From a13ad0edaa0cb5259a727e81ea4eac1591bb009e Mon Sep 17 00:00:00 2001
From: Greg Shuflin <greg.shuflin@protonmail.com>
Date: Tue, 2 Nov 2021 21:19:29 -0700
Subject: [PATCH] Implement list literals

---
 schala-lang/language/src/reduced_ir/mod.rs           |  2 +-
 schala-lang/language/src/reduced_ir/types.rs         |  1 +
 schala-lang/language/src/tree_walk_eval/evaluator.rs |  6 ++++++
 schala-lang/language/src/tree_walk_eval/mod.rs       | 12 +++++++-----
 schala-lang/language/src/tree_walk_eval/test.rs      | 11 +++++++++++
 5 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/schala-lang/language/src/reduced_ir/mod.rs b/schala-lang/language/src/reduced_ir/mod.rs
index b95a7c6..e4eb3f5 100644
--- a/schala-lang/language/src/reduced_ir/mod.rs
+++ b/schala-lang/language/src/reduced_ir/mod.rs
@@ -187,7 +187,7 @@ impl<'a, 'b> Reducer<'a, 'b> {
                 Expression::Loop { cond, statements }
             }
             ForExpression { .. } => Expression::ReductionError("For expr not implemented".to_string()),
-            ListLiteral { .. } => Expression::ReductionError("ListLiteral expr not implemented".to_string()),
+            ListLiteral(items) => Expression::List(items.iter().map(|item| self.expression(item)).collect()),
             Access { name, expr } =>
                 Expression::Access { name: name.as_ref().to_string(), expr: Box::new(self.expression(expr)) },
         }
diff --git a/schala-lang/language/src/reduced_ir/types.rs b/schala-lang/language/src/reduced_ir/types.rs
index 5927c88..21340bf 100644
--- a/schala-lang/language/src/reduced_ir/types.rs
+++ b/schala-lang/language/src/reduced_ir/types.rs
@@ -51,6 +51,7 @@ pub enum Statement {
 pub enum Expression {
     Literal(Literal),
     Tuple(Vec<Expression>),
+    List(Vec<Expression>),
     Lookup(Lookup),
     Assign { lval: DefId, rval: Box<Expression> },
     Access { name: String, expr: Box<Expression> },
diff --git a/schala-lang/language/src/tree_walk_eval/evaluator.rs b/schala-lang/language/src/tree_walk_eval/evaluator.rs
index 1f4bbc0..a242fab 100644
--- a/schala-lang/language/src/tree_walk_eval/evaluator.rs
+++ b/schala-lang/language/src/tree_walk_eval/evaluator.rs
@@ -111,6 +111,12 @@ impl<'a, 'b> Evaluator<'a, 'b> {
                     .map(|expr| self.expression(expr))
                     .collect::<EvalResult<Vec<Primitive>>>()?,
             ),
+            Expression::List(items) => Primitive::List(
+                items
+                    .into_iter()
+                    .map(|expr| self.expression(expr))
+                    .collect::<EvalResult<Vec<Primitive>>>()?,
+            ),
             Expression::Lookup(kind) => match kind {
                 Lookup::Function(ref id) => {
                     let mem = id.into();
diff --git a/schala-lang/language/src/tree_walk_eval/mod.rs b/schala-lang/language/src/tree_walk_eval/mod.rs
index 6468d95..5d22a1e 100644
--- a/schala-lang/language/src/tree_walk_eval/mod.rs
+++ b/schala-lang/language/src/tree_walk_eval/mod.rs
@@ -61,16 +61,16 @@ impl RuntimeError {
     }
 }
 
-fn paren_wrapped(terms: impl Iterator<Item = String>) -> String {
+fn delim_wrapped(lhs: char, rhs: char, terms: impl Iterator<Item = String>) -> String {
     let mut buf = String::new();
-    write!(buf, "(").unwrap();
+    write!(buf, "{}", lhs).unwrap();
     for term in terms.map(Some).intersperse(None) {
         match term {
             Some(e) => write!(buf, "{}", e).unwrap(),
             None => write!(buf, ", ").unwrap(),
         };
     }
-    write!(buf, ")").unwrap();
+    write!(buf, "{}", rhs).unwrap();
     buf
 }
 
@@ -110,6 +110,7 @@ impl From<Primitive> for RuntimeValue {
 #[derive(Debug, Clone)]
 enum Primitive {
     Tuple(Vec<Primitive>),
+    List(Vec<Primitive>),
     Literal(Literal),
     Callable(Callable),
     Object { type_id: TypeId, tag: u32, ordered_fields: Option<Vec<String>>, items: Vec<Primitive> },
@@ -124,7 +125,7 @@ impl Primitive {
                 format!(
                     "{}{}",
                     type_context.variant_local_name(type_id, *tag).unwrap(),
-                    paren_wrapped(items.iter().map(|item| item.to_repl(type_context)))
+                    delim_wrapped('(', ')', items.iter().map(|item| item.to_repl(type_context)))
                 )
             }
             Primitive::Object { type_id, items, tag, ordered_fields: Some(fields) } => {
@@ -145,7 +146,8 @@ impl Primitive {
                 Literal::Bool(b) => format!("{}", b),
                 Literal::StringLit(s) => format!("\"{}\"", s),
             },
-            Primitive::Tuple(terms) => paren_wrapped(terms.iter().map(|x| x.to_repl(type_context))),
+            Primitive::Tuple(terms) => delim_wrapped('(', ')', terms.iter().map(|x| x.to_repl(type_context))),
+            Primitive::List(terms) => delim_wrapped('[', ']', terms.iter().map(|x| x.to_repl(type_context))),
             Primitive::Callable(..) => "<some-callable>".to_string(),
         }
     }
diff --git a/schala-lang/language/src/tree_walk_eval/test.rs b/schala-lang/language/src/tree_walk_eval/test.rs
index 2184776..88dfcdb 100644
--- a/schala-lang/language/src/tree_walk_eval/test.rs
+++ b/schala-lang/language/src/tree_walk_eval/test.rs
@@ -526,3 +526,14 @@ while a < 10 {
 acc"#;
     eval_assert(source, "19");
 }
+
+#[test]
+fn list_literals() {
+    eval_assert(
+        r#"
+let a = [7, 8, 9]
+a
+"#,
+        "[7, 8, 9]",
+    );
+}