From fe2a83174fa856752ac7b352ec4123a42e3337e0 Mon Sep 17 00:00:00 2001
From: Alek Ratzloff <alekratz@gmail.com>
Date: Wed, 16 Feb 2022 17:07:50 -0800
Subject: [PATCH] Add the start of array impl

* Array syntax
* Array compilation
* ArrayBegin and ArrayEnd inst
* mod obj::array

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>
---
 src/compile.rs      | 9 +++++++++
 src/obj/array.rs    | 0
 src/obj/mod.rs      | 2 ++
 src/syn/ast.rs      | 3 +++
 src/syn/parser.pest | 1 +
 src/syn/parser.rs   | 5 +++++
 src/vm/inst.rs      | 6 ++++++
 src/vm/machine.rs   | 6 ++++++
 8 files changed, 32 insertions(+)
 create mode 100644 src/obj/array.rs

diff --git a/src/compile.rs b/src/compile.rs
index a9bfab5..d736fab 100644
--- a/src/compile.rs
+++ b/src/compile.rs
@@ -70,6 +70,15 @@ impl<'s> Compile<'s> {
                 let inst = Inst::PushValue(QuoteObj::new(quote));
                 vec![SpInst::new(expr.span().clone(), inst)]
             }
+            Expr::Array(stmts) => {
+                self.scope_stack.push_scope();
+                let mut compiled = self.compile(stmts.clone());
+                let _locals = self.scope_stack.pop_scope().unwrap();
+                // Add prefix and suffix to the compiled items
+                compiled.insert(0, SpInst::new(expr.span().clone(), Inst::BeginArray));
+                compiled.push(SpInst::new(expr.span().clone(), Inst::EndArray));
+                compiled
+            }
         }
     }
 
diff --git a/src/obj/array.rs b/src/obj/array.rs
new file mode 100644
index 0000000..e69de29
diff --git a/src/obj/mod.rs b/src/obj/mod.rs
index eb70140..f56844e 100644
--- a/src/obj/mod.rs
+++ b/src/obj/mod.rs
@@ -1,5 +1,6 @@
 #[macro_use]
 mod macros;
+pub mod array;
 pub mod bool;
 pub mod builtin;
 pub mod float;
@@ -8,6 +9,7 @@ pub mod quote;
 pub mod str;
 
 pub mod prelude {
+    pub use crate::obj::array::*;
     pub use crate::obj::bool::*;
     pub use crate::obj::builtin::*;
     pub use crate::obj::float::*;
diff --git a/src/syn/ast.rs b/src/syn/ast.rs
index f3403a7..89c78ab 100644
--- a/src/syn/ast.rs
+++ b/src/syn/ast.rs
@@ -22,6 +22,9 @@ pub enum Expr {
 
     /// A quoted expression list.
     Quote(Vec<SpStmt>),
+
+    /// A list of statements that create the items of an array.
+    Array(Vec<SpStmt>),
 }
 
 /// A single, finite value.
diff --git a/src/syn/parser.pest b/src/syn/parser.pest
index 8427318..54ba63c 100644
--- a/src/syn/parser.pest
+++ b/src/syn/parser.pest
@@ -19,6 +19,7 @@ apply = @{ "!" }
 assign = { ":" ~ word }
 atom = { float | int | assign | word | str | apply }
 quote = { "[" ~ stmt* ~ "]" }
+array = { "{" ~ stmt* ~ "}" }
 expr = { atom | quote }
 include = { "%include" ~ str }
 stmt = { include | expr }
diff --git a/src/syn/parser.rs b/src/syn/parser.rs
index d936642..2dbfcaa 100644
--- a/src/syn/parser.rs
+++ b/src/syn/parser.rs
@@ -81,6 +81,11 @@ fn parse_expr(source: &Rc<String>, pair: Pair<Rule>) -> Result<SpExpr> {
                 .map(|pair| parse_stmt(source, pair.into_inner().next().unwrap()))
                 .collect::<Result<Vec<_>>>()?,
         ),
+        Rule::array => Expr::Array(
+            pair.into_inner()
+                .map(|pair| parse_stmt(source, pair.into_inner().next().unwrap()))
+                .collect::<Result<Vec<_>>>()?,
+        ),
         rule => unreachable!("{:?}", rule),
     };
     let span = Span {
diff --git a/src/vm/inst.rs b/src/vm/inst.rs
index 17d3188..c479259 100644
--- a/src/vm/inst.rs
+++ b/src/vm/inst.rs
@@ -17,6 +17,12 @@ pub enum Inst {
     //Dup,
     /// Applies the top stack value, which should be a macro.
     Call,
+
+    /// Begin creating a new array object.
+    BeginArray,
+
+    /// End creating a new array object.
+    EndArray,
 }
 
 pub type SpInst = Spanned<Inst>;
diff --git a/src/vm/machine.rs b/src/vm/machine.rs
index cd6f7fc..7bd1ccc 100644
--- a/src/vm/machine.rs
+++ b/src/vm/machine.rs
@@ -295,6 +295,12 @@ impl Machine {
                 let value = self.stack_pop()?;
                 value.call(Some(inst.span().clone()), self)?;
             }
+            Inst::BeginArray => {
+                todo!()
+            }
+            Inst::EndArray => {
+                todo!()
+            }
         };
 
         // Update this frame's PC