From b4094bf57008200ec9f47c14f18a64310baf0162 Mon Sep 17 00:00:00 2001
From: Jesse Brault <jbrault@mac.com>
Date: Sun, 15 Mar 2026 19:18:27 -0500
Subject: [PATCH] Sketching array-related things.

---
 dmc-lib/src/lexer.rs          |  4 ++++
 dmc-lib/src/parser.rs         | 36 ++++++++++++++++++++++++----
 dmc-lib/src/token.rs          |  2 ++
 dvm-lib/src/vm/array.rs       | 44 +++++++++++++++++++++++++++++++++++
 dvm-lib/src/vm/mod.rs         |  1 +
 sketching/march_2026/array.dm | 40 +++++++++++++++++++++++++++++++
 6 files changed, 122 insertions(+), 5 deletions(-)
 create mode 100644 dvm-lib/src/vm/array.rs
 create mode 100644 sketching/march_2026/array.dm

diff --git a/dmc-lib/src/lexer.rs b/dmc-lib/src/lexer.rs
index 0433c3e..423c148 100644
--- a/dmc-lib/src/lexer.rs
+++ b/dmc-lib/src/lexer.rs
@@ -72,6 +72,10 @@ impl<'a> Lexer<'a> {
             Token::new(self.position, self.position + 1, TokenKind::Colon)
         } else if chunk.starts_with(".") {
             Token::new(self.position, self.position + 1, TokenKind::Dot)
+        } else if chunk.starts_with("[") {
+            Token::new(self.position, self.position + 1, TokenKind::LeftSquare)
+        } else if chunk.starts_with("]") {
+            Token::new(self.position, self.position + 1, TokenKind::RightSquare)
         } else {
             // more than one char token
             if chunk.starts_with(|c: char| c.is_ascii_digit()) {
diff --git a/dmc-lib/src/parser.rs b/dmc-lib/src/parser.rs
index 259135a..4b81164 100644
--- a/dmc-lib/src/parser.rs
+++ b/dmc-lib/src/parser.rs
@@ -477,11 +477,37 @@ impl<'a> Parser<'a> {
     }
 
     fn type_use(&mut self) -> Result<TypeUse, Vec<Diagnostic>> {
-        let identifier_token = self.expect_advance(TokenKind::Identifier)?;
-        Ok(TypeUse::new(
-            self.token_text(&identifier_token),
-            SourceRange::new(identifier_token.start(), identifier_token.end()),
-        ))
+        if self.current.is_some() {
+            let current = self.get_current();
+            return match current.kind() {
+                TokenKind::LeftSquare => {
+                    self.advance(); // [
+                    let inner_type_use = self.type_use()?;
+                    self.expect_advance(TokenKind::RightSquare)?;
+                    todo!()
+                }
+                TokenKind::Identifier => {
+                    let identifier_token = self.expect_advance(TokenKind::Identifier)?;
+                    Ok(TypeUse::new(
+                        self.token_text(&identifier_token),
+                        SourceRange::new(identifier_token.start(), identifier_token.end()),
+                    ))
+                }
+                _ => Err(vec![Diagnostic::new(
+                    &format!(
+                        "Expected LeftSquare or Identifier; found: {:?}",
+                        current.kind()
+                    ),
+                    current.start(),
+                    current.end(),
+                )]),
+            };
+        }
+        Err(vec![Diagnostic::new(
+            "Expected LeftSquare or Identifier; found end of input.",
+            self.input.len(),
+            self.input.len(),
+        )])
     }
 
     fn public_class_member(
diff --git a/dmc-lib/src/token.rs b/dmc-lib/src/token.rs
index 5e0084a..be7bef6 100644
--- a/dmc-lib/src/token.rs
+++ b/dmc-lib/src/token.rs
@@ -56,4 +56,6 @@ pub enum TokenKind {
     Public,
     Mut,
     Ctor,
+    LeftSquare,
+    RightSquare,
 }
diff --git a/dvm-lib/src/vm/array.rs b/dvm-lib/src/vm/array.rs
new file mode 100644
index 0000000..3714e8c
--- /dev/null
+++ b/dvm-lib/src/vm/array.rs
@@ -0,0 +1,44 @@
+use std::alloc::{Layout, alloc};
+
+#[derive(Debug)]
+#[repr(C)]
+pub struct Array<T> {
+    header: ArrayHeader,
+    data: [T],
+}
+
+#[derive(Debug)]
+pub struct ArrayHeader {
+    length: usize,
+}
+
+pub fn get_array<T: Clone>(length: usize, init: T) -> Box<Array<T>> {
+    let (layout, data_base) = Layout::array::<T>(length)
+        .and_then(|data_layout| Layout::new::<ArrayHeader>().extend(data_layout))
+        .unwrap();
+    let ptr = unsafe { alloc(layout) };
+    if ptr.is_null() {
+        panic!("failed to allocate memory");
+    }
+    unsafe {
+        ptr.cast::<ArrayHeader>().write(ArrayHeader { length });
+        let data_ptr = ptr.add(data_base).cast::<T>();
+        for i in 0..length {
+            data_ptr.add(i).write(init.clone());
+        }
+
+        Box::from_raw(std::ptr::slice_from_raw_parts(ptr as *mut T, length) as *mut Array<T>)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::vm::array::get_array;
+
+    #[test]
+    fn int_array() {
+        let int_array = get_array::<i32>(5, 0);
+        assert_eq!(int_array.data.len(), 5);
+        assert_eq!(int_array.header.length, 5);
+    }
+}
diff --git a/dvm-lib/src/vm/mod.rs b/dvm-lib/src/vm/mod.rs
index abc36ff..7350159 100644
--- a/dvm-lib/src/vm/mod.rs
+++ b/dvm-lib/src/vm/mod.rs
@@ -17,6 +17,7 @@ use std::collections::HashMap;
 use std::ptr;
 use std::rc::Rc;
 
+pub mod array;
 pub mod class;
 pub mod constant;
 pub mod function;
diff --git a/sketching/march_2026/array.dm b/sketching/march_2026/array.dm
new file mode 100644
index 0000000..179232b
--- /dev/null
+++ b/sketching/march_2026/array.dm
@@ -0,0 +1,40 @@
+fn main(args: [String])
+    println(args[0])
+end
+
+int Index<T, I>
+    op [](i: I) -> T
+end
+
+int Slice<T> : Index<T, ISize>, Iterable<T>
+    length: ISize
+
+    def fn iter() -> Iterator<T>
+        let mut i = 0
+        {
+            if i < length then
+                i++
+                Some(self[i - 1])
+            else
+                None
+            end
+        }
+    end
+end
+
+int Iterator<T>
+    fn next() -> Option<T>
+end
+
+int Iterable<T>
+    fn iter() -> Iterator<T>
+end
+
+extern class Array<T> : Index<T, ISize>, Slice<T>
+    extern length: ISize
+    extern op [](i: ISize) -> T
+end
+
+int List<T> : Index<T, ISize>, Slice<T>
+
+end
\ No newline at end of file