diff --git a/ast-generator/src/build_fn/struct_build_fn.rs b/ast-generator/src/build_fn/struct_build_fn.rs
index 5c0b3f6..962a8db 100644
--- a/ast-generator/src/build_fn/struct_build_fn.rs
+++ b/ast-generator/src/build_fn/struct_build_fn.rs
@@ -1,5 +1,8 @@
 use crate::deserialize::util::{make_build_fn_name, make_build_pair};
-use crate::spec::struct_spec::{MemberChildBuild, NodeMemberBuild, SpecialChild, SpecialChildKind, StructChild, StructSpec, VecChild, VecChildBuild};
+use crate::spec::struct_spec::{
+    MemberChildBuild, NodeMemberBuild, SpecialChild, SpecialChildKind, StructChild, StructSpec,
+    VecChild, VecChildBuild,
+};
 use proc_macro2::{Ident, TokenStream};
 use quote::{format_ident, quote};
 
@@ -118,14 +121,14 @@ fn make_boolean_member_child_match_action(name: &str) -> TokenStream {
     }
 }
 
-fn make_rule_matcher(child_spec: &StructChild) -> Option<TokenStream> {    
+fn make_rule_matcher(child_spec: &StructChild) -> Option<TokenStream> {
     match child_spec {
         StructChild::SkipChild(skip_child) => {
             let rule_ident = format_ident!("{}", skip_child.rule());
             Some(quote! {
                 Rule::#rule_ident => {}
             })
-        },
+        }
         StructChild::VecChild(vec_child) => {
             let rule_ident = format_ident!("{}", vec_child.rule());
             let action = make_vec_child_match_action(vec_child);
@@ -133,28 +136,24 @@ fn make_rule_matcher(child_spec: &StructChild) -> Option<TokenStream> {
                 Rule::#rule_ident => { #action }
             })
         }
-        StructChild::MemberChild(member_child) => {
-            match member_child.build() {
-                MemberChildBuild::Node(node_member_build) => {
-                    let rule_ident = format_ident!("{}", member_child.rule());
-                    let action = make_node_member_child_match_action(
-                        member_child.name(),
-                        node_member_build
-                    );
-                    Some(quote! {
-                        Rule::#rule_ident => { #action }
-                    })
-                }
-                MemberChildBuild::Boolean(_) => {
-                    let rule_ident = format_ident!("{}", member_child.rule());
-                    let action = make_boolean_member_child_match_action(member_child.name());
-                    Some(quote! {
-                        Rule::#rule_ident => { #action }
-                    })
-                }
+        StructChild::MemberChild(member_child) => match member_child.build() {
+            MemberChildBuild::Node(node_member_build) => {
+                let rule_ident = format_ident!("{}", member_child.rule());
+                let action =
+                    make_node_member_child_match_action(member_child.name(), node_member_build);
+                Some(quote! {
+                    Rule::#rule_ident => { #action }
+                })
+            }
+            MemberChildBuild::Boolean(_) => {
+                let rule_ident = format_ident!("{}", member_child.rule());
+                let action = make_boolean_member_child_match_action(member_child.name());
+                Some(quote! {
+                    Rule::#rule_ident => { #action }
+                })
             }
         },
-        StructChild::Special(_) => None
+        StructChild::Special(_) => None,
     }
 }
 
@@ -192,7 +191,7 @@ fn make_special_child_arg(special_child: &SpecialChild) -> TokenStream {
     quote! { #child_ident }
 }
 
-fn make_child_arg(child_spec: &StructChild, pair_ident: &Ident) -> Option<TokenStream> {
+fn make_child_arg(child_spec: &StructChild) -> Option<TokenStream> {
     match child_spec {
         StructChild::SkipChild(_) => None,
         StructChild::VecChild(vec_child) => Some(make_vec_child_arg(vec_child)),
@@ -204,7 +203,7 @@ fn make_child_arg(child_spec: &StructChild, pair_ident: &Ident) -> Option<TokenS
             )),
             MemberChildBuild::Boolean(_) => {
                 Some(make_boolean_member_child_arg(member_child.name()))
-            },
+            }
         },
         StructChild::Special(special_child) => Some(make_special_child_arg(special_child)),
     }
@@ -214,7 +213,7 @@ fn make_return_value_stream(build_spec: &StructSpec, pair_ident: &Ident) -> Toke
     let type_ident = format_ident!("{}", build_spec.build());
     let child_args = build_spec
         .children()
-        .map(|child| make_child_arg(child, pair_ident))
+        .map(|child| make_child_arg(child))
         .filter(|child_arg| child_arg.is_some())
         .map(|child_arg| child_arg.unwrap())
         .collect::<Vec<_>>();
@@ -230,9 +229,9 @@ pub fn make_struct_build_fn(build_spec: &StructSpec) -> TokenStream {
     let build_fn_ident = format_ident!("{}", make_build_fn_name(build_spec.build()));
     let pair_ident = format_ident!("{}", make_build_pair(build_spec.build()));
     let return_type_ident = format_ident!("{}", build_spec.build());
-    
+
     let preamble = make_preamble(build_spec, &pair_ident);
-    
+
     let special_children = make_special_children(build_spec);
 
     let child_holders = build_spec
@@ -261,9 +260,9 @@ pub fn make_struct_build_fn(build_spec: &StructSpec) -> TokenStream {
     quote! {
         fn #build_fn_ident(file_id: usize, #pair_ident: Pair<Rule>) -> #return_type_ident {
             #preamble
-            
+
             #(#special_children;)*
-            
+
             #(#child_holders;)*
 
             #iter_stream
diff --git a/ast-generator/src/deserialize/struct_spec.rs b/ast-generator/src/deserialize/struct_spec.rs
index bae37c8..720b824 100644
--- a/ast-generator/src/deserialize/struct_spec.rs
+++ b/ast-generator/src/deserialize/struct_spec.rs
@@ -5,6 +5,23 @@ use crate::deserialize::util::{get_as_bool, make_build_fn_name, unwrap_single_me
 use crate::spec::struct_spec::*;
 use yaml_rust2::Yaml;
 
+fn deserialize_fields(fields: &Yaml) -> Vec<Box<StructField>> {
+    fields
+        .as_vec()
+        .unwrap()
+        .iter()
+        .map(|field| unwrap_single_member_hash(field))
+        .map(|(name, props)| {
+            let kind = match props["kind"].as_str().unwrap() {
+                "usize" => StructFieldKind::USize,
+                _ => panic!()
+            };
+            StructField::new(&name, kind, get_as_bool(&props["optional"]))
+        })
+        .map(Box::new)
+        .collect()
+}
+
 fn deserialize_skip_child(props: &Yaml) -> StructChild {
     let rule = props["rule"].as_str().unwrap();
     StructChild::SkipChild(SkipChild::new(rule))
@@ -96,8 +113,12 @@ fn deserialize_special_child(name: &str, props: &Yaml) -> StructChild {
     match props["kind"].as_str().unwrap() {
         "file_id" => StructChild::Special(SpecialChild::new(name, SpecialChildKind::FileId)),
         "range" => StructChild::Special(SpecialChild::new(name, SpecialChildKind::Range)),
-        _ => panic!("Invalid special child kind {} in {}", props["kind"].as_str().unwrap(), name),
-    }    
+        _ => panic!(
+            "Invalid special child kind {} in {}",
+            props["kind"].as_str().unwrap(),
+            name
+        ),
+    }
 }
 
 fn deserialize_hash_child(name: &str, props: &Yaml) -> StructChild {
@@ -108,7 +129,7 @@ fn deserialize_hash_child(name: &str, props: &Yaml) -> StructChild {
     } else if props["member"].is_hash() {
         deserialize_member_child(name, &props["member"])
     } else if props["special"].is_hash() {
-        deserialize_special_child(name, &props["special"])    
+        deserialize_special_child(name, &props["special"])
     } else {
         panic!("Expected 'skip' or 'vec' in 'member' in {}", name);
     }
@@ -151,5 +172,11 @@ pub fn deserialize_struct_spec(name: &str, struct_yaml: &Yaml) -> StructSpec {
     } else {
         deserialize_error!("array", "children", name);
     };
-    StructSpec::new(name, children)
+    let fields = if struct_yaml["fields"].is_array() {
+        deserialize_fields(&struct_yaml["fields"])
+    } else {
+        vec![]
+    };
+
+    StructSpec::new(name, children, fields)
 }
diff --git a/ast-generator/src/spec/struct_spec.rs b/ast-generator/src/spec/struct_spec.rs
index e8a593e..27cb7a1 100644
--- a/ast-generator/src/spec/struct_spec.rs
+++ b/ast-generator/src/spec/struct_spec.rs
@@ -1,13 +1,19 @@
 pub struct StructSpec {
     build: String,
     children: Vec<Box<StructChild>>,
+    fields: Vec<Box<StructField>>,
 }
 
 impl StructSpec {
-    pub fn new(build: &str, children: Vec<Box<StructChild>>) -> Self {
+    pub fn new(
+        build: &str,
+        children: Vec<Box<StructChild>>,
+        fields: Vec<Box<StructField>>,
+    ) -> Self {
         Self {
             build: build.to_string(),
             children,
+            fields,
         }
     }
 
@@ -20,6 +26,10 @@ impl StructSpec {
     pub fn children(&self) -> impl Iterator<Item = &StructChild> {
         self.children.iter().map(Box::as_ref)
     }
+
+    pub fn fields(&self) -> impl Iterator<Item = &StructField> {
+        self.fields.iter().map(Box::as_ref)
+    }
 }
 
 pub enum StructChild {
@@ -36,13 +46,11 @@ impl StructChild {
             _ => false,
         }
     }
-    
+
     pub fn unwrap_special(&self) -> Option<&SpecialChild> {
         match self {
-            StructChild::Special(special_child) => {
-                Some(special_child)
-            },
-            _ => None
+            StructChild::Special(special_child) => Some(special_child),
+            _ => None,
         }
     }
 }
@@ -242,14 +250,14 @@ impl SpecialChild {
     pub fn new(name: &str, kind: SpecialChildKind) -> Self {
         Self {
             name: name.to_string(),
-            kind
+            kind,
         }
     }
-    
+
     pub fn name(&self) -> &str {
         &self.name
     }
-    
+
     pub fn kind(&self) -> &SpecialChildKind {
         &self.kind
     }
@@ -260,3 +268,35 @@ pub enum SpecialChildKind {
     FileId,
     Range,
 }
+
+pub struct StructField {
+    name: String,
+    kind: StructFieldKind,
+    optional: bool,
+}
+
+impl StructField {
+    pub fn new(name: &str, kind: StructFieldKind, optional: bool) -> Self {
+        Self {
+            name: name.to_string(),
+            kind,
+            optional,
+        }
+    }
+    
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+    
+    pub fn kind(&self) -> &StructFieldKind {
+        &self.kind
+    }
+    
+    pub fn optional(&self) -> bool {
+        self.optional
+    }
+}
+
+pub enum StructFieldKind {
+    USize,
+}
diff --git a/ast-generator/src/type_gen/struct_type.rs b/ast-generator/src/type_gen/struct_type.rs
index 72d3f1f..2ca4ee1 100644
--- a/ast-generator/src/type_gen/struct_type.rs
+++ b/ast-generator/src/type_gen/struct_type.rs
@@ -1,6 +1,6 @@
 use crate::spec::struct_spec::{
-    MemberChild, MemberChildBuild, SpecialChild, SpecialChildKind, StructChild, StructSpec,
-    VecChild, VecChildBuild,
+    MemberChild, MemberChildBuild, SpecialChild, SpecialChildKind, StructChild, StructField,
+    StructFieldKind, StructSpec, VecChild, VecChildBuild,
 };
 use proc_macro2::{Ident, TokenStream};
 use quote::{format_ident, quote};
@@ -99,7 +99,7 @@ fn make_special_child_accessors(special_child: &SpecialChild) -> TokenStream {
     }
 }
 
-fn make_accessors(child: &StructChild) -> Option<TokenStream> {
+fn make_child_accessors(child: &StructChild) -> Option<TokenStream> {
     match child {
         StructChild::SkipChild(_) => None,
         StructChild::VecChild(vec_child) => Some(make_vec_child_accessors(vec_child)),
@@ -182,15 +182,68 @@ fn make_annotated_member(child: &StructChild) -> Option<TokenStream> {
     }
 }
 
+fn make_annotated_field(field: &StructField) -> TokenStream {
+    let field_ident = format_ident!("{}", field.name());
+    let field_type_ident = match field.kind() {
+        StructFieldKind::USize => quote! { usize },
+    };
+    if field.optional() {
+        quote! {
+            #field_ident: Option<#field_type_ident>
+        }
+    } else {
+        quote! {
+            #field_ident: #field_type_ident
+        }
+    }
+}
+
+fn make_field_init(field: &StructField) -> TokenStream {
+    let field_ident = format_ident!("{}", field.name());
+    if field.optional() {
+        quote! {
+            #field_ident: None
+        }
+    } else {
+        todo!()
+    }
+}
+
+fn make_field_accessors(field: &StructField) -> TokenStream {
+    let field_ident = format_ident!("{}", field.name());
+    let field_type_ident = match field.kind() {
+        StructFieldKind::USize => quote! { usize },
+    };
+    if field.optional() {
+        let setter_ident = format_ident!("set_{}", field.name());
+        quote! {
+            pub fn #field_ident(&self) -> Option<#field_type_ident> {
+                self.#field_ident
+            }
+
+            pub fn #setter_ident(&mut self, #field_ident: #field_type_ident) {
+                self.#field_ident = Some(#field_ident);
+            }
+        }
+    } else {
+        todo!()
+    }
+}
+
 pub fn make_struct_type(build_spec: &StructSpec) -> TokenStream {
     let type_ident = format_ident!("{}", build_spec.build());
-    let annotated_members = build_spec
+    let annotated_children = build_spec
         .children()
         .map(|child| make_annotated_member(child))
         .filter(Option::is_some)
         .map(Option::unwrap)
         .collect::<Vec<_>>();
 
+    let annotated_fields = build_spec
+        .fields()
+        .map(|field| make_annotated_field(field))
+        .collect::<Vec<_>>();
+
     let member_names = build_spec
         .children()
         .map(|child| make_member_ident(child))
@@ -198,26 +251,39 @@ pub fn make_struct_type(build_spec: &StructSpec) -> TokenStream {
         .map(Option::unwrap)
         .collect::<Vec<_>>();
 
-    let accessors = build_spec
+    let field_inits = build_spec
+        .fields()
+        .map(|field| make_field_init(field))
+        .collect::<Vec<_>>();
+
+    let child_accessors = build_spec
         .children()
-        .map(|child| make_accessors(child))
+        .map(|child| make_child_accessors(child))
         .filter(Option::is_some)
         .map(Option::unwrap)
         .collect::<Vec<_>>();
 
+    let field_accessors = build_spec
+        .fields()
+        .map(|field| make_field_accessors(field))
+        .collect::<Vec<_>>();
+
     quote! {
         pub struct #type_ident {
-            #(#annotated_members),*
+            #(#annotated_children,)*
+            #(#annotated_fields,)*
         }
 
         impl #type_ident {
-            pub fn new(#(#annotated_members),*) -> Self {
+            pub fn new(#(#annotated_children),*) -> Self {
                 Self {
-                    #(#member_names),*
+                    #(#member_names,)*
+                    #(#field_inits,)*
                 }
             }
 
-            #(#accessors)*
+            #(#child_accessors)*
+            #(#field_accessors)*
         }
     }
 }
diff --git a/src/name_analysis/gather.rs b/src/name_analysis/gather.rs
index 14577bf..8b90cc9 100644
--- a/src/name_analysis/gather.rs
+++ b/src/name_analysis/gather.rs
@@ -209,59 +209,8 @@ fn gather_node(
         AstNodeRef::Member(member) => {
             gather_member(member, symbol_table, fqn_context, diagnostics);
         }
-        AstNodeRef::Statement(statement) => match statement {
-            Statement::VariableDeclaration(variable_declaration) => {
-                gather_node(
-                    variable_declaration.as_node_ref(),
-                    symbol_table,
-                    fqn_context,
-                    diagnostics,
-                );
-            }
-            Statement::AssignmentStatement(assignment_statement) => {
-                gather_node(
-                    assignment_statement.as_node_ref(),
-                    symbol_table,
-                    fqn_context,
-                    diagnostics,
-                );
-            }
-            Statement::ExpressionStatement(expression_statement) => {
-                gather_node(
-                    expression_statement.as_node_ref(),
-                    symbol_table,
-                    fqn_context,
-                    diagnostics,
-                );
-            }
-            Statement::UseStatement(use_statement) => {
-                gather_node(
-                    use_statement.as_node_ref(),
-                    symbol_table,
-                    fqn_context,
-                    diagnostics,
-                );
-            }
-            Statement::IfStatement(if_statement) => gather_node(
-                if_statement.as_node_ref(),
-                symbol_table,
-                fqn_context,
-                diagnostics,
-            ),
-            Statement::WhileStatement(while_statement) => gather_node(
-                while_statement.as_node_ref(),
-                symbol_table,
-                fqn_context,
-                diagnostics,
-            ),
-            Statement::ForStatement(for_statement) => {
-                gather_node(
-                    for_statement.as_node_ref(),
-                    symbol_table,
-                    fqn_context,
-                    diagnostics,
-                );
-            }
+        AstNodeRef::Statement(statement) => {
+            gather_node_children(statement, symbol_table, fqn_context, diagnostics);
         },
         AstNodeRef::VariableDeclaration(variable_declaration) => {
             gather_variable_declaration(
@@ -279,6 +228,9 @@ fn gather_node(
         AstNodeRef::IfElse(_) => {}
         AstNodeRef::WhileStatement(_) => {}
         AstNodeRef::ForStatement(_) => {}
+        AstNodeRef::LValue(_) => {},
+        AstNodeRef::LValueSuffix(_) => {},
+        AstNodeRef::VariableUse(_) => {},
         AstNodeRef::Expression(_) => {}
         AstNodeRef::TernaryExpression(_) => {}
         AstNodeRef::TernaryRhs(_) => {}
diff --git a/src/parser/ast.yaml b/src/parser/ast.yaml
index df559fb..421916d 100644
--- a/src/parser/ast.yaml
+++ b/src/parser/ast.yaml
@@ -1,16 +1,16 @@
 # $schema: ./ast.schema.yaml
 # Operators
 Operator:
-  struct: 
+  struct:
     children:
       - inner:
-          member: 
+          member:
             rule: OperatorInner
       - file_id:
-          special: 
+          special:
             kind: file_id
       - range:
-          special: 
+          special:
             kind: range
 OperatorInner:
   leaf_enum:
@@ -442,24 +442,24 @@ PlatformFunction:
       - parameters
       - return_type
 PlatformOperatorFunction:
-  struct: 
+  struct:
     children:
       - is_public:
-          member: 
+          member:
             rule: Pub
-            build: 
-              boolean: 
+            build:
+              boolean:
                 on: rule_present
       - platform_kw:
-          skip: 
+          skip:
             rule: Platform
       - op_kw:
           skip:
             rule: Op
       - generics:
-          member: 
+          member:
             rule: GenericParameters
-            build: 
+            build:
               node:
                 or_else_default: true
       - operator
@@ -628,12 +628,8 @@ VariableDeclaration:
 AssignmentStatement:
   struct:
     children:
-      - left:
-          member:
-            rule: Expression
-      - right:
-          member:
-            rule: Expression
+      - l_value
+      - expression
 ExpressionStatement:
   struct:
     children:
@@ -715,6 +711,30 @@ ForStatement:
           skip:
             rule: End
 
+# LValue
+LValue:
+  struct:
+    children:
+      - variable_use
+      - suffixes:
+          vec:
+            rule: LValueSuffix
+LValueSuffix:
+  tree_enum:
+    rules:
+      - ObjectProperty
+      - ObjectIndex
+
+# VariableUse
+VariableUse:
+  struct:
+    children:
+      - identifier
+    fields:
+      - scope_id:
+          kind: usize
+          optional: true
+
 # Expressions
 Expression:
   polymorphic_type:
@@ -749,6 +769,9 @@ Expression:
       - Literal:
           inner:
             kind: Literal
+      - VariableUse:
+          inner:
+            kind: VariableUse
       - Fqn:
           inner:
             kind: FullyQualifiedName
@@ -1091,6 +1114,9 @@ PrimaryExpression:
       - Literal:
           inner:
             kind: Literal
+      - VariableUse:
+          inner:
+            kind: VariableUse
       - Fqn:
           inner:
             kind: FullyQualifiedName
diff --git a/src/parser/deimos.pest b/src/parser/deimos.pest
index 81cf3b8..4694984 100644
--- a/src/parser/deimos.pest
+++ b/src/parser/deimos.pest
@@ -542,7 +542,7 @@ VariableDeclaration = {
 }
 
 AssignmentStatement = {
-      Expression
+      LValue
     ~ "="
     ~ Expression
 }
@@ -593,6 +593,24 @@ ForStatement = {
     ~ End
 }
 
+// LValue
+
+LValue = {
+      VariableUse
+    ~ LValueSuffix*
+}
+
+LValueSuffix = {
+      ObjectProperty
+    | ObjectIndex
+}
+
+// Variable Use
+
+VariableUse = {
+      Identifier
+}
+
 // Expressions
 
 Expression = {
@@ -741,6 +759,7 @@ ObjectIndex = {
 
 PrimaryExpression = {
       Literal
+    | VariableUse
     | FullyQualifiedName
     | Closure
     | ListExpression