More Walk cleanup

- The `Node` type contained two enums by mistake. Those have been
   removed.

 - Export the `Visitor` and `Visitable` traits, as I start to migrate
   stuff to them.

 - Add a wrapper to pull the `digest` off the node without doing a
   `match` elsewhere.

src/wasm-lib/kcl/src/parsing/ast/digest.rs

@@ -4,7 +4,7 @@ use super::types::{DefaultParamVal, ItemVisibility, VariableKind};
 use crate::parsing::ast::types::{
     ArrayExpression, ArrayRangeExpression, BinaryExpression, BinaryPart, BodyItem, CallExpression, CallExpressionKw,
     CommentStyle, ElseIf, Expr, ExpressionStatement, FnArgType, FunctionExpression, Identifier, IfExpression,
-    ImportItem, ImportSelector, ImportStatement, Literal, LiteralIdentifier, MemberExpression, MemberObject,
+    ImportItem, ImportSelector, ImportStatement, KclNone, Literal, LiteralIdentifier, MemberExpression, MemberObject,
     NonCodeMeta, NonCodeNode, NonCodeValue, ObjectExpression, ObjectProperty, Parameter, PipeExpression,
     PipeSubstitution, Program, ReturnStatement, TagDeclarator, UnaryExpression, VariableDeclaration,
     VariableDeclarator,
@@ -202,6 +202,12 @@ impl Parameter {
     });
 }
 
+impl KclNone {
+    compute_digest!(|slf, hasher| {
+        hasher.update(b"KclNone");
+    });
+}
+
 impl FunctionExpression {
     compute_digest!(|slf, hasher| {
         hasher.update(slf.params.len().to_ne_bytes());

src/wasm-lib/kcl/src/parsing/ast/types/none.rs

@@ -3,7 +3,7 @@
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
-use super::Node;
+use super::{super::digest::Digest, Node};
 use crate::{execution::KclValue, parsing::ast::types::ConstraintLevel};
 
 const KCL_NONE_ID: &str = "KCL_NONE_ID";
@@ -19,11 +19,18 @@ pub struct KclNone {
     #[ts(skip)]
     #[schemars(skip)]
     __private: Private,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub digest: Option<Digest>,
 }
 
 impl KclNone {
     pub fn new() -> Self {
-        Self { __private: Private {} }
+        Self {
+            __private: Private {},
+            digest: None,
+        }
     }
 }
 

src/wasm-lib/kcl/src/walk/ast_node.rs

@@ -37,12 +37,45 @@ pub enum Node<'a> {
 
     ObjectProperty(NodeRef<'a, types::ObjectProperty>),
 
-    MemberObject(&'a types::MemberObject),
-    LiteralIdentifier(&'a types::LiteralIdentifier),
-
     KclNone(&'a types::KclNone),
 }
 
+impl<'tree> Node<'tree> {
+    /// Return the digest of the [Node], pulling the underlying Digest from
+    /// the AST types.
+    ///
+    /// The Digest type may change over time.
+    pub fn digest(&self) -> Option<[u8; 32]> {
+        match self {
+            Node::Program(n) => n.digest,
+            Node::ImportStatement(n) => n.digest,
+            Node::ExpressionStatement(n) => n.digest,
+            Node::VariableDeclaration(n) => n.digest,
+            Node::ReturnStatement(n) => n.digest,
+            Node::VariableDeclarator(n) => n.digest,
+            Node::Literal(n) => n.digest,
+            Node::TagDeclarator(n) => n.digest,
+            Node::Identifier(n) => n.digest,
+            Node::BinaryExpression(n) => n.digest,
+            Node::FunctionExpression(n) => n.digest,
+            Node::CallExpression(n) => n.digest,
+            Node::CallExpressionKw(n) => n.digest,
+            Node::PipeExpression(n) => n.digest,
+            Node::PipeSubstitution(n) => n.digest,
+            Node::ArrayExpression(n) => n.digest,
+            Node::ArrayRangeExpression(n) => n.digest,
+            Node::ObjectExpression(n) => n.digest,
+            Node::MemberExpression(n) => n.digest,
+            Node::UnaryExpression(n) => n.digest,
+            Node::Parameter(p) => p.digest,
+            Node::ObjectProperty(n) => n.digest,
+            Node::IfExpression(n) => n.digest,
+            Node::ElseIf(n) => n.digest,
+            Node::KclNone(n) => n.digest,
+        }
+    }
+}
+
 /// Returned during source_range conversion.
 #[derive(Debug)]
 pub enum AstNodeError {
@@ -77,9 +110,7 @@ impl TryFrom<&Node<'_>> for SourceRange {
             Node::UnaryExpression(n) => SourceRange::from(*n),
             Node::Parameter(p) => SourceRange::from(&p.identifier),
             Node::ObjectProperty(n) => SourceRange::from(*n),
-            Node::MemberObject(m) => SourceRange::new(m.start(), m.end(), m.module_id()),
             Node::IfExpression(n) => SourceRange::from(*n),
-            Node::LiteralIdentifier(l) => SourceRange::new(l.start(), l.end(), l.module_id()),
 
             // This is broken too
             Node::ElseIf(n) => SourceRange::new(n.cond.start(), n.cond.end(), n.cond.module_id()),
@@ -140,6 +171,24 @@ impl<'tree> From<&'tree types::BinaryPart> for Node<'tree> {
     }
 }
 
+impl<'tree> From<&'tree types::MemberObject> for Node<'tree> {
+    fn from(node: &'tree types::MemberObject) -> Self {
+        match node {
+            types::MemberObject::MemberExpression(me) => me.as_ref().into(),
+            types::MemberObject::Identifier(id) => id.as_ref().into(),
+        }
+    }
+}
+
+impl<'tree> From<&'tree types::LiteralIdentifier> for Node<'tree> {
+    fn from(node: &'tree types::LiteralIdentifier) -> Self {
+        match node {
+            types::LiteralIdentifier::Identifier(id) => id.as_ref().into(),
+            types::LiteralIdentifier::Literal(lit) => lit.as_ref().into(),
+        }
+    }
+}
+
 macro_rules! impl_from {
     ($node:ident, $t: ident) => {
         impl<'a> From<NodeRef<'a, types::$t>> for Node<'a> {
@@ -182,8 +231,6 @@ impl_from!(Node, MemberExpression);
 impl_from!(Node, UnaryExpression);
 impl_from!(Node, ObjectProperty);
 impl_from_ref!(Node, Parameter);
-impl_from_ref!(Node, MemberObject);
 impl_from!(Node, IfExpression);
 impl_from!(Node, ElseIf);
-impl_from_ref!(Node, LiteralIdentifier);
 impl_from!(Node, KclNone);

src/wasm-lib/kcl/src/walk/ast_visitor.rs

@@ -131,8 +131,6 @@ impl<'tree> Visitable<'tree> for Node<'tree> {
             | Node::TagDeclarator(_)
             | Node::Identifier(_)
             | Node::ImportStatement(_)
-            | Node::MemberObject(_)
-            | Node::LiteralIdentifier(_)
             | Node::KclNone(_)
             | Node::Literal(_) => vec![],
         }

src/wasm-lib/kcl/src/walk/mod.rs

@@ -3,4 +3,5 @@ mod ast_visitor;
 mod ast_walk;
 
 pub use ast_node::Node;
+pub use ast_visitor::{Visitable, Visitor};
 pub use ast_walk::walk;