allow importing global variables, get rid of functions and aliases field of transpiler

src/lib.rs

@@ -115,9 +115,6 @@ pub fn parse(
 
 /// Transpiles the given source code into a shulkerbox [`Datapack`].
 ///
-/// # Parameters:
-/// - `script_paths`: A list of tuples containing the identifier and the path of each script file.
-///
 /// # Errors
 /// - If an error occurs during [`parse()`]
 /// - If an error occurs while transpiling the source code.
@@ -164,15 +161,7 @@ where
 
             Ok(program)
         })
-        .collect::<Vec<_>>();
-
-    if programs.iter().any(Result::is_err) {
-        return Err(programs.into_iter().find_map(Result::err).unwrap());
-    }
-    let programs = programs
-        .into_iter()
-        .filter_map(Result::ok)
-        .collect::<Vec<_>>();
+        .collect::<Result<Vec<_>>>()?;
 
     tracing::info!("Transpiling the source code.");
 

src/semantic/mod.rs

@@ -61,7 +61,7 @@ fn get_global_scope(declarations: &[Declaration]) -> SemanticScope<'static> {
     let scope = SemanticScope::new();
 
     for declaration in declarations {
-        declaration.add_to_scope(&scope);
+        declaration.add_to_semantic_scope(&scope);
     }
 
     scope
@@ -83,23 +83,32 @@ impl Namespace {
 }
 
 impl Declaration {
-    fn add_to_scope(&self, scope: &SemanticScope) {
+    fn add_to_semantic_scope(&self, scope: &SemanticScope) {
         match self {
             Self::Function(func) => {
                 let name = func.identifier();
                 scope.set_variable(name.span.str(), VariableType::Function);
             }
-            Self::Import(imp) => match imp.items() {
-                ImportItems::All(_) => {}
-                ImportItems::Named(items) => {
-                    for item in items.elements() {
-                        if scope.get_variable(item.span.str()) != Some(VariableType::Function) {
-                            scope.set_variable(item.span.str(), VariableType::Function);
-                        }
-                    }
-                }
+            Self::GlobalVariable((_, var, _)) => {
+                let name = var.identifier();
+                let var_type = match var {
+                    VariableDeclaration::Array(arr) => match arr.variable_type().keyword {
+                        KeywordKind::Bool => VariableType::BooleanStorageArray,
+                        KeywordKind::Int => VariableType::ScoreboardArray,
+                        _ => unreachable!("variable type is not a valid type"),
                     },
-            Self::Tag(_) => {}
+                    VariableDeclaration::Score(_) => VariableType::Scoreboard,
+                    VariableDeclaration::Tag(_) => VariableType::Tag,
+                    VariableDeclaration::Single(single) => match single.variable_type().keyword {
+                        KeywordKind::Bool => VariableType::BooleanStorage,
+                        KeywordKind::Int => VariableType::ScoreboardValue,
+                        _ => unreachable!("variable type is not a valid type"),
+                    },
+                    VariableDeclaration::ComptimeValue(_) => VariableType::ComptimeValue,
+                };
+                scope.set_variable(name.span.str(), var_type);
+            }
+            Self::Import(_) | Self::Tag(_) => {}
         }
     }
 
@@ -137,6 +146,8 @@ impl Declaration {
                 }
             },
 
+            Self::GlobalVariable((_, var, _)) => var.analyze_semantics(scope, handler),
+
             Self::Tag(_) => Ok(()),
         }
     }
@@ -549,16 +560,26 @@ impl Primary {
             Self::Boolean(_) | Self::Integer(_) | Self::StringLiteral(_) => Ok(()),
             Self::MacroStringLiteral(lit) => lit.analyze_semantics(scope, handler),
             Self::FunctionCall(call) => {
-                if scope.get_variable(call.identifier().span.str()) == Some(VariableType::Function)
-                {
-                    Ok(())
-                } else {
+                let var = scope.get_variable(call.identifier().span.str());
+                var.map_or_else(
+                    || {
                         let err = error::Error::UnknownIdentifier(UnknownIdentifier {
                             identifier: call.identifier().span.clone(),
                         });
                         handler.receive(err.clone());
                         Err(err)
+                    },
+                    |var| match var {
+                        VariableType::Function | VariableType::InternalFunction => Ok(()),
+                        _ => {
+                            let err = error::Error::UnexpectedExpression(UnexpectedExpression(
+                                Expression::Primary(self.clone()),
+                            ));
+                            handler.receive(err.clone());
+                            Err(err)
                         }
+                    },
+                )
             }
             Self::Indexed(indexed) => {
                 if let Self::Identifier(ident) = indexed.object().as_ref() {

src/syntax/syntax_tree/declaration.rs

@@ -23,7 +23,10 @@ use crate::{
     },
 };
 
-use super::{statement::Block, Annotation, ConnectedList, DelimitedList};
+use super::{
+    statement::{Block, VariableDeclaration},
+    Annotation, ConnectedList, DelimitedList,
+};
 
 /// Represents a declaration in the syntax tree.
 ///
@@ -33,6 +36,8 @@ use super::{statement::Block, Annotation, ConnectedList, DelimitedList};
 /// Declaration:
 ///     Function
 ///     | Import
+///     | Tag
+///     | ('pub'? VariableDeclaration ';')
 ///   ;
 /// ```
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
@@ -41,6 +46,7 @@ pub enum Declaration {
     Function(Function),
     Import(Import),
     Tag(Tag),
+    GlobalVariable((Option<Keyword>, VariableDeclaration, Punctuation)),
 }
 
 impl SourceElement for Declaration {
@@ -49,6 +55,11 @@ impl SourceElement for Declaration {
             Self::Function(function) => function.span(),
             Self::Import(import) => import.span(),
             Self::Tag(tag) => tag.span(),
+            Self::GlobalVariable((pub_kw, variable, semicolon)) => pub_kw
+                .as_ref()
+                .map_or_else(|| variable.span(), SourceElement::span)
+                .join(&semicolon.span)
+                .expect("invalid declaration span"),
         }
     }
 }
@@ -59,13 +70,17 @@ impl Declaration {
     /// # Errors
     /// - if the annotation is invalid for the target declaration.
     pub fn with_annotation(self, annotation: Annotation) -> ParseResult<Self> {
-        #[expect(clippy::single_match_else)]
         match self {
             Self::Function(mut function) => {
                 function.annotations.push_front(annotation);
 
                 Ok(Self::Function(function))
             }
+            Self::GlobalVariable((pub_kw, var, semi)) => {
+                let var_with_annotation = var.with_annotation(annotation)?;
+
+                Ok(Self::GlobalVariable((pub_kw, var_with_annotation, semi)))
+            }
             _ => {
                 let err = Error::InvalidAnnotation(InvalidAnnotation {
                     annotation: annotation.assignment.identifier.span,
@@ -342,11 +357,19 @@ impl Parser<'_> {
             Reading::Atomic(Token::Keyword(pub_keyword))
                 if pub_keyword.keyword == KeywordKind::Pub =>
             {
-                let function = self.parse_function(handler)?;
-
+                if let Ok(function) = self.try_parse(|parser| parser.parse_function(&VoidHandler)) {
                     tracing::trace!("Parsed function '{:?}'", function.identifier.span.str());
 
                     Ok(Declaration::Function(function))
+                } else {
+                    // eat the pub keyword
+                    self.forward();
+
+                    let var = self.parse_variable_declaration(handler)?;
+                    let semi = self.parse_punctuation(';', true, handler)?;
+
+                    Ok(Declaration::GlobalVariable((Some(pub_keyword), var, semi)))
+                }
             }
 
             // parse annotations
@@ -457,6 +480,18 @@ impl Parser<'_> {
                 }))
             }
 
+            Reading::Atomic(Token::Keyword(keyword))
+                if matches!(
+                    keyword.keyword,
+                    KeywordKind::Int | KeywordKind::Bool | KeywordKind::Val
+                ) =>
+            {
+                let var = self.parse_variable_declaration(handler)?;
+                let semi = self.parse_punctuation(';', true, handler)?;
+
+                Ok(Declaration::GlobalVariable((None, var, semi)))
+            }
+
             unexpected => {
                 // make progress
                 self.forward();

src/transpile/expression.rs

@@ -358,11 +358,12 @@ impl Primary {
                     })
                 },
                 |var| match var.as_ref() {
-                    VariableData::ComptimeValue { value } => {
-                        value.read().unwrap().clone().ok_or_else(|| NotComptime {
+                    VariableData::ComptimeValue {
+                        value,
+                        read_only: _,
+                    } => value.read().unwrap().clone().ok_or_else(|| NotComptime {
                         expression: ident.span.clone(),
-                        })
-                    }
+                    }),
                     _ => Err(NotComptime {
                         expression: self.span(),
                     }),
@@ -1276,6 +1277,7 @@ impl Transpiler {
         }
     }
 
+    #[expect(clippy::too_many_lines)]
     fn transpile_scoreboard_operation(
         &mut self,
         binary: &Binary,
@@ -1303,6 +1305,15 @@ impl Transpiler {
             scope,
             handler,
         )?;
+
+        let (right_cmds, rhs_score) =
+            if let Ok(ComptimeValue::Integer(int)) = right.comptime_eval(scope, handler) {
+                self.initialize_constant_score(int);
+                (
+                    Vec::new(),
+                    ("shu_constants", std::borrow::Cow::Owned(int.to_string())),
+                )
+            } else {
                 let right_cmds = self.transpile_expression(
                     right,
                     &DataLocation::ScoreboardValue {
@@ -1313,10 +1324,19 @@ impl Transpiler {
                     handler,
                 )?;
 
+                (
+                    right_cmds,
+                    (
+                        temp_objective.as_str(),
+                        std::borrow::Cow::Borrowed(&temp_locations[1]),
+                    ),
+                )
+            };
+
         let calc_cmds = {
             let (target_objective, target) = score_target_location;
-            let source = &temp_locations[1];
-            let source_objective = &temp_objective;
+            let source = rhs_score.1.as_ref();
+            let source_objective = rhs_score.0;
 
             let operation = match operator {
                 BinaryOperator::Add(_) => "+=",

src/transpile/function.rs

@@ -1,6 +1,6 @@
 use chksum_md5 as md5;
 use enum_as_inner::EnumAsInner;
-use std::{collections::BTreeMap, sync::Arc};
+use std::{borrow::ToOwned, collections::BTreeMap, sync::Arc};
 
 use shulkerbox::datapack::{Command, Execute};
 
@@ -48,31 +48,16 @@ impl Transpiler {
         handler: &impl Handler<base::Error>,
     ) -> TranspileResult<(String, TranspiledFunctionArguments)> {
         let program_identifier = identifier_span.source_file().identifier();
-        let program_query = (
-            program_identifier.to_string(),
-            identifier_span.str().to_string(),
-        );
-        let alias_query = self.aliases.get(&program_query).cloned();
-        let already_transpiled = scope
-            .get_variable(identifier_span.str())
+        let function = scope.get_variable(identifier_span.str());
+        let already_transpiled = function
+            .as_ref()
             .expect("called function should be in scope")
             .as_ref()
             .as_function()
-            .map(|(_, path)| path.get().is_some())
+            .map(|(_, path, _)| path.get().is_some())
             .expect("called variable should be of type function");
 
-        let function_data = scope
-            .get_variable(identifier_span.str())
-            .or_else(|| {
-                alias_query
-                    .clone()
-                    .and_then(|(alias_program_identifier, alias_function_name)| {
-                        self.scopes
-                            .get(&alias_program_identifier)
-                            .and_then(|s| s.get_variable(&alias_function_name))
-                    })
-            })
-            .ok_or_else(|| {
+        let function_data = function.ok_or_else(|| {
             let error = TranspileError::MissingFunctionDeclaration(
                 MissingFunctionDeclaration::from_scope(identifier_span.clone(), scope),
             );
@@ -83,6 +68,7 @@ impl Transpiler {
         let VariableData::Function {
             function_data,
             path: function_path,
+            function_scope,
         } = function_data.as_ref()
         else {
             unreachable!("must be of correct type, otherwise errored out before");
@@ -134,8 +120,6 @@ impl Transpiler {
 
             function_path.set(function_location.clone()).unwrap();
 
-            let function_scope = Scope::with_parent(scope);
-
             for (i, param) in function_data.parameters.iter().enumerate() {
                 let param_str = param.identifier().span.str();
                 match param.variable_type() {
@@ -181,7 +165,7 @@ impl Transpiler {
             }
 
             let commands =
-                self.transpile_function(&statements, program_identifier, &function_scope, handler)?;
+                self.transpile_function(&statements, program_identifier, function_scope, handler)?;
 
             let namespace = self.datapack.namespace_mut(&function_data.namespace);
 

src/transpile/lua.rs

@@ -266,7 +266,10 @@ mod enabled {
                         .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
                     Value::Table(table)
                 }
-                Some(VariableData::ComptimeValue { value }) => {
+                Some(VariableData::ComptimeValue {
+                    value,
+                    read_only: _,
+                }) => {
                     let value = value.read().unwrap();
                     match &*value {
                         Some(ComptimeValue::Boolean(b)) => Value::Boolean(*b),

src/transpile/transpiler.rs

@@ -1,7 +1,7 @@
 //! Transpiler for `Shulkerscript`
 
 use std::{
-    collections::{BTreeMap, HashMap, HashSet},
+    collections::{BTreeMap, HashSet},
     ops::Deref,
     sync::{Arc, OnceLock},
 };
@@ -40,11 +40,7 @@ pub struct Transpiler {
     pub(super) initialized_constant_scores: HashSet<i64>,
     pub(super) temp_counter: usize,
     /// Top-level [`Scope`] for each program identifier
-    pub(super) scopes: BTreeMap<String, Arc<Scope<'static>>>,
-    /// Key: (program identifier, function name)
-    pub(super) functions: BTreeMap<(String, String), FunctionData>,
-    /// Key: alias, Value: target
-    pub(super) aliases: HashMap<(String, String), (String, String)>,
+    pub(super) scopes: BTreeMap<String, Arc<Scope>>,
 }
 
 impl Transpiler {
@@ -59,8 +55,6 @@ impl Transpiler {
             initialized_constant_scores: HashSet::new(),
             temp_counter: 0,
             scopes: BTreeMap::new(),
-            functions: BTreeMap::new(),
-            aliases: HashMap::new(),
         }
     }
 
@@ -75,7 +69,11 @@ impl Transpiler {
         handler: &impl Handler<base::Error>,
     ) -> Result<Datapack, TranspileError> {
         tracing::trace!("Transpiling program declarations");
+
+        let mut aliases = Vec::new();
+
         for program in programs {
+            let mut program_aliases = BTreeMap::new();
             let program_identifier = program
                 .namespace()
                 .span()
@@ -84,17 +82,48 @@ impl Transpiler {
                 .clone();
             let scope = self
                 .scopes
-                .entry(program_identifier)
+                .entry(program_identifier.clone())
                 .or_insert_with(Scope::with_internal_functions)
                 .to_owned();
-            self.transpile_program_declarations(program, &scope, handler);
+            self.transpile_program_declarations(program, &mut program_aliases, &scope, handler)?;
+            aliases.push((scope.clone(), program_aliases));
+        }
+
+        for (scope, program_aliases) in aliases {
+            for (alias_name, (alias_program_identifier, actual_name)) in program_aliases {
+                if let Some(alias_scope) = self.scopes.get(&alias_program_identifier) {
+                    if let Some(var_data) = alias_scope.get_variable(&actual_name) {
+                        scope.set_arc_variable(&alias_name, var_data);
+                    } else {
+                        tracing::error!(
+                            "Importing a non-existent variable: {} from {}",
+                            actual_name,
+                            alias_program_identifier
+                        );
+                    }
+                } else {
+                    tracing::error!(
+                        "Importing from a non-existent program: {}",
+                        alias_program_identifier
+                    );
+                }
+            }
         }
 
         let mut always_transpile_functions = Vec::new();
 
         {
-            let functions = &mut self.functions;
-            for (_, data) in functions.iter() {
+            let functions = self.scopes.iter().flat_map(|(_, scope)| {
+                scope
+                    .get_local_variables()
+                    .read()
+                    .unwrap()
+                    .values()
+                    .filter_map(|data| data.as_function().map(|(data, _, _)| data))
+                    .cloned()
+                    .collect::<Vec<_>>()
+            });
+            for data in functions {
                 let always_transpile_function = data.annotations.contains_key("tick")
                     || data.annotations.contains_key("load")
                     || data.annotations.contains_key("deobfuscate");
@@ -141,25 +170,28 @@ impl Transpiler {
     fn transpile_program_declarations(
         &mut self,
         program: &ProgramFile,
+        program_aliases: &mut BTreeMap<String, (String, String)>,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
-    ) {
+    ) -> TranspileResult<()> {
         let namespace = program.namespace();
 
         for declaration in program.declarations() {
-            self.transpile_declaration(declaration, namespace, scope, handler);
+            self.transpile_declaration(declaration, namespace, program_aliases, scope, handler)?;
         }
+
+        Ok(())
     }
 
     /// Transpiles the given declaration.
-    #[allow(clippy::needless_pass_by_ref_mut)]
     fn transpile_declaration(
         &mut self,
         declaration: &Declaration,
         namespace: &Namespace,
+        program_aliases: &mut BTreeMap<String, (String, String)>,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
-    ) {
+    ) -> TranspileResult<()> {
         let program_identifier = declaration.span().source_file().identifier().clone();
         match declaration {
             Declaration::Function(function) => {
@@ -195,19 +227,18 @@ impl Transpiler {
                 scope.set_variable(
                     &name,
                     VariableData::Function {
-                        function_data: function_data.clone(),
+                        function_data,
                         path: OnceLock::new(),
+                        function_scope: scope.clone(),
                     },
                 );
-                self.functions
-                    .insert((program_identifier, name), function_data);
             }
             Declaration::Import(import) => {
                 let path = import.module().str_content();
                 let import_identifier =
                     super::util::calculate_import_identifier(&program_identifier, path);
 
-                let aliases = &mut self.aliases;
+                // let aliases = &mut self.aliases;
 
                 match import.items() {
                     ImportItems::All(_) => {
@@ -218,8 +249,8 @@ impl Transpiler {
                     ImportItems::Named(list) => {
                         for item in list.elements() {
                             let name = item.span.str();
-                            aliases.insert(
-                                (program_identifier.clone(), name.to_string()),
+                            program_aliases.insert(
+                                name.to_string(),
                                 (import_identifier.clone(), name.to_string()),
                             );
                         }
@@ -241,9 +272,21 @@ impl Transpiler {
                 if tag.replace().is_some() {
                     sb_tag.set_replace(true);
                 }
-                // TODO: handle global variables
+            }
+            Declaration::GlobalVariable((_, declaration, _)) => {
+                let setup_variable_cmds = self.transpile_variable_declaration(
+                    declaration,
+                    true,
+                    &program_identifier,
+                    scope,
+                    handler,
+                )?;
+
+                self.setup_cmds.extend(setup_variable_cmds);
             }
         };
+
+        Ok(())
     }
 
     pub(super) fn transpile_statement(
@@ -264,7 +307,7 @@ impl Transpiler {
                 unreachable!("Only literal commands are allowed in functions at this time.")
             }
             Statement::ExecuteBlock(execute) => {
-                let child_scope = Scope::with_parent(scope);
+                let child_scope = Scope::with_parent(scope.clone());
                 Ok(self.transpile_execute_block(
                     execute,
                     program_identifier,
@@ -277,7 +320,7 @@ impl Transpiler {
                 Ok(vec![Command::Comment(content.to_string())])
             }
             Statement::Grouping(group) => {
-                let child_scope = Scope::with_parent(scope);
+                let child_scope = Scope::with_parent(scope.clone());
                 let statements = group.block().statements();
                 let mut errors = Vec::new();
                 let commands = statements
@@ -317,9 +360,14 @@ impl Transpiler {
                         Err(error)
                     }
                 },
-                SemicolonStatement::VariableDeclaration(decl) => {
-                    self.transpile_variable_declaration(decl, program_identifier, scope, handler)
-                }
+                SemicolonStatement::VariableDeclaration(decl) => self
+                    .transpile_variable_declaration(
+                        decl,
+                        false,
+                        program_identifier,
+                        scope,
+                        handler,
+                    ),
                 SemicolonStatement::Assignment(assignment) => self.transpile_assignment(
                     TranspileAssignmentTarget::from(assignment.destination()),
                     assignment.expression(),
@@ -344,8 +392,10 @@ impl Transpiler {
             }
             Expression::Primary(Primary::Identifier(ident)) => {
                 match scope.get_variable(ident.span.str()).as_deref() {
-                    Some(VariableData::ComptimeValue { value }) => {
-                        value.read().unwrap().as_ref().map_or_else(
+                    Some(VariableData::ComptimeValue {
+                        value,
+                        read_only: _,
+                    }) => value.read().unwrap().as_ref().map_or_else(
                         || {
                             let error = TranspileError::MissingValue(MissingValue {
                                 expression: ident.span.clone(),
@@ -360,8 +410,7 @@ impl Transpiler {
                             );
                             Ok(vec![cmd])
                         },
-                        )
-                    }
+                    ),
                     Some(_) => {
                         let error = TranspileError::UnexpectedExpression(UnexpectedExpression(
                             expression.clone(),

src/transpile/variables.rs

@@ -49,6 +49,8 @@ pub enum VariableData {
         function_data: FunctionData,
         /// The path to the function once it is generated.
         path: OnceLock<String>,
+        /// The scope of the function.
+        function_scope: Arc<Scope>,
     },
     /// A macro function parameter.
     MacroParameter {
@@ -104,6 +106,8 @@ pub enum VariableData {
     ComptimeValue {
         /// The value.
         value: Arc<RwLock<Option<ComptimeValue>>>,
+        /// Whether the value is read-only.
+        read_only: bool,
     },
 }
 
@@ -129,9 +133,9 @@ impl<'a> From<&'a AssignmentDestination> for TranspileAssignmentTarget<'a> {
 /// A scope that stores variables.
 #[cfg(feature = "shulkerbox")]
 #[derive(Default)]
-pub struct Scope<'a> {
+pub struct Scope {
     /// Parent scope where variables are inherited from.
-    parent: Option<&'a Arc<Self>>,
+    parent: Option<Arc<Self>>,
     /// Variables stored in the scope.
     variables: RwLock<HashMap<String, Arc<VariableData>>>,
     /// How many times the variable has been shadowed in the current scope.
@@ -139,7 +143,7 @@ pub struct Scope<'a> {
 }
 
 #[cfg(feature = "shulkerbox")]
-impl<'a> Scope<'a> {
+impl Scope {
     /// Creates a new scope.
     #[must_use]
     pub fn new() -> Arc<Self> {
@@ -161,7 +165,7 @@ impl<'a> Scope<'a> {
 
     /// Creates a new scope with a parent.
     #[must_use]
-    pub fn with_parent(parent: &'a Arc<Self>) -> Arc<Self> {
+    pub fn with_parent(parent: Arc<Self>) -> Arc<Self> {
         Arc::new(Self {
             parent: Some(parent),
             ..Default::default()
@@ -198,11 +202,17 @@ impl<'a> Scope<'a> {
 
     /// Sets a variable in the scope.
     pub fn set_variable(&self, name: &str, var: VariableData) {
+        self.set_arc_variable(name, Arc::new(var));
+    }
+
+    /// Sets a variable in the scope.
+    /// This function is used to set a variable that is already wrapped in an `Arc`.
+    pub fn set_arc_variable(&self, name: &str, var: Arc<VariableData>) {
         let prev = self
             .variables
             .write()
             .unwrap()
-            .insert(name.to_string(), Arc::new(var));
+            .insert(name.to_string(), var);
         *self
             .shadowed
             .write()
@@ -229,12 +239,12 @@ impl<'a> Scope<'a> {
 
     /// Gets the parent scope.
     pub fn get_parent(&self) -> Option<Arc<Self>> {
-        self.parent.cloned()
+        self.parent.clone()
     }
 }
 
 #[cfg(feature = "shulkerbox")]
-impl Debug for Scope<'_> {
+impl Debug for Scope {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         struct VariableWrapper<'a>(&'a RwLock<HashMap<String, Arc<VariableData>>>);
         impl Debug for VariableWrapper<'_> {
@@ -258,6 +268,7 @@ impl Transpiler {
     pub(super) fn transpile_variable_declaration(
         &mut self,
         declaration: &VariableDeclaration,
+        is_global: bool,
         program_identifier: &str,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
@@ -265,6 +276,7 @@ impl Transpiler {
         match declaration {
             VariableDeclaration::Single(declaration) => self.transpile_single_variable_declaration(
                 declaration,
+                is_global,
                 program_identifier,
                 scope,
                 handler,
@@ -277,6 +289,7 @@ impl Transpiler {
             ),
             VariableDeclaration::Array(declaration) => self.transpile_array_variable_declaration(
                 declaration,
+                is_global,
                 program_identifier,
                 scope,
                 handler,
@@ -307,6 +320,7 @@ impl Transpiler {
                     declaration.identifier().span.str(),
                     VariableData::ComptimeValue {
                         value: Arc::new(RwLock::new(value)),
+                        read_only: is_global,
                     },
                 );
 
@@ -318,6 +332,7 @@ impl Transpiler {
     fn transpile_single_variable_declaration(
         &mut self,
         declaration: &SingleVariableDeclaration,
+        is_global: bool,
         program_identifier: &str,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
@@ -342,7 +357,7 @@ impl Transpiler {
                     declaration.identifier().span.str(),
                     VariableData::ScoreboardValue {
                         objective: name.clone(),
-                        target,
+                        target: target.clone(),
                     },
                 );
             }
@@ -350,25 +365,49 @@ impl Transpiler {
                 scope.set_variable(
                     declaration.identifier().span.str(),
                     VariableData::BooleanStorage {
-                        storage_name: name,
-                        path: target,
+                        storage_name: name.clone(),
+                        path: target.clone(),
                     },
                 );
             }
             _ => unreachable!("no other variable types"),
         }
 
-        declaration.assignment().as_ref().map_or_else(
-            || Ok(Vec::new()),
-            |assignment| {
-                self.transpile_assignment(
+        if let Some(assignment) = declaration.assignment().as_ref() {
+            let cmds = self.transpile_assignment(
                 TranspileAssignmentTarget::Identifier(declaration.identifier()),
                 assignment.expression(),
                 scope,
                 handler,
-                )
-            },
-        )
+            )?;
+            if is_global {
+                let (temp_objective, temp_targets) = self.get_temp_scoreboard_locations(1);
+                let temp_target = &temp_targets[0];
+                let test_cmd = match declaration.variable_type().keyword {
+                    KeywordKind::Int => {
+                        Command::Raw(format!("scoreboard players get {name} {target}"))
+                    }
+                    KeywordKind::Bool => Command::Raw(format!("data get storage {name} {target}")),
+                    _ => unreachable!("no other variable types"),
+                };
+                let test_exists_cmd = Command::Execute(Execute::Store(
+                    format!("success score {temp_target} {temp_objective}").into(),
+                    Box::new(Execute::Run(Box::new(test_cmd))),
+                ));
+                let cond_cmd = Command::Execute(Execute::If(
+                    Condition::Atom(
+                        format!("score {temp_target} {temp_objective} matches 0").into(),
+                    ),
+                    Box::new(Execute::Run(Box::new(Command::Group(cmds)))),
+                    None,
+                ));
+                Ok(vec![test_exists_cmd, cond_cmd])
+            } else {
+                Ok(cmds)
+            }
+        } else {
+            Ok(Vec::new())
+        }
     }
 
     fn transpile_score_variable_declaration(
@@ -411,6 +450,7 @@ impl Transpiler {
     fn transpile_array_variable_declaration(
         &mut self,
         declaration: &ArrayVariableDeclaration,
+        _is_global: bool,
         program_identifier: &str,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
@@ -450,6 +490,7 @@ impl Transpiler {
         declaration.assignment().as_ref().map_or_else(
             || Ok(Vec::new()),
             |assignment| {
+                // TODO: implement global already exists check when array assignments are implemented
                 self.transpile_assignment(
                     TranspileAssignmentTarget::Identifier(declaration.identifier()),
                     assignment.expression(),
@@ -692,7 +733,15 @@ impl Transpiler {
                         return Err(err);
                     }
                 },
-                VariableData::ComptimeValue { value } => {
+                VariableData::ComptimeValue { value, read_only } => {
+                    if *read_only {
+                        let err = TranspileError::AssignmentError(AssignmentError {
+                            identifier: identifier.span(),
+                            message: "Cannot assign to a read-only value.".to_string(),
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
+                    }
                     let comptime_value =
                         expression.comptime_eval(scope, handler).map_err(|err| {
                             let err = TranspileError::NotComptime(err);
@@ -1097,9 +1146,14 @@ impl Transpiler {
                     DataLocation::Storage {
                         storage_name: target_storage_name,
                         path: target_path,
-                        r#type,
+                        r#type: target_type,
                     } => {
-                        if matches!(r#type, StorageType::Boolean) {
+                        if storage_name == target_storage_name
+                            && path == target_path
+                            && r#type == target_type
+                        {
+                            Ok(Vec::new())
+                        } else if matches!(target_type, StorageType::Boolean) {
                             let cmd = Command::Raw(format!(
                                         "data modify storage {target_storage_name} {target_path} set from storage {storage_name} {path}"
                                     ));
@@ -1123,11 +1177,15 @@ impl Transpiler {
                     objective: target_objective,
                     target: target_target,
                 } => {
+                    if objective == target_objective && score_target == target_target {
+                        Ok(Vec::new())
+                    } else {
                         let cmd = Command::Raw(format!(
                             "scoreboard players operation {target_target} {target_objective} = {score_target} {objective}"
                         ));
                         Ok(vec![cmd])
                     }
+                }
                 DataLocation::Storage {
                     storage_name,
                     path,
@@ -1213,7 +1271,7 @@ mod tests {
                 objective: "test".to_string(),
             },
         );
-        let child = Scope::with_parent(&scope);
+        let child = Scope::with_parent(scope);
         if let Some(var) = child.get_variable("test") {
             match var.as_ref() {
                 VariableData::Scoreboard { objective } => assert_eq!(objective, "test"),
@@ -1233,7 +1291,7 @@ mod tests {
                 objective: "test1".to_string(),
             },
         );
-        let child = Scope::with_parent(&scope);
+        let child = Scope::with_parent(scope);
         child.set_variable(
             "test",
             VariableData::Scoreboard {