implement first version of compiler variables

CHANGELOG.md

@@ -21,6 +21,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Change the syntax to set the type of a tag from `tag "[name]" of "[type]"` to `tag<"[type]"> "[name]"`
+    - Remove the keyword `of`
 - Option to deduplicate source files during serialization when using `SerdeWrapper`
 
 ### Removed

src/lexical/token.rs

@@ -48,11 +48,11 @@ pub enum KeywordKind {
     From,
     Import,
     Tag,
-    Of,
     Replace,
     Int,
     Bool,
     Macro,
+    Val,
 }
 
 impl Display for KeywordKind {
@@ -114,11 +114,11 @@ impl KeywordKind {
             Self::From => "from",
             Self::Import => "import",
             Self::Tag => "tag",
-            Self::Of => "of",
             Self::Replace => "replace",
             Self::Int => "int",
             Self::Bool => "bool",
             Self::Macro => "macro",
+            Self::Val => "val",
         }
     }
 

src/semantic/error.rs

@@ -2,10 +2,7 @@
 
 #![allow(missing_docs)]
 
-use std::{collections::HashSet, fmt::Display};
-
-use getset::Getters;
-use itertools::Itertools as _;
+use std::fmt::Display;
 
 use crate::{
     base::{
@@ -14,6 +11,10 @@ use crate::{
     },
     lexical::token::StringLiteral,
     syntax::syntax_tree::expression::Expression,
+    transpile::error::{
+        AssignmentError, IllegalIndexing, MismatchedTypes, MissingFunctionDeclaration,
+        UnknownIdentifier,
+    },
 };
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash, thiserror::Error)]
@@ -31,77 +32,20 @@ pub enum Error {
     UnresolvedMacroUsage(#[from] UnresolvedMacroUsage),
     #[error(transparent)]
     IncompatibleFunctionAnnotation(#[from] IncompatibleFunctionAnnotation),
+    #[error(transparent)]
+    IllegalIndexing(#[from] IllegalIndexing),
+    #[error(transparent)]
+    MismatchedTypes(#[from] MismatchedTypes),
+    #[error(transparent)]
+    UnknownIdentifier(#[from] UnknownIdentifier),
+    #[error(transparent)]
+    AssignmentError(#[from] AssignmentError),
+    #[error("Lua is disabled, but a Lua function was used.")]
+    LuaDisabled,
+    #[error("Other: {0}")]
+    Other(String),
 }
 
-// TODO: remove duplicate error (also in transpile)
-/// An error that occurs when a function declaration is missing.
-#[derive(Debug, Clone, PartialEq, Eq, Hash, Getters)]
-pub struct MissingFunctionDeclaration {
-    #[get = "pub"]
-    span: Span,
-    #[get = "pub"]
-    alternatives: Vec<String>,
-}
-
-impl MissingFunctionDeclaration {
-    #[expect(dead_code)]
-    pub(super) fn from_context(identifier_span: Span, functions: &HashSet<String>) -> Self {
-        let own_name = identifier_span.str();
-        let alternatives = functions
-            .iter()
-            .filter_map(|function_name| {
-                let normalized_distance =
-                    strsim::normalized_damerau_levenshtein(own_name, function_name);
-                (normalized_distance > 0.8
-                    || strsim::damerau_levenshtein(own_name, function_name) < 3)
-                    .then_some((normalized_distance, function_name))
-            })
-            .sorted_by(|a, b| a.0.partial_cmp(&b.0).unwrap_or(std::cmp::Ordering::Equal))
-            .map(|(_, data)| data)
-            .take(8)
-            .cloned()
-            .collect::<Vec<_>>();
-
-        Self {
-            alternatives,
-            span: identifier_span,
-        }
-    }
-}
-
-impl Display for MissingFunctionDeclaration {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        use std::fmt::Write;
-
-        let message = format!(
-            "no matching function declaration found for invocation of function `{}`",
-            self.span.str()
-        );
-        write!(f, "{}", Message::new(Severity::Error, message))?;
-
-        let help_message = if self.alternatives.is_empty() {
-            None
-        } else {
-            let mut message = String::from("did you mean ");
-            for (i, alternative) in self.alternatives.iter().enumerate() {
-                if i > 0 {
-                    message.push_str(", ");
-                }
-                write!(message, "`{alternative}`")?;
-            }
-            Some(message + "?")
-        };
-
-        write!(
-            f,
-            "\n{}",
-            SourceCodeDisplay::new(&self.span, help_message.as_ref())
-        )
-    }
-}
-
-impl std::error::Error for MissingFunctionDeclaration {}
-
 /// An error that occurs when a function declaration is missing.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub struct UnexpectedExpression(pub Expression);

src/semantic/scope.rs

@@ -0,0 +1,97 @@
+use std::{collections::HashMap, sync::RwLock};
+
+/// Type of variable
+#[derive(Clone, Debug, Copy, PartialEq, Eq)]
+pub enum VariableType {
+    /// A function.
+    Function,
+    /// A macro function parameter.
+    MacroParameter,
+    /// A scoreboard.
+    Scoreboard,
+    /// A scoreboard value.
+    ScoreboardValue,
+    /// Multiple values stored in scoreboard.
+    ScoreboardArray,
+    /// A tag applied to entities.
+    Tag,
+    /// A boolean stored in a data storage.
+    BooleanStorage,
+    /// Multiple booleans stored in a data storage array.
+    BooleanStorageArray,
+    /// Compiler internal function.
+    InternalFunction,
+    /// Compiler internal value.
+    ComptimeValue,
+}
+
+/// A scope that stores variables.
+#[derive(Debug, Default)]
+pub struct SemanticScope<'a> {
+    /// Parent scope where variables are inherited from.
+    parent: Option<&'a Self>,
+    /// Variables stored in the scope.
+    variables: RwLock<HashMap<String, VariableType>>,
+}
+
+impl<'a> SemanticScope<'a> {
+    /// Creates a new scope.
+    #[must_use]
+    pub fn new() -> Self {
+        let scope = Self::default();
+
+        scope.set_variable("print", VariableType::InternalFunction);
+
+        scope
+    }
+
+    /// Creates a new scope with a parent.
+    #[must_use]
+    pub fn with_parent(parent: &'a Self) -> Self {
+        Self {
+            parent: Some(parent),
+            ..Default::default()
+        }
+    }
+
+    /// Gets a variable from the scope.
+    pub fn get_variable(&self, name: &str) -> Option<VariableType> {
+        let var = self.variables.read().unwrap().get(name).copied();
+        if var.is_some() {
+            var
+        } else {
+            self.parent
+                .as_ref()
+                .and_then(|parent| parent.get_variable(name))
+        }
+    }
+
+    /// Sets a variable in the scope.
+    pub fn set_variable(&self, name: &str, var: VariableType) {
+        self.variables
+            .write()
+            .unwrap()
+            .insert(name.to_string(), var);
+    }
+
+    /// Gets the variables stored in the current scope.
+    pub fn get_local_variables(&self) -> &RwLock<HashMap<String, VariableType>> {
+        &self.variables
+    }
+
+    /// Gets all variables stored in the scope.
+    ///
+    /// This function does not return a reference to the variables, but clones them.
+    pub fn get_all_variables(&self) -> HashMap<String, VariableType> {
+        let mut variables = self.variables.read().unwrap().clone();
+        if let Some(parent) = self.parent.as_ref() {
+            variables.extend(parent.get_all_variables());
+        }
+        variables
+    }
+
+    /// Gets the parent scope.
+    pub fn get_parent(&self) -> Option<&Self> {
+        self.parent
+    }
+}

src/syntax/syntax_tree/declaration.rs

@@ -253,7 +253,7 @@ impl SourceElement for Import {
 ///
 /// ``` ebnf
 /// TagDeclaration:
-///     'tag' StringLiteral ('of' StringLiteral)? 'replace'? '[' (StringLiteral (',' StringLiteral)*)? ']'
+///     'tag' ('<' StringLiteral '>')? StringLiteral 'replace'? '[' (StringLiteral (',' StringLiteral)*)? ']'
 ///     ;
 /// ```
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
@@ -262,9 +262,9 @@ pub struct Tag {
     #[get = "pub"]
     tag_keyword: Keyword,
     #[get = "pub"]
-    name: StringLiteral,
+    of_type: Option<(Punctuation, StringLiteral, Punctuation)>,
     #[get = "pub"]
-    of_type: Option<(Keyword, StringLiteral)>,
+    name: StringLiteral,
     #[get = "pub"]
     replace: Option<Keyword>,
     #[get = "pub"]
@@ -278,15 +278,15 @@ impl Tag {
         self,
     ) -> (
         Keyword,
+        Option<(Punctuation, StringLiteral, Punctuation)>,
         StringLiteral,
-        Option<(Keyword, StringLiteral)>,
         Option<Keyword>,
         DelimitedList<StringLiteral>,
     ) {
         (
             self.tag_keyword,
-            self.name,
             self.of_type,
+            self.name,
             self.replace,
             self.entries,
         )
@@ -299,7 +299,7 @@ impl Tag {
 
         self.of_type
             .as_ref()
-            .map_or(TagType::Function, |(_, tag_type)| {
+            .map_or(TagType::Function, |(_, tag_type, _)| {
                 match tag_type.str_content().as_ref() {
                     "function" => TagType::Function,
                     "block" => TagType::Block,
@@ -419,18 +419,24 @@ impl Parser<'_> {
                 // eat the tag keyword
                 self.forward();
 
+                let of_type = match self.stop_at_significant() {
+                    Reading::Atomic(Token::Punctuation(punc)) if punc.punctuation == '<' => {
+                        // eat the open bracket
+                        self.forward();
+
+                        let of_type = self.parse_string_literal(handler)?;
+
+                        // eat the close bracket
+                        let closing = self.parse_punctuation('>', true, handler)?;
+
+                        Some((punc, of_type, closing))
+                    }
+                    _ => None,
+                };
+
                 // parse the name
                 let name = self.parse_string_literal(handler)?;
 
-                let of_type = self
-                    .try_parse(|parser| {
-                        let of_keyword = parser.parse_keyword(KeywordKind::Of, &VoidHandler)?;
-                        let of_type = parser.parse_string_literal(handler)?;
-
-                        Ok((of_keyword, of_type))
-                    })
-                    .ok();
-
                 let replace = self
                     .try_parse(|parser| parser.parse_keyword(KeywordKind::Replace, &VoidHandler))
                     .ok();
@@ -444,8 +450,8 @@ impl Parser<'_> {
 
                 Ok(Declaration::Tag(Tag {
                     tag_keyword,
-                    name,
                     of_type,
+                    name,
                     replace,
                     entries,
                 }))

src/syntax/syntax_tree/expression.rs

@@ -247,6 +247,14 @@ impl SourceElement for Parenthesized {
     }
 }
 
+impl std::ops::Deref for Parenthesized {
+    type Target = Expression;
+
+    fn deref(&self) -> &Self::Target {
+        &self.expression
+    }
+}
+
 /// Represents a indexed expression in the syntax tree.
 ///
 /// Syntax Synopsis:    

src/syntax/syntax_tree/statement.rs

@@ -325,6 +325,7 @@ pub enum VariableDeclaration {
     Array(ArrayVariableDeclaration),
     Score(ScoreVariableDeclaration),
     Tag(TagVariableDeclaration),
+    ComptimeValue(ComptimeValueDeclaration),
 }
 
 impl SourceElement for VariableDeclaration {
@@ -334,6 +335,7 @@ impl SourceElement for VariableDeclaration {
             Self::Array(declaration) => declaration.span(),
             Self::Score(declaration) => declaration.span(),
             Self::Tag(declaration) => declaration.span(),
+            Self::ComptimeValue(declaration) => declaration.span(),
         }
     }
 }
@@ -347,6 +349,7 @@ impl VariableDeclaration {
             Self::Array(declaration) => &declaration.identifier,
             Self::Score(declaration) => &declaration.identifier,
             Self::Tag(declaration) => &declaration.identifier,
+            Self::ComptimeValue(declaration) => &declaration.identifier,
         }
     }
 
@@ -358,6 +361,7 @@ impl VariableDeclaration {
             Self::Array(declaration) => &declaration.variable_type,
             Self::Score(declaration) => &declaration.int_keyword,
             Self::Tag(declaration) => &declaration.bool_keyword,
+            Self::ComptimeValue(declaration) => &declaration.val_keyword,
         }
     }
 
@@ -383,6 +387,14 @@ impl VariableDeclaration {
                 declaration.annotations.push_front(annotation);
                 Ok(Self::Tag(declaration))
             }
+            Self::ComptimeValue(_) => {
+                let err = Error::InvalidAnnotation(InvalidAnnotation {
+                    annotation: annotation.assignment.identifier.span,
+                    target: "comptime values".to_string(),
+                });
+
+                Err(err)
+            }
         }
     }
 }
@@ -681,6 +693,53 @@ impl TagVariableDeclaration {
     }
 }
 
+/// Represents a compile time value declaration in the syntax tree.
+///
+/// Syntax Synopsis:
+///
+/// ```ebnf
+/// ComptimeValueDeclaration:
+///     'val' identifier VariableDeclarationAssignment?
+/// ```
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Getters)]
+pub struct ComptimeValueDeclaration {
+    /// The type of the variable.
+    #[get = "pub"]
+    val_keyword: Keyword,
+    /// The identifier of the variable.
+    #[get = "pub"]
+    identifier: Identifier,
+    /// The optional assignment of the variable.
+    #[get = "pub"]
+    assignment: Option<VariableDeclarationAssignment>,
+    /// The annotations of the variable declaration.
+    #[get = "pub"]
+    annotations: VecDeque<Annotation>,
+}
+
+impl SourceElement for ComptimeValueDeclaration {
+    fn span(&self) -> Span {
+        self.val_keyword
+            .span()
+            .join(
+                &self
+                    .assignment
+                    .as_ref()
+                    .map_or_else(|| self.identifier.span(), SourceElement::span),
+            )
+            .expect("The span of the single variable declaration is invalid.")
+    }
+}
+
+impl ComptimeValueDeclaration {
+    /// Dissolves the [`ComptimeValueDeclaration`] into its components.
+    #[must_use]
+    pub fn dissolve(self) -> (Keyword, Identifier, Option<VariableDeclarationAssignment>) {
+        (self.val_keyword, self.identifier, self.assignment)
+    }
+}
+
 /// Represents an assignment in the syntax tree.
 ///
 /// Syntax Synopsis:
@@ -883,7 +942,10 @@ impl Parser<'_> {
     ) -> ParseResult<Semicolon> {
         let statement = match self.stop_at_significant() {
             Reading::Atomic(Token::Keyword(keyword))
-                if matches!(keyword.keyword, KeywordKind::Int | KeywordKind::Bool) =>
+                if matches!(
+                    keyword.keyword,
+                    KeywordKind::Int | KeywordKind::Bool | KeywordKind::Val
+                ) =>
             {
                 self.parse_variable_declaration(handler)
                     .map(SemicolonStatement::VariableDeclaration)
@@ -895,18 +957,20 @@ impl Parser<'_> {
                     let destination = {
                         let identifier = p.parse_identifier(&VoidHandler)?;
 
-                        if let Ok(tree) = p.step_into(
-                            Delimiter::Bracket,
-                            |pp| pp.parse_expression(&VoidHandler),
-                            &VoidHandler,
-                        ) {
-                            let open = tree.open;
-                            let close = tree.close;
-                            let expression = tree.tree?;
+                        match p.stop_at_significant() {
+                            Reading::IntoDelimited(punc) if punc.punctuation == '[' => {
+                                let tree = p.step_into(
+                                    Delimiter::Bracket,
+                                    |pp| pp.parse_expression(&VoidHandler),
+                                    &VoidHandler,
+                                )?;
+                                let open = tree.open;
+                                let close = tree.close;
+                                let expression = tree.tree?;
 
-                            AssignmentDestination::Indexed(identifier, open, expression, close)
-                        } else {
-                            AssignmentDestination::Identifier(identifier)
+                                AssignmentDestination::Indexed(identifier, open, expression, close)
+                            }
+                            _ => AssignmentDestination::Identifier(identifier),
                         }
                     };
                     let equals = p.parse_punctuation('=', true, &VoidHandler)?;
@@ -948,7 +1012,10 @@ impl Parser<'_> {
 
         let variable_type = match self.stop_at_significant() {
             Reading::Atomic(Token::Keyword(keyword))
-                if matches!(keyword.keyword, KeywordKind::Int | KeywordKind::Bool) =>
+                if matches!(
+                    keyword.keyword,
+                    KeywordKind::Int | KeywordKind::Bool | KeywordKind::Val
+                ) =>
             {
                 self.forward();
                 keyword
@@ -983,7 +1050,10 @@ impl Parser<'_> {
         let identifier = self.parse_identifier(handler)?;
 
         match self.stop_at_significant() {
-            Reading::IntoDelimited(punc) if punc.punctuation == '[' => {
+            Reading::IntoDelimited(punc)
+                if punc.punctuation == '['
+                    && matches!(variable_type.keyword, KeywordKind::Int | KeywordKind::Bool) =>
+            {
                 let tree = self.step_into(
                     Delimiter::Bracket,
                     |p| {
@@ -1071,12 +1141,23 @@ impl Parser<'_> {
                 let expression = self.parse_expression(handler)?;
                 let assignment = VariableDeclarationAssignment { equals, expression };
 
-                Ok(VariableDeclaration::Single(SingleVariableDeclaration {
-                    variable_type,
-                    identifier,
-                    assignment: Some(assignment),
-                    annotations: VecDeque::new(),
-                }))
+                if variable_type.keyword == KeywordKind::Val {
+                    Ok(VariableDeclaration::ComptimeValue(
+                        ComptimeValueDeclaration {
+                            val_keyword: variable_type,
+                            identifier,
+                            assignment: Some(assignment),
+                            annotations: VecDeque::new(),
+                        },
+                    ))
+                } else {
+                    Ok(VariableDeclaration::Single(SingleVariableDeclaration {
+                        variable_type,
+                        identifier,
+                        assignment: Some(assignment),
+                        annotations: VecDeque::new(),
+                    }))
+                }
             }
             // SingleVariableDeclaration without Assignment
             _ => Ok(VariableDeclaration::Single(SingleVariableDeclaration {

src/syntax/syntax_tree/statement/execute_block.rs

@@ -1,7 +1,5 @@
 //! Execute block statement syntax tree.
 
-use std::collections::HashSet;
-
 use derive_more::From;
 use enum_as_inner::EnumAsInner;
 use getset::Getters;
@@ -998,10 +996,10 @@ pub trait ExecuteBlockHeadItem {
     #[expect(clippy::missing_errors_doc)]
     fn analyze_semantics(
         &self,
-        macro_names: &HashSet<String>,
+        scope: &crate::semantic::SemanticScope,
         handler: &impl Handler<base::Error>,
     ) -> Result<(), crate::semantic::error::Error> {
-        self.selector().analyze_semantics(macro_names, handler)
+        self.selector().analyze_semantics(scope, handler)
     }
 }
 

src/transpile/error.rs

@@ -44,6 +44,10 @@ pub enum TranspileError {
     MissingValue(#[from] MissingValue),
     #[error(transparent)]
     IllegalIndexing(#[from] IllegalIndexing),
+    #[error(transparent)]
+    InvalidArgument(#[from] InvalidArgument),
+    #[error(transparent)]
+    NotComptime(#[from] NotComptime),
 }
 
 /// The result of a transpilation operation.
@@ -52,8 +56,10 @@ pub type TranspileResult<T> = Result<T, TranspileError>;
 /// An error that occurs when a function declaration is missing.
 #[derive(Debug, Clone, PartialEq, Eq, Getters)]
 pub struct MissingFunctionDeclaration {
+    /// The span of the identifier that is missing.
     #[get = "pub"]
     span: Span,
+    /// Possible alternatives for the missing function declaration.
     #[get = "pub"]
     alternatives: Vec<FunctionData>,
 }
@@ -127,11 +133,26 @@ impl Display for MissingFunctionDeclaration {
 
 impl std::error::Error for MissingFunctionDeclaration {}
 
+impl std::hash::Hash for MissingFunctionDeclaration {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        self.span.hash(state);
+        for alternative in &self.alternatives {
+            alternative.identifier_span.hash(state);
+            alternative.namespace.hash(state);
+            alternative.parameters.hash(state);
+            alternative.public.hash(state);
+            alternative.statements.hash(state);
+        }
+    }
+}
+
 /// An error that occurs when a function declaration is missing.
 #[allow(clippy::module_name_repetitions)]
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct LuaRuntimeError {
+    /// The span of the code block that caused the error.
     pub code_block: Span,
+    /// The error message of the Lua runtime.
     pub error_message: String,
 }
 
@@ -155,6 +176,8 @@ impl std::error::Error for LuaRuntimeError {}
 
 #[cfg(feature = "lua")]
 impl LuaRuntimeError {
+    /// Creates a new Lua runtime error from an mlua error.
+    #[must_use]
     pub fn from_lua_err(err: &mlua::Error, span: Span) -> Self {
         let err_string = err.to_string();
         Self {
@@ -168,9 +191,13 @@ impl LuaRuntimeError {
 }
 
 /// An error that occurs when an annotation has an illegal content.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Getters)]
 pub struct IllegalAnnotationContent {
+    /// The span of the annotation.
+    #[get = "pub"]
     pub annotation: Span,
+    /// The error message.
+    #[get = "pub"]
     pub message: String,
 }
 
@@ -194,9 +221,13 @@ impl Display for IllegalAnnotationContent {
 impl std::error::Error for IllegalAnnotationContent {}
 
 /// An error that occurs when an expression can not evaluate to the wanted type.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Getters)]
 pub struct MismatchedTypes {
+    /// The expression that can not evaluate to the wanted type.
+    #[get = "pub"]
     pub expression: Span,
+    /// The expected type.
+    #[get = "pub"]
     pub expected_type: ExpectedType,
 }
 
@@ -216,9 +247,13 @@ impl Display for MismatchedTypes {
 impl std::error::Error for MismatchedTypes {}
 
 /// An error that occurs when an expression can not evaluate to the wanted type.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Getters)]
 pub struct FunctionArgumentsNotAllowed {
+    /// The arguments that are not allowed.
+    #[get = "pub"]
     pub arguments: Span,
+    /// The error message.
+    #[get = "pub"]
     pub message: String,
 }
 
@@ -237,9 +272,13 @@ impl Display for FunctionArgumentsNotAllowed {
 impl std::error::Error for FunctionArgumentsNotAllowed {}
 
 /// An error that occurs when an expression can not evaluate to the wanted type.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Getters)]
 pub struct AssignmentError {
+    /// The identifier that is assigned to.
+    #[get = "pub"]
     pub identifier: Span,
+    /// The error message.
+    #[get = "pub"]
     pub message: String,
 }
 
@@ -258,8 +297,10 @@ impl Display for AssignmentError {
 impl std::error::Error for AssignmentError {}
 
 /// An error that occurs when an unknown identifier is used.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Getters)]
 pub struct UnknownIdentifier {
+    /// The unknown identifier.
+    #[get = "pub"]
     pub identifier: Span,
 }
 
@@ -285,8 +326,10 @@ impl Display for UnknownIdentifier {
 impl std::error::Error for UnknownIdentifier {}
 
 /// An error that occurs when there is a value expected but none provided.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Getters)]
 pub struct MissingValue {
+    /// The expression that is missing a value.
+    #[get = "pub"]
     pub expression: Span,
 }
 
@@ -312,9 +355,13 @@ impl Display for MissingValue {
 impl std::error::Error for MissingValue {}
 
 /// An error that occurs when an indexing operation is not permitted.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Getters)]
 pub struct IllegalIndexing {
+    /// The reason why the indexing operation is not permitted.
+    #[get = "pub"]
     pub reason: IllegalIndexingReason,
+    /// The expression that is the reason for the indexing being illegal.
+    #[get = "pub"]
     pub expression: Span,
 }
 
@@ -333,11 +380,24 @@ impl Display for IllegalIndexing {
 impl std::error::Error for IllegalIndexing {}
 
 /// The reason why an indexing operation is not permitted.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum IllegalIndexingReason {
+    /// The expression is not an identifier.
     NotIdentifier,
-    InvalidComptimeType { expected: ExpectedType },
-    IndexOutOfBounds { index: usize, length: usize },
+    /// The expression cannot be indexed.
+    NotIndexable,
+    /// The expression can only be indexed with a specific type that can be evaluated at compile time.
+    InvalidComptimeType {
+        /// The expected type.
+        expected: ExpectedType,
+    },
+    /// The index is out of bounds.
+    IndexOutOfBounds {
+        /// The index that is out of bounds.
+        index: usize,
+        /// The length indexed object.
+        length: usize,
+    },
 }
 
 impl Display for IllegalIndexingReason {
@@ -346,6 +406,9 @@ impl Display for IllegalIndexingReason {
             Self::NotIdentifier => {
                 write!(f, "The expression is not an identifier.")
             }
+            Self::NotIndexable => {
+                write!(f, "The expression cannot be indexed.")
+            }
             Self::InvalidComptimeType { expected } => {
                 write!(
                     f,
@@ -361,3 +424,57 @@ impl Display for IllegalIndexingReason {
         }
     }
 }
+
+/// An error that occurs when an indexing operation is not permitted.
+#[derive(Debug, Clone, PartialEq, Eq, Getters)]
+pub struct InvalidArgument {
+    /// The span of the argument.
+    #[get = "pub"]
+    pub span: Span,
+    /// The reason why the argument is invalid.
+    #[get = "pub"]
+    pub reason: String,
+}
+
+impl Display for InvalidArgument {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", Message::new(Severity::Error, &self.reason))?;
+
+        write!(
+            f,
+            "\n{}",
+            SourceCodeDisplay::new(&self.span, Option::<u8>::None)
+        )
+    }
+}
+
+impl std::error::Error for InvalidArgument {}
+
+/// An error that occurs when an indexing operation is not permitted.
+#[derive(Debug, Clone, PartialEq, Eq, Getters)]
+pub struct NotComptime {
+    /// The expression that cannot be evaluated at compile time.
+    #[get = "pub"]
+    pub expression: Span,
+}
+
+impl Display for NotComptime {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            Message::new(
+                Severity::Error,
+                "The expression cannot be evaluated at compile time but is required to."
+            )
+        )?;
+
+        write!(
+            f,
+            "\n{}",
+            SourceCodeDisplay::new(&self.expression, Option::<u8>::None)
+        )
+    }
+}
+
+impl std::error::Error for NotComptime {}

src/transpile/expression.rs

@@ -1,15 +1,8 @@
 //! The expression transpiler.
 
-use std::{fmt::Display, string::ToString, sync::Arc};
+use std::{fmt::Display, string::ToString};
 
-use super::{util::MacroString, Scope, VariableData};
-use crate::{
-    base::{self, Handler, VoidHandler},
-    lexical::token::MacroStringLiteralPart,
-    syntax::syntax_tree::expression::{
-        Binary, BinaryOperator, Expression, PrefixOperator, Primary,
-    },
-};
+use super::util::MacroString;
 
 #[cfg(feature = "shulkerbox")]
 use enum_as_inner::EnumAsInner;
@@ -19,17 +12,25 @@ use shulkerbox::prelude::{Command, Condition, Execute};
 
 #[cfg(feature = "shulkerbox")]
 use super::{
-    error::{IllegalIndexing, IllegalIndexingReason, MismatchedTypes, UnknownIdentifier},
-    TranspileResult, Transpiler,
+    error::{
+        IllegalIndexing, IllegalIndexingReason, MismatchedTypes, NotComptime, UnknownIdentifier,
+    },
+    Scope, TranspileResult, Transpiler, VariableData,
 };
 #[cfg(feature = "shulkerbox")]
 use crate::{
-    base::source_file::SourceElement,
+    base::{self, source_file::SourceElement, Handler, VoidHandler},
+    lexical::token::MacroStringLiteralPart,
+    syntax::syntax_tree::expression::{
+        Binary, BinaryOperator, Expression, PrefixOperator, Primary,
+    },
     transpile::{
         error::{FunctionArgumentsNotAllowed, MissingValue},
         TranspileError,
     },
 };
+#[cfg(feature = "shulkerbox")]
+use std::sync::Arc;
 
 /// Compile-time evaluated value
 #[allow(missing_docs)]
@@ -85,7 +86,7 @@ impl Display for ValueType {
 }
 
 #[allow(missing_docs)]
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum ExpectedType {
     Boolean,
     Integer,
@@ -227,6 +228,7 @@ pub enum ExtendedCondition {
     Comptime(bool),
 }
 
+#[cfg(feature = "shulkerbox")]
 impl Expression {
     /// Returns whether the expression can yield a certain type.
     #[must_use]
@@ -238,12 +240,14 @@ impl Expression {
     }
 
     /// Evaluate at compile-time.
-    #[must_use]
+    ///
+    /// # Errors
+    /// - If the expression is not compile-time evaluatable.
     pub fn comptime_eval(
         &self,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
-    ) -> Option<ComptimeValue> {
+    ) -> Result<ComptimeValue, NotComptime> {
         match self {
             Self::Primary(primary) => primary.comptime_eval(scope, handler),
             Self::Binary(binary) => binary.comptime_eval(scope, handler),
@@ -251,6 +255,7 @@ impl Expression {
     }
 }
 
+#[cfg(feature = "shulkerbox")]
 impl Primary {
     /// Returns whether the primary can yield a certain type.
     #[must_use]
@@ -332,19 +337,40 @@ impl Primary {
     }
 
     /// Evaluate at compile-time.
-    #[must_use]
+    ///
+    /// # Errors
+    /// - If the expression is not compile-time evaluatable.
     pub fn comptime_eval(
         &self,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
-    ) -> Option<ComptimeValue> {
+    ) -> Result<ComptimeValue, NotComptime> {
         match self {
-            Self::Boolean(boolean) => Some(ComptimeValue::Boolean(boolean.value())),
-            Self::Integer(int) => Some(ComptimeValue::Integer(int.as_i64())),
-            Self::StringLiteral(string_literal) => Some(ComptimeValue::String(
+            Self::Boolean(boolean) => Ok(ComptimeValue::Boolean(boolean.value())),
+            Self::Integer(int) => Ok(ComptimeValue::Integer(int.as_i64())),
+            Self::StringLiteral(string_literal) => Ok(ComptimeValue::String(
                 string_literal.str_content().to_string(),
             )),
-            Self::Identifier(_) | Self::FunctionCall(_) | Self::Indexed(_) => None,
+            Self::Identifier(ident) => scope.get_variable(ident.span.str()).map_or_else(
+                || {
+                    Err(NotComptime {
+                        expression: self.span(),
+                    })
+                },
+                |var| match var.as_ref() {
+                    VariableData::ComptimeValue { value } => {
+                        value.read().unwrap().clone().ok_or_else(|| NotComptime {
+                            expression: ident.span.clone(),
+                        })
+                    }
+                    _ => Err(NotComptime {
+                        expression: self.span(),
+                    }),
+                },
+            ),
+            Self::FunctionCall(_) | Self::Indexed(_) => Err(NotComptime {
+                expression: self.span(),
+            }),
             Self::Parenthesized(parenthesized) => {
                 parenthesized.expression().comptime_eval(scope, handler)
             }
@@ -354,12 +380,14 @@ impl Primary {
                     .comptime_eval(scope, handler)
                     .and_then(|val| match (prefix.operator(), val) {
                         (PrefixOperator::LogicalNot(_), ComptimeValue::Boolean(boolean)) => {
-                            Some(ComptimeValue::Boolean(!boolean))
+                            Ok(ComptimeValue::Boolean(!boolean))
                         }
                         (PrefixOperator::Negate(_), ComptimeValue::Integer(int)) => {
-                            Some(ComptimeValue::Integer(-int))
+                            Ok(ComptimeValue::Integer(-int))
                         }
-                        _ => None,
+                        _ => Err(NotComptime {
+                            expression: prefix.span(),
+                        }),
                     })
             }
             Self::Lua(lua) => lua
@@ -367,25 +395,28 @@ impl Primary {
                 .inspect_err(|err| {
                     handler.receive(err.clone());
                 })
-                .ok()
-                .flatten(),
+                .map_err(|_| NotComptime {
+                    expression: lua.span(),
+                })
+                .and_then(|val| val),
             Self::MacroStringLiteral(macro_string_literal) => {
                 if macro_string_literal
                     .parts()
                     .iter()
                     .any(|part| matches!(part, MacroStringLiteralPart::MacroUsage { .. }))
                 {
-                    Some(ComptimeValue::MacroString(
+                    Ok(ComptimeValue::MacroString(
                         macro_string_literal.clone().into(),
                     ))
                 } else {
-                    Some(ComptimeValue::String(macro_string_literal.str_content()))
+                    Ok(ComptimeValue::String(macro_string_literal.str_content()))
                 }
             }
         }
     }
 }
 
+#[cfg(feature = "shulkerbox")]
 impl Binary {
     /// Returns whether the binary can yield a certain type.
     #[must_use]
@@ -428,12 +459,14 @@ impl Binary {
     }
 
     /// Evaluate at compile-time.
-    #[must_use]
+    ///
+    /// # Errors
+    /// - If the expression is not compile-time evaluatable.
     pub fn comptime_eval(
         &self,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
-    ) -> Option<ComptimeValue> {
+    ) -> Result<ComptimeValue, NotComptime> {
         let left = self.left_operand().comptime_eval(scope, handler)?;
         let right = self.right_operand().comptime_eval(scope, handler)?;
 
@@ -447,7 +480,7 @@ impl Binary {
                         .right_operand()
                         .can_yield_type(ValueType::Boolean, scope) =>
             {
-                Some(ComptimeValue::Boolean(true))
+                Ok(ComptimeValue::Boolean(true))
             }
             (ComptimeValue::Boolean(false), _) | (_, ComptimeValue::Boolean(false))
                 if matches!(self.operator(), BinaryOperator::LogicalAnd(..))
@@ -458,15 +491,17 @@ impl Binary {
                         .right_operand()
                         .can_yield_type(ValueType::Boolean, scope) =>
             {
-                Some(ComptimeValue::Boolean(false))
+                Ok(ComptimeValue::Boolean(false))
             }
             (ComptimeValue::Boolean(left), ComptimeValue::Boolean(right)) => {
                 match self.operator() {
-                    BinaryOperator::Equal(..) => Some(ComptimeValue::Boolean(left == right)),
-                    BinaryOperator::NotEqual(..) => Some(ComptimeValue::Boolean(left != right)),
-                    BinaryOperator::LogicalAnd(..) => Some(ComptimeValue::Boolean(left && right)),
-                    BinaryOperator::LogicalOr(..) => Some(ComptimeValue::Boolean(left || right)),
-                    _ => None,
+                    BinaryOperator::Equal(..) => Ok(ComptimeValue::Boolean(left == right)),
+                    BinaryOperator::NotEqual(..) => Ok(ComptimeValue::Boolean(left != right)),
+                    BinaryOperator::LogicalAnd(..) => Ok(ComptimeValue::Boolean(left && right)),
+                    BinaryOperator::LogicalOr(..) => Ok(ComptimeValue::Boolean(left || right)),
+                    _ => Err(NotComptime {
+                        expression: self.span(),
+                    }),
                 }
             }
             (ComptimeValue::Integer(left), ComptimeValue::Integer(right)) => {
@@ -496,14 +531,37 @@ impl Binary {
                     }
                     _ => None,
                 }
+                .ok_or_else(|| NotComptime {
+                    expression: self.span(),
+                })
             }
             (ComptimeValue::String(left), ComptimeValue::String(right)) => match self.operator() {
-                BinaryOperator::Add(..) => Some(ComptimeValue::String(left + &right)),
-                BinaryOperator::Equal(..) => Some(ComptimeValue::Boolean(left == right)),
-                BinaryOperator::NotEqual(..) => Some(ComptimeValue::Boolean(left != right)),
-                _ => None,
+                BinaryOperator::Add(..) => Ok(ComptimeValue::String(left + &right)),
+                BinaryOperator::Equal(..) => Ok(ComptimeValue::Boolean(left == right)),
+                BinaryOperator::NotEqual(..) => Ok(ComptimeValue::Boolean(left != right)),
+                _ => Err(NotComptime {
+                    expression: self.span(),
+                }),
             },
-            _ => None,
+            // TODO: also allow macro strings
+            (
+                left @ ComptimeValue::String(_),
+                right @ (ComptimeValue::Boolean(_) | ComptimeValue::Integer(_)),
+            )
+            | (
+                left @ (ComptimeValue::Boolean(_) | ComptimeValue::Integer(_)),
+                right @ ComptimeValue::String(_),
+            ) => match self.operator() {
+                BinaryOperator::Add(_) => Ok(ComptimeValue::String(
+                    left.to_string_no_macro().unwrap() + &right.to_string_no_macro().unwrap(),
+                )),
+                _ => Err(NotComptime {
+                    expression: self.span(),
+                }),
+            },
+            _ => Err(NotComptime {
+                expression: self.span(),
+            }),
         }
     }
 }
@@ -639,7 +697,7 @@ impl Transpiler {
             Primary::Lua(lua) =>
             {
                 #[expect(clippy::option_if_let_else)]
-                if let Some(value) = lua.eval_comptime(scope, handler)? {
+                if let Ok(value) = lua.eval_comptime(scope, handler)? {
                     self.store_comptime_value(&value, target, lua, handler)
                 } else {
                     let err = TranspileError::MissingValue(MissingValue {
@@ -801,7 +859,7 @@ impl Transpiler {
                 if let Some(variable) = variable.as_deref() {
                     let from = match variable {
                         VariableData::Scoreboard { objective } => {
-                            if let Some(ComptimeValue::String(target)) =
+                            if let Ok(ComptimeValue::String(target)) =
                                 indexed.index().comptime_eval(scope, handler)
                             {
                                 Ok(DataLocation::ScoreboardValue {
@@ -820,7 +878,7 @@ impl Transpiler {
                             }
                         }
                         VariableData::ScoreboardArray { objective, targets } => {
-                            if let Some(ComptimeValue::Integer(index)) =
+                            if let Ok(ComptimeValue::Integer(index)) =
                                 indexed.index().comptime_eval(scope, handler)
                             {
                                 if let Some(target) = usize::try_from(index)
@@ -858,7 +916,7 @@ impl Transpiler {
                             storage_name,
                             paths,
                         } => {
-                            if let Some(ComptimeValue::Integer(index)) =
+                            if let Ok(ComptimeValue::Integer(index)) =
                                 indexed.index().comptime_eval(scope, handler)
                             {
                                 if let Some(path) = usize::try_from(index)
@@ -915,14 +973,14 @@ impl Transpiler {
         }
     }
 
-    fn transpile_binary_expression(
+    pub(super) fn transpile_binary_expression(
         &mut self,
         binary: &Binary,
         target: &DataLocation,
         scope: &Arc<super::Scope>,
         handler: &impl Handler<base::Error>,
     ) -> TranspileResult<Vec<Command>> {
-        if let Some(value) = binary.comptime_eval(scope, handler) {
+        if let Ok(value) = binary.comptime_eval(scope, handler) {
             self.store_comptime_value(&value, target, binary, handler)
         } else {
             match binary.operator() {
@@ -1085,7 +1143,7 @@ impl Transpiler {
                             storage_name,
                             paths,
                         } => {
-                            if let Some(ComptimeValue::Integer(index)) =
+                            if let Ok(ComptimeValue::Integer(index)) =
                                 indexed.index().comptime_eval(scope, handler)
                             {
                                 if let Some(path) = usize::try_from(index)
@@ -1166,15 +1224,15 @@ impl Transpiler {
                 }
             },
             Primary::Lua(lua) => match lua.eval_comptime(scope, handler)? {
-                Some(ComptimeValue::String(value)) => Ok((
+                Ok(ComptimeValue::String(value)) => Ok((
                     Vec::new(),
                     ExtendedCondition::Runtime(Condition::Atom(value.into())),
                 )),
-                Some(ComptimeValue::MacroString(value)) => Ok((
+                Ok(ComptimeValue::MacroString(value)) => Ok((
                     Vec::new(),
                     ExtendedCondition::Runtime(Condition::Atom(value.into())),
                 )),
-                Some(ComptimeValue::Boolean(boolean)) => {
+                Ok(ComptimeValue::Boolean(boolean)) => {
                     Ok((Vec::new(), ExtendedCondition::Comptime(boolean)))
                 }
                 _ => {

src/transpile/function.rs

@@ -102,6 +102,7 @@ impl Transpiler {
                     TranspileAnnotationValue::None => Ok(identifier_span.str().to_string()),
                     TranspileAnnotationValue::Expression(expr) => expr
                         .comptime_eval(scope, handler)
+                        .ok()
                         .and_then(|val| val.to_string_no_macro())
                         .ok_or_else(|| {
                             let err = TranspileError::IllegalAnnotationContent(
@@ -293,13 +294,10 @@ impl Transpiler {
                     let value = match expression {
                         Expression::Primary(Primary::Lua(lua)) => {
                             lua.eval_comptime(scope, handler).and_then(|val| match val {
-                                Some(ComptimeValue::MacroString(s)) => Ok(Parameter::Static(s)),
-                                Some(val) => Ok(Parameter::Static(val.to_macro_string())),
-                                None => {
-                                    let err = TranspileError::MismatchedTypes(MismatchedTypes {
-                                        expression: expression.span(),
-                                        expected_type: ExpectedType::String,
-                                    });
+                                Ok(ComptimeValue::MacroString(s)) => Ok(Parameter::Static(s)),
+                                Ok(val) => Ok(Parameter::Static(val.to_macro_string())),
+                                Err(err) => {
+                                    let err = TranspileError::NotComptime(err);
                                     handler.receive(err.clone());
                                     Err(err)
                                 }
@@ -361,7 +359,18 @@ impl Transpiler {
                                         path: std::mem::take(&mut temp_path[0]),
                                     })
                                 }
-                                _ => todo!("other variable types"),
+                                _ => {
+                                    let err = TranspileError::MismatchedTypes(MismatchedTypes {
+                                        expression: expression.span(),
+                                        expected_type: ExpectedType::AnyOf(vec![
+                                            ExpectedType::Integer,
+                                            ExpectedType::Boolean,
+                                            ExpectedType::String,
+                                        ]),
+                                    });
+                                    handler.receive(err.clone());
+                                    Err(err)
+                                }
                             }
                         }
                         Expression::Primary(

src/transpile/internal_functions.rs

@@ -5,6 +5,7 @@ use std::{
     sync::Arc,
 };
 
+use cfg_if::cfg_if;
 use shulkerbox::prelude::{Command, Execute};
 
 use serde_json::{json, Value as JsonValue};
@@ -15,8 +16,8 @@ use crate::{
     semantic::error::{InvalidFunctionArguments, UnexpectedExpression},
     syntax::syntax_tree::expression::{Expression, FunctionCall, Primary},
     transpile::{
-        error::{IllegalIndexing, IllegalIndexingReason, LuaRuntimeError, UnknownIdentifier},
-        expression::{ComptimeValue, DataLocation, StorageType},
+        error::{IllegalIndexing, IllegalIndexingReason, UnknownIdentifier},
+        expression::{ComptimeValue, DataLocation, ExpectedType, StorageType},
         util::MacroString,
         TranspileError,
     },
@@ -182,17 +183,17 @@ fn print_function(
 
     let args = get_args_assert_in_range(call, 1..=2)?;
     let first = args.first().expect("checked range");
-    let (target, message_expression) = args.get(1).map_or_else(
-        || ("@a".into(), first),
-        |second| {
-            (
-                first
-                    .comptime_eval(scope, &VoidHandler)
-                    .map_or_else(|| "@a".into(), |val| val.to_macro_string()),
-                second,
-            )
-        },
-    );
+    let (target, message_expression) = if let Some(second) = args.get(1) {
+        (
+            first
+                .comptime_eval(scope, &VoidHandler)
+                .map(|val| val.to_macro_string())
+                .map_err(TranspileError::NotComptime)?,
+            second,
+        )
+    } else {
+        ("@a".into(), first)
+    };
 
     let mut contains_macro = matches!(target, MacroString::MacroString(_));
 
@@ -210,17 +211,24 @@ fn print_function(
                 Vec::new(),
                 vec![JsonValue::String(string.str_content().to_string())],
             )),
+            #[cfg_attr(not(feature = "lua"), expect(unused_variables))]
             Primary::Lua(lua) => {
-                let (ret, _lua) = lua.eval(scope, &VoidHandler)?;
-                Ok((
-                    Vec::new(),
-                    vec![JsonValue::String(ret.to_string().map_err(|err| {
-                        TranspileError::LuaRuntimeError(LuaRuntimeError::from_lua_err(
-                            &err,
-                            lua.span(),
+                cfg_if! {
+                    if #[cfg(feature = "lua")] {
+                        let (ret, _lua) = lua.eval(scope, &VoidHandler)?;
+                        Ok((
+                            Vec::new(),
+                            vec![JsonValue::String(ret.to_string().map_err(|err| {
+                                TranspileError::LuaRuntimeError(super::error::LuaRuntimeError::from_lua_err(
+                                    &err,
+                                    lua.span(),
+                                ))
+                            })?)],
                         ))
-                    })?)],
-                ))
+                    } else {
+                        Err(TranspileError::LuaDisabled)
+                    }
+                }
             }
             Primary::Identifier(ident) => {
                 let (cur_contains_macro, cmd, part) =
@@ -232,7 +240,7 @@ fn print_function(
                 Primary::Identifier(ident) => {
                     match scope.get_variable(ident.span.str()).as_deref() {
                         Some(VariableData::Scoreboard { objective }) => {
-                            if let Some(ComptimeValue::String(index)) =
+                            if let Ok(ComptimeValue::String(index)) =
                                 indexed.index().comptime_eval(scope, &VoidHandler)
                             {
                                 let (cmd, value) = get_data_location(
@@ -244,11 +252,17 @@ fn print_function(
                                 );
                                 Ok((cmd.into_iter().collect(), vec![value]))
                             } else {
-                                todo!("allow macro string, but throw error when index is not constant string")
+                                // TODO: allow macro string, but throw error when index is not constant string
+                                Err(TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::String,
+                                    },
+                                    expression: indexed.index().span(),
+                                }))
                             }
                         }
                         Some(VariableData::ScoreboardArray { objective, targets }) => {
-                            if let Some(ComptimeValue::Integer(index)) =
+                            if let Ok(ComptimeValue::Integer(index)) =
                                 indexed.index().comptime_eval(scope, &VoidHandler)
                             {
                                 #[expect(clippy::option_if_let_else)]
@@ -274,14 +288,19 @@ fn print_function(
                                     }))
                                 }
                             } else {
-                                todo!("throw error when index is not constant integer")
+                                Err(TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::Integer,
+                                    },
+                                    expression: indexed.index().span(),
+                                }))
                             }
                         }
                         Some(VariableData::BooleanStorageArray {
                             storage_name,
                             paths,
                         }) => {
-                            if let Some(ComptimeValue::Integer(index)) =
+                            if let Ok(ComptimeValue::Integer(index)) =
                                 indexed.index().comptime_eval(scope, &VoidHandler)
                             {
                                 #[expect(clippy::option_if_let_else)]
@@ -308,10 +327,18 @@ fn print_function(
                                     }))
                                 }
                             } else {
-                                todo!("throw error when index is not constant integer")
+                                Err(TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::Integer,
+                                    },
+                                    expression: indexed.index().span(),
+                                }))
                             }
                         }
-                        _ => todo!("catch illegal indexing"),
+                        _ => Err(TranspileError::IllegalIndexing(IllegalIndexing {
+                            reason: IllegalIndexingReason::NotIndexable,
+                            expression: indexed.object().span(),
+                        })),
                     }
                 }
                 _ => Err(TranspileError::IllegalIndexing(IllegalIndexing {
@@ -339,9 +366,43 @@ fn print_function(
                 Ok((cmds, parts))
             }
 
-            _ => todo!("print_function Primary"),
+            primary => {
+                let (storage_name, mut storage_paths) = transpiler.get_temp_storage_locations(1);
+                let location = DataLocation::Storage {
+                    storage_name,
+                    path: std::mem::take(&mut storage_paths[0]),
+                    r#type: StorageType::Int,
+                };
+                let cmds = transpiler.transpile_primary_expression(
+                    primary,
+                    &location,
+                    scope,
+                    &VoidHandler,
+                )?;
+                let (cmd, part) = get_data_location(&location, transpiler);
+
+                Ok((
+                    cmds.into_iter().chain(cmd.into_iter()).collect(),
+                    vec![part],
+                ))
+            }
         },
-        Expression::Binary(_) => todo!("print_function Binary"),
+        Expression::Binary(binary) => {
+            let (storage_name, mut storage_paths) = transpiler.get_temp_storage_locations(1);
+            let location = DataLocation::Storage {
+                storage_name,
+                path: std::mem::take(&mut storage_paths[0]),
+                r#type: StorageType::Int,
+            };
+            let cmds =
+                transpiler.transpile_binary_expression(binary, &location, scope, &VoidHandler)?;
+            let (cmd, part) = get_data_location(&location, transpiler);
+
+            Ok((
+                cmds.into_iter().chain(cmd.into_iter()).collect(),
+                vec![part],
+            ))
+        }
     }?;
 
     // TODO: prepend prefix with datapack name to parts and remove following

src/transpile/lua.rs

@@ -1,6 +1,6 @@
 //! Executes the Lua code and returns the resulting command.
 
-#[cfg(feature = "lua")]
+#[cfg(all(feature = "lua", feature = "shulkerbox"))]
 mod enabled {
     use std::sync::Arc;
 
@@ -12,8 +12,8 @@ mod enabled {
         syntax::syntax_tree::expression::LuaCode,
         transpile::{
             error::{
-                LuaRuntimeError, MismatchedTypes, TranspileError, TranspileResult,
-                UnknownIdentifier,
+                InvalidArgument, LuaRuntimeError, MismatchedTypes, NotComptime, TranspileError,
+                TranspileResult, UnknownIdentifier,
             },
             expression::{ComptimeValue, ExpectedType},
             Scope, VariableData,
@@ -86,11 +86,15 @@ mod enabled {
             &self,
             scope: &Arc<Scope>,
             handler: &impl Handler<base::Error>,
-        ) -> TranspileResult<Option<ComptimeValue>> {
+        ) -> TranspileResult<Result<ComptimeValue, NotComptime>> {
             // required to keep the lua instance alive
             let (lua_result, _lua) = self.eval(scope, handler)?;
 
-            self.handle_lua_result(lua_result, handler)
+            self.handle_lua_result(lua_result, handler).map(|res| {
+                res.ok_or_else(|| NotComptime {
+                    expression: self.span(),
+                })
+            })
         }
 
         fn add_globals(&self, lua: &Lua, scope: &Arc<Scope>) -> TranspileResult<()> {
@@ -262,8 +266,28 @@ mod enabled {
                         .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
                     Value::Table(table)
                 }
+                Some(VariableData::ComptimeValue { value }) => {
+                    let value = value.read().unwrap();
+                    match &*value {
+                        Some(ComptimeValue::Boolean(b)) => Value::Boolean(*b),
+                        Some(ComptimeValue::Integer(i)) => Value::Integer(*i),
+                        Some(ComptimeValue::String(s)) => Value::String(
+                            lua.create_string(s)
+                                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                        ),
+                        Some(ComptimeValue::MacroString(s)) => Value::String(
+                            lua.create_string(s.to_string())
+                                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                        ),
+                        None => Value::Nil,
+                    }
+                }
                 Some(VariableData::Function { .. } | VariableData::InternalFunction { .. }) => {
-                    todo!("(internal) functions are not supported yet");
+                    // TODO: add support for functions
+                    return Err(TranspileError::InvalidArgument(InvalidArgument {
+                        reason: "functions cannot be passed to Lua".to_string(),
+                        span: identifier.span(),
+                    }));
                 }
                 None => {
                     return Err(TranspileError::UnknownIdentifier(UnknownIdentifier {
@@ -374,7 +398,7 @@ mod enabled {
     }
 }
 
-#[cfg(not(feature = "lua"))]
+#[cfg(all(not(feature = "lua"), feature = "shulkerbox"))]
 mod disabled {
     use std::sync::Arc;
 
@@ -397,7 +421,7 @@ mod disabled {
             &self,
             scope: &Arc<Scope>,
             handler: &impl Handler<base::Error>,
-        ) -> TranspileResult<()> {
+        ) -> TranspileResult<((), ())> {
             let _ = scope;
             handler.receive(TranspileError::LuaDisabled);
             tracing::error!("Lua code evaluation is disabled");

src/transpile/mod.rs

@@ -16,7 +16,7 @@ use crate::{
 #[doc(hidden)]
 #[cfg(feature = "shulkerbox")]
 pub mod conversions;
-mod error;
+pub mod error;
 
 pub mod expression;
 
@@ -38,9 +38,12 @@ pub mod internal_functions;
 #[doc(hidden)]
 #[cfg(feature = "shulkerbox")]
 pub mod function;
+#[doc(inline)]
+#[cfg(feature = "shulkerbox")]
 pub use function::TranspiledFunctionArguments;
 
 mod variables;
+#[cfg(feature = "shulkerbox")]
 pub use variables::{Scope, VariableData};
 
 pub mod util;
@@ -58,7 +61,7 @@ pub struct FunctionData {
 
 /// Possible values for an annotation.
 #[expect(clippy::module_name_repetitions)]
-#[derive(Debug, Clone, PartialEq, Eq, EnumIs)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash, EnumIs)]
 pub enum TranspileAnnotationValue {
     /// No value.
     None,

src/transpile/transpiler.rs

@@ -25,7 +25,7 @@ use crate::{
 };
 
 use super::{
-    error::{MismatchedTypes, TranspileError, TranspileResult},
+    error::{MismatchedTypes, MissingValue, TranspileError, TranspileResult, UnknownIdentifier},
     expression::{ComptimeValue, ExpectedType, ExtendedCondition},
     variables::{Scope, TranspileAssignmentTarget, VariableData},
     FunctionData, TranspileAnnotationValue, TranspiledFunctionArguments,
@@ -342,11 +342,46 @@ impl Transpiler {
             Expression::Primary(Primary::FunctionCall(func)) => {
                 self.transpile_function_call(func, scope, handler)
             }
+            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(
+                            || {
+                                let error = TranspileError::MissingValue(MissingValue {
+                                    expression: ident.span.clone(),
+                                });
+                                handler.receive(error.clone());
+                                Err(error)
+                            },
+                            |val| {
+                                let cmd = val.to_string_no_macro().map_or_else(
+                                    || Command::UsesMacro(val.to_macro_string().into()),
+                                    Command::Raw,
+                                );
+                                Ok(vec![cmd])
+                            },
+                        )
+                    }
+                    Some(_) => {
+                        let error = TranspileError::UnexpectedExpression(UnexpectedExpression(
+                            expression.clone(),
+                        ));
+                        handler.receive(error.clone());
+                        Err(error)
+                    }
+                    None => {
+                        let error = TranspileError::UnknownIdentifier(UnknownIdentifier {
+                            identifier: ident.span.clone(),
+                        });
+                        handler.receive(error.clone());
+                        Err(error)
+                    }
+                }
+            }
             expression @ Expression::Primary(
                 Primary::Integer(_)
                 | Primary::Boolean(_)
                 | Primary::Prefix(_)
-                | Primary::Identifier(_)
                 | Primary::Indexed(_),
             ) => {
                 let error =
@@ -361,9 +396,9 @@ impl Transpiler {
                 Ok(vec![Command::UsesMacro(string.into())])
             }
             Expression::Primary(Primary::Lua(code)) => match code.eval_comptime(scope, handler)? {
-                Some(ComptimeValue::String(cmd)) => Ok(vec![Command::Raw(cmd)]),
-                Some(ComptimeValue::MacroString(cmd)) => Ok(vec![Command::UsesMacro(cmd.into())]),
-                Some(ComptimeValue::Boolean(_) | ComptimeValue::Integer(_)) => {
+                Ok(ComptimeValue::String(cmd)) => Ok(vec![Command::Raw(cmd)]),
+                Ok(ComptimeValue::MacroString(cmd)) => Ok(vec![Command::UsesMacro(cmd.into())]),
+                Ok(ComptimeValue::Boolean(_) | ComptimeValue::Integer(_)) => {
                     let err = TranspileError::MismatchedTypes(MismatchedTypes {
                         expected_type: ExpectedType::String,
                         expression: code.span(),
@@ -371,7 +406,13 @@ impl Transpiler {
                     handler.receive(err.clone());
                     Err(err)
                 }
-                None => Ok(Vec::new()),
+                Err(_) => {
+                    let err = TranspileError::MissingValue(MissingValue {
+                        expression: code.span(),
+                    });
+                    handler.receive(err.clone());
+                    Err(err)
+                }
             },
 
             Expression::Primary(Primary::Parenthesized(parenthesized)) => self
@@ -382,8 +423,8 @@ impl Transpiler {
                     handler,
                 ),
             Expression::Binary(bin) => match bin.comptime_eval(scope, handler) {
-                Some(ComptimeValue::String(cmd)) => Ok(vec![Command::Raw(cmd)]),
-                Some(ComptimeValue::MacroString(cmd)) => Ok(vec![Command::UsesMacro(cmd.into())]),
+                Ok(ComptimeValue::String(cmd)) => Ok(vec![Command::Raw(cmd)]),
+                Ok(ComptimeValue::MacroString(cmd)) => Ok(vec![Command::UsesMacro(cmd.into())]),
                 _ => {
                     let err = TranspileError::MismatchedTypes(MismatchedTypes {
                         expression: bin.span(),
@@ -621,7 +662,7 @@ impl Transpiler {
             }
         });
 
-        if let Some(ComptimeValue::Boolean(value)) = cond_expression.comptime_eval(scope, handler) {
+        if let Ok(ComptimeValue::Boolean(value)) = cond_expression.comptime_eval(scope, handler) {
             if value {
                 Ok(Some((Vec::new(), then)))
             } else {

src/transpile/variables.rs

@@ -30,17 +30,17 @@ use crate::{
 use super::{
     error::{
         AssignmentError, IllegalAnnotationContent, IllegalIndexing, IllegalIndexingReason,
-        MismatchedTypes,
+        MismatchedTypes, NotComptime,
     },
     expression::{ComptimeValue, DataLocation, ExpectedType, StorageType},
-    internal_functions::InternalFunction,
     FunctionData, TranspileAnnotationValue, TranspileError, TranspileResult,
 };
 
 #[cfg(feature = "shulkerbox")]
-use super::Transpiler;
+use super::{internal_functions::InternalFunction, Transpiler};
 
 /// Stores the data required to access a variable.
+#[cfg(feature = "shulkerbox")]
 #[derive(Debug, Clone, EnumAsInner)]
 pub enum VariableData {
     /// A function.
@@ -100,6 +100,11 @@ pub enum VariableData {
         /// The implementation
         implementation: InternalFunction,
     },
+    /// Compiler internal variable.
+    ComptimeValue {
+        /// The value.
+        value: Arc<RwLock<Option<ComptimeValue>>>,
+    },
 }
 
 #[derive(Debug, Clone, Copy, EnumAsInner)]
@@ -122,6 +127,7 @@ impl<'a> From<&'a AssignmentDestination> for TranspileAssignmentTarget<'a> {
 }
 
 /// A scope that stores variables.
+#[cfg(feature = "shulkerbox")]
 #[derive(Default)]
 pub struct Scope<'a> {
     /// Parent scope where variables are inherited from.
@@ -132,6 +138,7 @@ pub struct Scope<'a> {
     shadowed: RwLock<HashMap<String, usize>>,
 }
 
+#[cfg(feature = "shulkerbox")]
 impl<'a> Scope<'a> {
     /// Creates a new scope.
     #[must_use]
@@ -226,6 +233,7 @@ impl<'a> Scope<'a> {
     }
 }
 
+#[cfg(feature = "shulkerbox")]
 impl Debug for Scope<'_> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         struct VariableWrapper<'a>(&'a RwLock<HashMap<String, Arc<VariableData>>>);
@@ -279,6 +287,31 @@ impl Transpiler {
                 scope,
                 handler,
             ),
+            VariableDeclaration::ComptimeValue(declaration) => {
+                let value = if let Some(assignment) = declaration.assignment() {
+                    Some(
+                        assignment
+                            .expression()
+                            .comptime_eval(scope, handler)
+                            .map_err(|err| {
+                                let err = TranspileError::NotComptime(err);
+                                handler.receive(err.clone());
+                                err
+                            })?,
+                    )
+                } else {
+                    None
+                };
+
+                scope.set_variable(
+                    declaration.identifier().span.str(),
+                    VariableData::ComptimeValue {
+                        value: Arc::new(RwLock::new(value)),
+                    },
+                );
+
+                Ok(Vec::new())
+            }
         }
     }
 
@@ -463,7 +496,7 @@ impl Transpiler {
         let (identifier, indexing_value) = match destination {
             TranspileAssignmentTarget::Identifier(ident) => (ident, None),
             TranspileAssignmentTarget::Indexed(ident, expression) => {
-                (ident, expression.comptime_eval(scope, handler))
+                (ident, expression.comptime_eval(scope, handler).ok())
             }
         };
         if let Some(target) = scope.get_variable(identifier.span.str()) {
@@ -489,7 +522,15 @@ impl Transpiler {
                         target: s,
                     }),
                     Some(ComptimeValue::MacroString(s)) => {
-                        todo!("indexing scoreboard with macro string: {s:?}")
+                        // TODO: allow indexing with macro string
+                        let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                            reason: IllegalIndexingReason::InvalidComptimeType {
+                                expected: ExpectedType::String,
+                            },
+                            expression: expression.span(),
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
                     }
                     Some(_) => {
                         let err = TranspileError::IllegalIndexing(IllegalIndexing {
@@ -621,7 +662,15 @@ impl Transpiler {
                         entity: s,
                     }),
                     Some(ComptimeValue::MacroString(s)) => {
-                        todo!("indexing tag with macro string: {s:?}")
+                        // TODO: allow indexing tag with macro string
+                        let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                            expression: expression.span(),
+                            reason: IllegalIndexingReason::InvalidComptimeType {
+                                expected: ExpectedType::String,
+                            },
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
                     }
                     Some(_) => {
                         let err = TranspileError::IllegalIndexing(IllegalIndexing {
@@ -643,6 +692,16 @@ impl Transpiler {
                         return Err(err);
                     }
                 },
+                VariableData::ComptimeValue { value } => {
+                    let comptime_value =
+                        expression.comptime_eval(scope, handler).map_err(|err| {
+                            let err = TranspileError::NotComptime(err);
+                            handler.receive(err.clone());
+                            err
+                        })?;
+                    *value.write().unwrap() = Some(comptime_value);
+                    return Ok(Vec::new());
+                }
                 VariableData::Function { .. }
                 | VariableData::MacroParameter { .. }
                 | VariableData::InternalFunction { .. } => {
@@ -704,6 +763,7 @@ impl Transpiler {
                 TranspileAnnotationValue::Expression(expr) => {
                     if let Some(name_eval) = expr
                         .comptime_eval(scope, handler)
+                        .ok()
                         .and_then(|val| val.to_string_no_macro())
                     {
                         // TODO: change invalid criteria if boolean
@@ -802,9 +862,11 @@ impl Transpiler {
                         if let (Some(name_eval), Some(target_eval)) = (
                             objective
                                 .comptime_eval(scope, handler)
+                                .ok()
                                 .and_then(|val| val.to_string_no_macro()),
                             target
                                 .comptime_eval(scope, handler)
+                                .ok()
                                 .and_then(|val| val.to_string_no_macro()),
                         ) {
                             // TODO: change invalid criteria if boolean
@@ -931,7 +993,15 @@ impl Transpiler {
                     Ok((name, targets))
                 }
                 TranspileAnnotationValue::Map(map) => {
-                    todo!("allow map deobfuscate annotation for array variables")
+                    // TODO: implement when map deobfuscate annotation is implemented
+                    let error =
+                        TranspileError::IllegalAnnotationContent(IllegalAnnotationContent {
+                            annotation: deobfuscate_annotation.span(),
+                            message: "Deobfuscate annotation value must be a string or none."
+                                .to_string(),
+                        });
+                    handler.receive(error.clone());
+                    Err(error)
                 }
                 TranspileAnnotationValue::Expression(_) => {
                     let error =

src/util.rs

@@ -107,7 +107,7 @@ pub fn identifier_to_scoreboard_target(ident: &str) -> std::borrow::Cow<str> {
         let new_ident = ident
             .chars()
             .map(|c| {
-                if *c != '_' && !c.is_ascii_alphanumeric() {
+                if c != '_' && !c.is_ascii_alphanumeric() {
                     '_'
                 } else {
                     c