get base functions working

src/base.rs

@@ -1,28 +1,18 @@
+// Solution to the #[derive(Clone)] problem: https://stackoverflow.com/questions/27883509/can-you-clone-a-closure
 use crate::value::*;
 use crate::vm::*;
 use imbl::*;
-use std::cell::RefCell;
 use std::fmt;
-use std::rc::Rc;
 
+type LResult<'src> = Result<Value<'src>, LudusError>;
+
+#[derive(Clone, Debug)]
 pub enum Base<'src> {
-    Unary(
-        &'src str,
-        Box<dyn std::ops::Fn(Value<'src>) -> Result<Value<'src>, LudusError>>,
-    ),
-    Binary(
-        &'src str,
-        Box<dyn std::ops::Fn(Value<'src>, Value<'src>) -> Result<Value<'src>, LudusError>>,
-    ),
+    Unary(&'src str, fn(&Value<'src>) -> LResult<'src>),
+    Binary(&'src str, fn(&Value<'src>, &Value<'src>) -> LResult<'src>),
     Ternary(
         &'src str,
-        Box<
-            dyn std::ops::Fn(
-                Value<'src>,
-                Value<'src>,
-                Value<'src>,
-            ) -> Result<Value<'src>, LudusError>,
-        >,
+        fn(&Value<'src>, &Value<'src>, &Value<'src>) -> LResult<'src>,
     ),
 }
 
@@ -36,33 +26,67 @@ impl<'src> Base<'src> {
     }
 }
 
-impl<'src> fmt::Debug for Base<'src> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_tuple("Base").field(&self.name()).finish()
+pub fn eq<'src>(x: &Value<'src>, y: &Value<'src>) -> LResult<'src> {
+    Ok(Value::Boolean(x == y))
+}
+
+pub fn add<'src>(x: &Value<'src>, y: &Value<'src>) -> LResult<'src> {
+    match (x, y) {
+        (Value::Number(x), Value::Number(y)) => Ok(Value::Number(x + y)),
+        _ => Err(LudusError {
+            msg: "add takes two numbers".to_string(),
+        }),
+    }
+}
+
+pub fn sub<'src>(x: &Value<'src>, y: &Value<'src>) -> LResult<'src> {
+    match (x, y) {
+        (Value::Number(x), Value::Number(y)) => Ok(Value::Number(x - y)),
+        _ => Err(LudusError {
+            msg: "sub takes two numbers".to_string(),
+        }),
+    }
+}
+
+pub fn unbox<'src>(x: &Value<'src>) -> LResult<'src> {
+    match x {
+        Value::Box(_, cell) => Ok(cell.borrow().clone()),
+        _ => Err(LudusError {
+            msg: "only boxes may be unboxed".to_string(),
+        }),
+    }
+}
+
+pub fn store<'src>(b: &Value<'src>, val: &Value<'src>) -> LResult<'src> {
+    if let Value::Box(_, cell) = b {
+        cell.replace(val.clone());
+        Ok(val.clone())
+    } else {
+        Err(LudusError {
+            msg: "only boxes may store values".to_string(),
+        })
     }
 }
 
 pub fn base<'src>() -> Vec<(&'src str, Value<'src>)> {
     let mut base = vec![];
 
-    let eq = Base::Binary("eq", Box::new(|x, y| Ok(Value::Boolean(x == y))));
-    base.push(("eq", Value::Base(&eq)));
+    let eq = Base::Binary("eq", eq);
+    base.push(("eq", Value::Base(eq)));
 
-    let add = Base::Binary(
-        "add",
-        Box::new(|x, y| match (x, y) {
-            (Value::Number(x), Value::Number(y)) => Ok(Value::Number(x + y)),
-            _ => Err(LudusError {
-                msg: "I can only add numbers".to_string(),
-            }),
-        }),
-    );
-    base.push(("add", Value::Base(&add)));
+    let add = Base::Binary("add", add);
+    base.push(("add", Value::Base(add)));
+
+    base.push(("sub", Value::Base(Base::Binary("sub", sub))));
+
+    base.push(("unbox", Value::Base(Base::Unary("unbox", unbox))));
+
+    base.push(("store", Value::Base(Base::Binary("store", store))));
 
     base
 }
 
-// add (x, y) -> number
+// DONE add (x, y) -> number
 // and (x, y) -> value
 // assoc (x, y) -> dict
 // atan_2 (x) -> number
@@ -78,6 +102,7 @@ pub fn base<'src>() -> Vec<(&'src str, Value<'src>)> {
 // div (x, y) -> number
 // doc (x) -> string
 // downcase (x) -> string
+// DONE eq (x, y) -> bool
 // first (x) -> value
 // floor (x) -> number
 // get (x, y) -> value
@@ -102,7 +127,7 @@ pub fn base<'src>() -> Vec<(&'src str, Value<'src>)> {
 // slice (x, y, z) -> list
 // split (x, y) -> list(string)
 // sqrt (x) -> number
-// store! (x, y) -> value
+// DONE store! (x, y) -> value
 // str_slice (x, y, z) -> string
 // stringify (x) -> string
 // sub (x, y) -> number
@@ -113,5 +138,5 @@ pub fn base<'src>() -> Vec<(&'src str, Value<'src>)> {
 // triml (x) -> string
 // trimr (x) -> string
 // type (x) -> keyword
-// unbox (x) -> value
+// DONE unbox (x) -> value
 // upcase (x) -> string

src/main.rs

@@ -26,7 +26,7 @@
 //     * [ ] splat patterns in tuples, lists, dicts
 //     * [ ] splats in list and dict literals
 //     * [ ] `loop` and `recur`
-// * [ ] write `base` in Rust
+// * [~] write `base` in Rust
 // * [ ] turn this into a library function
 // * [ ] compile this into WASM
 // * [ ] perf testing
@@ -53,7 +53,7 @@ use crate::base::*;
 
 pub fn main() {
     let src = "
-eq
+
     ";
     let (tokens, lex_errs) = lexer().parse(src).into_output_errors();
     if lex_errs.len() > 0 {

src/value.rs

@@ -28,7 +28,7 @@ pub enum Value<'src> {
     Dict(HashMap<&'src str, Self>),
     Box(&'src str, Rc<RefCell<Self>>),
     Fn(Rc<Fn<'src>>),
-    Base(&Base<'src>),
+    Base(Base<'src>),
     // Set(HashSet<Self>),
     // Sets are hard
     // Sets require Eq

src/vm.rs

@@ -174,6 +174,35 @@ pub fn apply<'src, 'a>(
         (_, Value::Args(_)) => Err(LudusError {
             msg: "you may only call a function".to_string(),
         }),
+        (Value::Base(f), Value::Tuple(args)) => match f {
+            Base::Unary(_name, f) => {
+                if args.len() != 1 {
+                    Err(LudusError {
+                        msg: "wrong arity: expected 1 argument".to_string(),
+                    })
+                } else {
+                    f(&args[0])
+                }
+            }
+            Base::Binary(_name, r#fn) => {
+                if args.len() != 2 {
+                    Err(LudusError {
+                        msg: "wrong arity: expected 2 arguments".to_string(),
+                    })
+                } else {
+                    r#fn(&args[0], &args[1])
+                }
+            }
+            Base::Ternary(_name, f) => {
+                if args.len() != 3 {
+                    Err(LudusError {
+                        msg: "wrong arity: expected 3 arguments".to_string(),
+                    })
+                } else {
+                    f(&args[0], &args[1], &args[2])
+                }
+            }
+        },
         _ => unreachable!(),
     }
 }