Fix aiken docs constant generation

Fixes #1048.

crates/aiken-lang/src/expr.rs

@@ -203,6 +203,22 @@ impl<T> From<Vec1Ref<T>> for Vec1<T> {
 }
 
 impl TypedExpr {
+    pub fn is_simple_expr_to_format(&self) -> bool {
+        match self {
+            Self::String { .. } | Self::UInt { .. } | Self::ByteArray { .. } | Self::Var { .. } => {
+                true
+            }
+            Self::Pair { fst, snd, .. } => {
+                fst.is_simple_expr_to_format() && snd.is_simple_expr_to_format()
+            }
+            Self::Tuple { elems, .. } => elems.iter().all(|e| e.is_simple_expr_to_format()),
+            Self::List { elements, .. } if elements.len() <= 3 => {
+                elements.iter().all(|e| e.is_simple_expr_to_format())
+            }
+            _ => false,
+        }
+    }
+
     pub fn and_then(self, next: Self) -> Self {
         if let TypedExpr::Trace {
             tipo,

crates/aiken-lang/src/format.rs

@@ -382,7 +382,18 @@ impl<'comments> Formatter<'comments> {
                     .append(wrap_args(elems.iter().map(|e| (self.const_expr(e), false))).group())
             }
             TypedExpr::List { elements, .. } => {
-                wrap_args(elements.iter().map(|e| (self.const_expr(e), false))).group()
+                let comma: fn() -> Document<'a> =
+                    if elements.iter().all(TypedExpr::is_simple_expr_to_format) {
+                        || flex_break(",", ", ")
+                    } else {
+                        || break_(",", ", ")
+                    };
+
+                list(
+                    join(elements.iter().map(|e| self.const_expr(e)), comma()),
+                    elements.len(),
+                    None,
+                )
             }
             TypedExpr::Var { name, .. } => name.to_doc(),
             _ => Document::Str(""),