ok_or("Pop on empty list".into())
+        l.as_ref().borrow_mut().pop().ok_or_else(|| "Pop on empty list".into())
     } else{
         Err("First argument to pop must be a list".into())
     }

complexpr/src/value/mod.rs

@@ -1,4 +1,4 @@
-use std::{rc::Rc, collections::HashMap, ops::*, cmp::Ordering, cell::RefCell, hash::Hash, sync::atomic::{AtomicUsize, self}};
+use std::{rc::Rc, collections::HashMap, ops::*, cmp::Ordering, cell::RefCell, hash::Hash, sync::atomic::{AtomicUsize, self}, fmt::{self, Write}, any::Any};
 
 use num_traits::{Zero, ToPrimitive, Pow};
 use strum::{EnumCount, EnumDiscriminants, EnumIter, IntoEnumIterator, AsRefStr};
@@ -10,6 +10,12 @@ pub mod func;
 pub type Rational = num_rational::Ratio<i64>;
 pub type Complex = num_complex::Complex64;
 
+pub trait Native: Any + std::fmt::Debug + std::fmt::Display {
+    fn as_any(&self) -> &dyn Any;
+    fn as_any_mut(&mut self) -> &mut dyn Any;
+    fn get_type(&self) -> Type;
+}
+
 static TYPE_COUNTER: AtomicUsize = AtomicUsize::new(Value::COUNT);
 
 #[derive(Clone, Debug)]
@@ -33,6 +39,10 @@ impl PartialEq for Type {
 
 impl Eq for Type {}
 
+pub fn generate_type_id() -> usize {
+    TYPE_COUNTER.fetch_add(1, atomic::Ordering::Relaxed)
+}
+
 pub fn generate_struct_type(name: Rc<str>, fields: Vec<String>) -> Type {
     Type { 
         name, 
@@ -55,21 +65,25 @@ pub fn generate_builtin_types() -> Vec<Type> {
 
 fn fmt_list(list: &Vec<Value>) -> String {
     let mut result: String = "[".into();
-    for v in list {
-        result += &(v.repr() + ", ");
+    if list.len() > 0 {
+        for v in list {
+            result += &(v.repr() + ", ");
+        }
+        result.pop();
+        result.pop();
     }
-    result.pop();
-    result.pop();
     result + "]"
 }
 
 fn fmt_map(map: &HashMap<Value, Value>) -> String {
     let mut result: String = "{".into();
-    for (k, v) in map {
-        result += &(k.repr() + ": " + &v.repr() + ", ");
+    if map.len() > 0 {
+        for (k, v) in map {
+            result += &(k.repr() + ": " + &v.repr() + ", ");
+        }
+        result.pop();
+        result.pop();
     }
-    result.pop();
-    result.pop();
     result + "}"
 }
 
@@ -140,6 +154,7 @@ pub enum Value {
     Map(Rc<RefCell<HashMap<Value,Value>>>),
     Func(Func),
     Struct(CxprStruct),
+    Native(Rc<RefCell<dyn Native>>),
 }
 
 impl Value {
@@ -150,9 +165,9 @@ impl Value {
             Float(f) => *f != 0.0,
             Complex(z) => !z.is_zero(),
             Rational(r) => !r.is_zero(),
-            String(s) => !s.len() == 0,
-            List(l) => !l.borrow().len() == 0,
-            Map(m) => !m.borrow().len() == 0,
+            String(s) => s.len() != 0,
+            List(l) => l.borrow().len() != 0,
+            Map(m) => m.borrow().len() != 0,
             Char(c) => *c != '\0',
             _ => true
         }
@@ -180,35 +195,6 @@ impl Value {
         }
     }
 
-    pub fn to_string(&self) -> String {
-        match self {
-            Self::Nil => "nil".into(),
-            Self::Bool(b) => b.to_string(),
-            Self::Int(n) => n.to_string(),
-            Self::Float(f) => f.to_string(),
-            Self::Rational(r) => r.to_string(),
-            Self::Complex(z) => z.to_string(),
-            Self::Char(c) => c.to_string(),
-            Self::String(s) => s.as_ref().to_owned(),
-            Self::List(l) => fmt_list(&l.borrow()),
-            Self::Map(m) => fmt_map(&m.borrow()),
-            Self::Type(t) => format!("<type {}>", t.name),
-            Self::Func(Func::Builtin { name, func, .. }) => format!("<builtin fn {} at {:?}>", name, *func as *const ()),
-            Self::Func(Func::BuiltinClosure { .. }) => format!("<builtin anonymous fn>"),
-            Self::Func(f @ Func::Partial { .. }) => match f.name() {
-                Some(name) => format!("<partial of fn {}>", name),
-                None => "<partial of anonymous fn>".into(),
-            }
-            Self::Func(Func::Func { name, .. }) => match name {
-                Some(name) => format!("<fn {}>", name),
-                None => "<anonymous fn>".into(),
-            },
-            Self::Struct(CxprStruct { ty, data }) 
-                => format!("{} {{ {} }}", ty.name, 
-                    data.borrow().iter().map(|(k, v)| format!("{}: {}", k, v.repr()))
-                        .collect::<Vec<String>>().join(", "))
-        }
-    }
     
     pub fn repr(&self) -> String {
         match self {
@@ -290,8 +276,10 @@ impl Value {
     
     pub fn get_type(&self) -> Type {
         let discr = ValueDiscriminants::from(self);
-        if let Self::Struct(_) = self {
-            todo!()
+        if let Self::Struct(s) = self {
+            s.ty.clone()
+        } else if let Self::Native(n) = self {
+            n.borrow().get_type()
         } else {
             Type {
                 name: Rc::from(discr.as_ref()),
@@ -302,6 +290,39 @@ impl Value {
     }
 }
 
+impl fmt::Display for Value {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Nil => f.write_str("nil"),
+            Self::Bool(b) => f.write_str(&b.to_string()),
+            Self::Int(n) => f.write_str(&n.to_string()),
+            Self::Float(x) => f.write_str(&x.to_string()),
+            Self::Rational(r) => f.write_str(&r.to_string()),
+            Self::Complex(z) => f.write_str(&z.to_string()),
+            Self::Char(c) => f.write_char(*c),
+            Self::String(s) => f.write_str(s.as_ref()),
+            Self::List(l) => f.write_str(&fmt_list(&l.borrow())),
+            Self::Map(m) => f.write_str(&fmt_map(&m.borrow())),
+            Self::Type(t) => write!(f, "<type {}>", t.name),
+            Self::Func(Func::Builtin { name, func, .. }) => write!(f, "<builtin fn {} at {:?}>", name, *func as *const ()),
+            Self::Func(Func::BuiltinClosure { .. }) => f.write_str("<builtin anonymous fn>"),
+            Self::Func(func @ Func::Partial { .. }) => match func.name() {
+                Some(name) => write!(f, "<partial of fn {}>", name),
+                None => f.write_str("<partial of anonymous fn>"),
+            }
+            Self::Func(Func::Func { name, .. }) => match name {
+                Some(name) => write!(f, "<fn {}>", name),
+                None => f.write_str("<anonymous fn>"),
+            },
+            Self::Struct(CxprStruct { ty, data }) 
+                => write!(f, "{} {{ {} }}", ty.name, 
+                    data.borrow().iter().map(|(k, v)| format!("{}: {}", k, v.repr()))
+                        .collect::<Vec<String>>().join(", ")),
+            Self::Native(x) => f.write_str(&x.borrow().to_string()),
+        }
+    }
+}
+
 #[allow(clippy::ptr_eq)] // provided fix does not work
 impl PartialEq for Value {
     fn eq(&self, other: &Self) -> bool {
@@ -415,6 +436,7 @@ impl Hash for Value {
             Self::Map(_) => todo!(),
             Self::Func(f) => f.hash(state),
             Self::Struct(_) => todo!(),
+            Self::Native(_) => todo!(),
 
         }
     }