array access via variables and len

src/interpret/interpret.rs

@@ -149,10 +149,20 @@ fn eval_expr(expr_env: &Env, state: &mut State, expr: &ast::Expr) -> Result<ast:
         }
         ast::Expr::Access { expr, field } => match eval_expr(expr_env, state, expr)? {
             ast::Value::Record(record) => Ok(state.variables.get(record.get(&field)?).clone()),
-            ast::Value::Vector(vec) if field.0.chars().all(char::is_numeric) => {
-                let index = field.0.parse::<usize>().unwrap();
-                Ok(state.variables.get(vec.get(index)?).clone())
-            }
+            ast::Value::Vector(vec) => match field {
+                _ if field.0.chars().all(char::is_numeric) => {
+                    let index = field.0.parse::<usize>().unwrap();
+                    Ok(state.variables.get(vec.get(index)?).clone())
+                }
+                _ if field.0 == "len" => Ok((vec.0.len() as i32).into()),
+                _ => match eval_expr(expr_env, state, &ast::Expr::Var(ast::Name(field.0.clone())))?
+                {
+                    ast::Value::Int(index) => {
+                        Ok(state.variables.get(vec.get(index as usize)?).clone())
+                    }
+                    v => Err(Error::NotAnInt(v, Backtrace::capture())),
+                },
+            },
             v => Err(Error::NotARecord(v, Backtrace::capture())),
         },
         ast::Expr::Var(var) => {
@@ -416,10 +426,18 @@ fn eval_expr_shallow(
         }
         ast::Expr::Access { expr, field } => match eval_expr(expr_env, state, expr)? {
             ast::Value::Record(record) => Ok(ast::Value::Ref(record.get(&field)?.clone())),
-            ast::Value::Vector(vec) if field.0.chars().all(char::is_numeric) => {
-                let index = field.0.parse::<usize>().unwrap();
-                Ok(ast::Value::Ref(vec.get(index)?.clone()))
-            }
+            ast::Value::Vector(vec) => match field {
+                _ if field.0.chars().all(char::is_numeric) => {
+                    let index = field.0.parse::<usize>().unwrap();
+                    Ok(ast::Value::Ref(vec.get(index)?.clone()))
+                }
+                _ => match eval_expr(expr_env, state, &ast::Expr::Var(ast::Name(field.0.clone())))?
+                {
+                    ast::Value::Int(index) => Ok(ast::Value::Ref(vec.get(index as usize)?.clone())),
+                    v => Err(Error::NotAnInt(v, Backtrace::capture())),
+                },
+            },
+
             v => Err(Error::NotARecord(v, Backtrace::capture())),
         },
         _ => eval_expr(expr_env, state, expr),

src/interpret/types.rs

@@ -18,6 +18,7 @@ pub enum Error {
     NotARecord(ast::Value, Backtrace),
     NotAReference(ast::Expr, ast::Value, Backtrace),
     NotABoolean(ast::Value, Backtrace),
+    NotAnInt(ast::Value, Backtrace),
     OpError(ast::Value, ast::Op, ast::Value, Backtrace),
     MigrationError(ast::Value, String, Backtrace),
     ArgumentsMismatch(Backtrace),
@@ -39,6 +40,7 @@ impl PartialEq for Error {
                 a1 == a2 && b1 == b2
             }
             (Error::NotABoolean(a1, _), Error::NotABoolean(a2, _)) => a1 == a2,
+            (Error::NotAnInt(a1, _), Error::NotAnInt(a2, _)) => a1 == a2,
             (Error::MigrationError(a1, b1, _), Error::MigrationError(a2, b2, _)) => {
                 a1 == a2 && b1 == b2
             }
@@ -76,6 +78,7 @@ impl std::fmt::Display for Error {
                 "Not a reference. Are you missing a `mut`? {a:?} {b:?}\n{c}"
             ),
             Error::NotABoolean(a, b) => write!(f, "Not a boolean {a:?}\n{b}"),
+            Error::NotAnInt(a, b) => write!(f, "Not an integer {a:?}\n{b}"),
             Error::ArgumentsMismatch(a) => write!(f, "Arguments mismatch\n{a}"),
             Error::OpError(a, b, c, d) => write!(f, "Op Error {a:?} {b:?} {c:?}\n{d}"),
             Error::MigrationError(a, b, c) => {

src/lib.rs

@@ -76,9 +76,9 @@ let counter = fn(a,b) {
   loop {
     if (a + count) >= b {
       break
-    };
+    }
     count = count + 1
-  };
+  }
   count
 }
 
@@ -90,6 +90,54 @@ let main = fn() {
         insta::assert_debug_snapshot!(result);
     }
 
+    #[test]
+    fn loop_sum_array() {
+        let program = "
+let summarize = fn(a,b) {
+  let array = [1,2,3,4,5,6,7,8,9]
+  let mut sum = 0
+  let mut index = 0
+  loop {
+    if index >= array.len {
+      break
+    }
+    sum = sum + array.index
+    index = index + 1
+  }
+  sum
+}
+
+let main = fn() {
+  summarize(1,10)
+}
+";
+        let result = run_main(program);
+        insta::assert_debug_snapshot!(result);
+    }
+
+    #[test]
+    fn map_array() {
+        let program = "
+let map = fn(f,array) {
+  let mut index = 0
+  loop {
+    if index >= array.len {
+      break
+    }
+    array.index = f(array.index)
+    index = index + 1
+  }
+  array
+}
+
+let main = fn() {
+  map(fn (x) { x + 1 }, [1,2,3])
+}
+";
+        let result = run_main(program);
+        insta::assert_debug_snapshot!(result);
+    }
+
     #[test]
     fn direction() {
         let program = "

src/snapshots/ayin__tests__loop_sum_array.snap

@@ -0,0 +1,11 @@
+---
+source: src/lib.rs
+expression: result
+---
+Ok(
+    Value(
+        Int(
+            45,
+        ),
+    ),
+)

src/snapshots/ayin__tests__map_array.snap

@@ -0,0 +1,25 @@
+---
+source: src/lib.rs
+expression: result
+---
+Ok(
+    Vector(
+        [
+            Value(
+                Int(
+                    2,
+                ),
+            ),
+            Value(
+                Int(
+                    3,
+                ),
+            ),
+            Value(
+                Int(
+                    4,
+                ),
+            ),
+        ],
+    ),
+)