first version of print internal function for easier displaying variable values

Cargo.toml

@@ -18,8 +18,8 @@ license = "MIT OR Apache-2.0"
 default = ["fs_access", "lua", "shulkerbox", "zip"]
 fs_access = ["shulkerbox?/fs_access"]
 lua = ["dep:mlua"]
-serde = ["dep:serde", "dep:flexbuffers", "shulkerbox?/serde"]
-shulkerbox = ["dep:shulkerbox", "dep:chksum-md5"]
+serde = ["dep:serde", "dep:serde_json", "shulkerbox?/serde"]
+shulkerbox = ["dep:shulkerbox", "dep:chksum-md5", "dep:serde_json"]
 zip = ["shulkerbox?/zip"]
 
 [dependencies]
@@ -28,12 +28,12 @@ chksum-md5 = { version = "0.1.0", optional = true }
 colored = "3.0.0"
 derive_more = { version = "2.0.1", default-features = false, features = ["deref", "deref_mut", "from"] }
 enum-as-inner = "0.6.0"
-flexbuffers = { version = "25.2.10", optional = true }
 getset = "0.1.2"
 itertools = "0.14.0"
 mlua = { version = "0.10.2", features = ["lua54", "vendored"], optional = true }
 pathdiff = "0.2.3"
 serde = { version = "1.0.217", features = ["derive"], optional = true }
+serde_json = { version = "1.0.138", optional = true }
 # shulkerbox = { version = "0.1.0", default-features = false, optional = true }
 shulkerbox = { git = "https://github.com/moritz-hoelting/shulkerbox", rev = "e9f2b9b91d72322ec2e063ce7b83415071306468", default-features = false, optional = true }
 strsim = "0.11.1"

src/semantic/error.rs

@@ -33,6 +33,7 @@ pub enum Error {
     IncompatibleFunctionAnnotation(#[from] IncompatibleFunctionAnnotation),
 }
 
+// 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 {
@@ -43,6 +44,7 @@ pub struct MissingFunctionDeclaration {
 }
 
 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

src/semantic/mod.rs

@@ -4,14 +4,11 @@
 
 use std::collections::HashSet;
 
-use error::{
-    IncompatibleFunctionAnnotation, InvalidNamespaceName, MissingFunctionDeclaration,
-    UnresolvedMacroUsage,
-};
+use error::{IncompatibleFunctionAnnotation, InvalidNamespaceName};
 
 use crate::{
     base::{self, source_file::SourceElement as _, Handler},
-    lexical::token::{MacroStringLiteral, MacroStringLiteralPart},
+    lexical::token::MacroStringLiteral,
     syntax::syntax_tree::{
         declaration::{Declaration, Function, ImportItems},
         expression::{Expression, FunctionCall, Parenthesized, Primary},
@@ -387,28 +384,29 @@ impl MacroStringLiteral {
     /// Analyzes the semantics of the macro string literal.
     pub fn analyze_semantics(
         &self,
-        macro_names: &HashSet<String>,
-        handler: &impl Handler<base::Error>,
+        _macro_names: &HashSet<String>,
+        _handler: &impl Handler<base::Error>,
     ) -> Result<(), error::Error> {
-        let mut errors = Vec::new();
-        for part in self.parts() {
-            if let MacroStringLiteralPart::MacroUsage { identifier, .. } = part {
-                if !macro_names.contains(identifier.span.str()) {
-                    let err = error::Error::UnresolvedMacroUsage(UnresolvedMacroUsage {
-                        span: identifier.span(),
-                    });
-                    handler.receive(err.clone());
-                    errors.push(err);
-                }
-            }
-        }
+        // let mut errors = Vec::new();
+        // TODO: allow macro string literals to also contain other variables
+        // for part in self.parts() {
+        //     if let MacroStringLiteralPart::MacroUsage { identifier, .. } = part {
+        //         if !macro_names.contains(identifier.span.str()) {
+        //             let err = error::Error::UnresolvedMacroUsage(UnresolvedMacroUsage {
+        //                 span: identifier.span(),
+        //             });
+        //             handler.receive(err.clone());
+        //             errors.push(err);
+        //         }
+        //     }
+        // }
 
-        #[expect(clippy::option_if_let_else)]
-        if let Some(err) = errors.first() {
-            Err(err.clone())
-        } else {
-            Ok(())
-        }
+        // #[expect(clippy::option_if_let_else)]
+        // if let Some(err) = errors.first() {
+        //     Err(err.clone())
+        // } else {
+        Ok(())
+        // }
     }
 }
 
@@ -462,13 +460,14 @@ impl FunctionCall {
     ) -> Result<(), error::Error> {
         let mut errors = Vec::new();
 
-        if !function_names.contains(self.identifier().span.str()) {
-            let err = error::Error::MissingFunctionDeclaration(
-                MissingFunctionDeclaration::from_context(self.identifier().span(), function_names),
-            );
-            handler.receive(err.clone());
-            errors.push(err);
-        }
+        // TODO: also check for internal functions
+        // if !function_names.contains(self.identifier().span.str()) {
+        //     let err = error::Error::MissingFunctionDeclaration(
+        //         MissingFunctionDeclaration::from_context(self.identifier().span(), function_names),
+        //     );
+        //     handler.receive(err.clone());
+        //     errors.push(err);
+        // }
 
         for expression in self
             .arguments()

src/serde.rs

@@ -42,7 +42,7 @@ where
         // hold guard so no other can serialize at the same time in same thread
         let s = DEDUPLICATE_SOURCE_FILES.with(|d| {
             let guard = d.read().unwrap();
-            let mut serialized_data = flexbuffers::FlexbufferSerializer::new();
+            let mut serialized_data = serde_json::Serializer::new(Vec::new());
             self.0
                 .serialize(&mut serialized_data)
                 .map_err(|_| serde::ser::Error::custom("could not buffer serialization"))?;

src/syntax/syntax_tree/expression.rs

@@ -545,6 +545,20 @@ impl<'a> Parser<'a> {
                             arguments: token_tree.list,
                         }))
                     }
+                    Reading::IntoDelimited(punc) if punc.punctuation == '[' => {
+                        let token_tree = self.step_into(
+                            Delimiter::Bracket,
+                            |p| p.parse_expression(handler),
+                            handler,
+                        )?;
+
+                        Ok(Primary::Indexed(Indexed {
+                            object: Box::new(Primary::Identifier(identifier)),
+                            left_bracket: token_tree.open,
+                            index: Box::new(token_tree.tree?),
+                            right_bracket: token_tree.close,
+                        }))
+                    }
                     _ => {
                         // regular identifier
                         Ok(Primary::Identifier(identifier))

src/syntax/syntax_tree/statement.rs

@@ -572,7 +572,7 @@ pub struct ScoreVariableDeclaration {
     close_bracket: Punctuation,
     /// The optional assignment of the variable.
     #[get = "pub"]
-    target_assignment: Option<(AnyStringLiteral, VariableDeclarationAssignment)>,
+    assignment: Option<VariableDeclarationAssignment>,
     /// The annotations of the variable declaration.
     #[get = "pub"]
     annotations: VecDeque<Annotation>,
@@ -582,17 +582,18 @@ impl SourceElement for ScoreVariableDeclaration {
     fn span(&self) -> Span {
         self.int_keyword
             .span()
-            .join(&self.target_assignment.as_ref().map_or_else(
-                || self.close_bracket.span(),
-                |(_, assignment)| assignment.span(),
-            ))
+            .join(
+                &self
+                    .assignment
+                    .as_ref()
+                    .map_or_else(|| self.close_bracket.span(), SourceElement::span),
+            )
             .expect("The span of the score variable declaration is invalid.")
     }
 }
 
 impl ScoreVariableDeclaration {
     /// Dissolves the [`ScoreVariableDeclaration`] into its components.
-    #[expect(clippy::type_complexity)]
     #[must_use]
     pub fn dissolve(
         self,
@@ -602,7 +603,7 @@ impl ScoreVariableDeclaration {
         Identifier,
         Punctuation,
         Punctuation,
-        Option<(AnyStringLiteral, VariableDeclarationAssignment)>,
+        Option<VariableDeclarationAssignment>,
     ) {
         (
             self.int_keyword,
@@ -610,7 +611,7 @@ impl ScoreVariableDeclaration {
             self.identifier,
             self.open_bracket,
             self.close_bracket,
-            self.target_assignment,
+            self.assignment,
         )
     }
 }
@@ -939,9 +940,9 @@ impl<'a> Parser<'a> {
         &mut self,
         handler: &impl Handler<base::Error>,
     ) -> ParseResult<VariableDeclaration> {
+        #[derive(Debug, Clone)]
         enum IndexingType {
             IntegerSize(Integer),
-            AnyString(AnyStringLiteral),
             None,
         }
 
@@ -992,27 +993,13 @@ impl<'a> Parser<'a> {
                                 IndexingType::IntegerSize(int)
                             }
 
-                            Reading::Atomic(Token::StringLiteral(s)) => {
-                                let selector = AnyStringLiteral::from(s);
-                                p.forward();
-                                IndexingType::AnyString(selector)
-                            }
-                            Reading::Atomic(Token::MacroStringLiteral(s)) => {
-                                let selector = AnyStringLiteral::from(s);
-                                p.forward();
-                                IndexingType::AnyString(selector)
-                            }
-
                             Reading::DelimitedEnd(punc) if punc.punctuation == ']' => {
                                 IndexingType::None
                             }
 
                             unexpected => {
                                 let err = Error::UnexpectedSyntax(UnexpectedSyntax {
-                                    expected: SyntaxKind::Either(&[
-                                        SyntaxKind::Integer,
-                                        SyntaxKind::AnyStringLiteral,
-                                    ]),
+                                    expected: SyntaxKind::Integer,
                                     found: unexpected.into_token(),
                                 });
                                 handler.receive(err.clone());
@@ -1034,10 +1021,10 @@ impl<'a> Parser<'a> {
                         let assignment = self
                             .try_parse(|p| {
                                 // read equals sign
-                                let equals = p.parse_punctuation('=', true, handler)?;
+                                let equals = p.parse_punctuation('=', true, &VoidHandler)?;
 
                                 // read expression
-                                let expression = p.parse_expression(handler)?;
+                                let expression = p.parse_expression(&VoidHandler)?;
 
                                 Ok(VariableDeclarationAssignment { equals, expression })
                             })
@@ -1053,37 +1040,6 @@ impl<'a> Parser<'a> {
                             annotations: VecDeque::new(),
                         }))
                     }
-                    IndexingType::AnyString(selector) => {
-                        let equals = self.parse_punctuation('=', true, handler)?;
-                        let expression = self.parse_expression(handler)?;
-
-                        let assignment = VariableDeclarationAssignment { equals, expression };
-
-                        match variable_type.keyword {
-                            KeywordKind::Int => {
-                                Ok(VariableDeclaration::Score(ScoreVariableDeclaration {
-                                    int_keyword: variable_type,
-                                    criteria: criteria_selection,
-                                    identifier,
-                                    open_bracket,
-                                    close_bracket,
-                                    target_assignment: Some((selector, assignment)),
-                                    annotations: VecDeque::new(),
-                                }))
-                            }
-                            KeywordKind::Bool => {
-                                Ok(VariableDeclaration::Tag(TagVariableDeclaration {
-                                    bool_keyword: variable_type,
-                                    identifier,
-                                    open_bracket,
-                                    close_bracket,
-                                    target_assignment: Some((selector, assignment)),
-                                    annotations: VecDeque::new(),
-                                }))
-                            }
-                            _ => unreachable!(),
-                        }
-                    }
                     IndexingType::None => match variable_type.keyword {
                         KeywordKind::Int => {
                             Ok(VariableDeclaration::Score(ScoreVariableDeclaration {
@@ -1092,7 +1048,7 @@ impl<'a> Parser<'a> {
                                 identifier,
                                 open_bracket,
                                 close_bracket,
-                                target_assignment: None,
+                                assignment: None,
                                 annotations: VecDeque::new(),
                             }))
                         }

src/transpile/error.rs

@@ -42,6 +42,8 @@ pub enum TranspileError {
     UnknownIdentifier(#[from] UnknownIdentifier),
     #[error(transparent)]
     MissingValue(#[from] MissingValue),
+    #[error(transparent)]
+    IllegalIndexing(#[from] IllegalIndexing),
 }
 
 /// The result of a transpilation operation.
@@ -309,3 +311,54 @@ 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)]
+pub struct IllegalIndexing {
+    pub reason: IllegalIndexingReason,
+    pub expression: Span,
+}
+
+impl Display for IllegalIndexing {
+    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.expression, Option::<u8>::None)
+        )
+    }
+}
+
+impl std::error::Error for IllegalIndexing {}
+
+/// The reason why an indexing operation is not permitted.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum IllegalIndexingReason {
+    NotIdentifier,
+    InvalidComptimeType { expected: ExpectedType },
+    IndexOutOfBounds { index: usize, length: usize },
+}
+
+impl Display for IllegalIndexingReason {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::NotIdentifier => {
+                write!(f, "The expression is not an identifier.")
+            }
+            Self::InvalidComptimeType { expected } => {
+                write!(
+                    f,
+                    "The expression can only be indexed with type {expected} that can be evaluated at compile time."
+                )
+            }
+            Self::IndexOutOfBounds { index, length } => {
+                write!(
+                    f,
+                    "The index {index} is out of bounds for the expression with length {length}."
+                )
+            }
+        }
+    }
+}

src/transpile/expression.rs

@@ -19,7 +19,7 @@ use shulkerbox::prelude::{Command, Condition, Execute};
 
 #[cfg(feature = "shulkerbox")]
 use super::{
-    error::{MismatchedTypes, UnknownIdentifier},
+    error::{IllegalIndexing, IllegalIndexingReason, MismatchedTypes, UnknownIdentifier},
     TranspileResult, Transpiler,
 };
 #[cfg(feature = "shulkerbox")]
@@ -31,7 +31,6 @@ use crate::{
     },
 };
 
-// TODO: fix this leading to compile errors without 'shulkerbox' feature
 /// Compile-time evaluated value
 #[allow(missing_docs)]
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -42,17 +41,6 @@ pub enum ComptimeValue {
     MacroString(MacroString),
 }
 
-impl Display for ComptimeValue {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Self::Boolean(boolean) => write!(f, "{boolean}"),
-            Self::Integer(int) => write!(f, "{int}"),
-            Self::String(string) => write!(f, "{string}"),
-            Self::MacroString(macro_string) => write!(f, "{macro_string}"),
-        }
-    }
-}
-
 impl ComptimeValue {
     /// Returns the value as a string not containing a macro.
     #[must_use]
@@ -64,6 +52,17 @@ impl ComptimeValue {
             Self::MacroString(_) => None,
         }
     }
+
+    /// Returns the value as a [`MacroString`].
+    #[must_use]
+    pub fn to_macro_string(&self) -> MacroString {
+        match self {
+            Self::Boolean(boolean) => MacroString::String(boolean.to_string()),
+            Self::Integer(int) => MacroString::String(int.to_string()),
+            Self::String(string) => MacroString::String(string.clone()),
+            Self::MacroString(macro_string) => macro_string.clone(),
+        }
+    }
 }
 
 /// The type of an expression.
@@ -287,27 +286,29 @@ impl Primary {
                 }
             },
             Self::Indexed(indexed) => {
-                let Self::Identifier(ident) = indexed.object().as_ref() else {
-                    todo!("throw error: cannot index anything except identifiers")
-                };
-                scope
-                    .get_variable(ident.span.str())
-                    .map_or(false, |variable| match r#type {
-                        ValueType::Boolean => {
-                            matches!(
-                                variable.as_ref(),
-                                VariableData::Tag { .. } | VariableData::BooleanStorageArray { .. }
-                            )
-                        }
-                        ValueType::Integer => {
-                            matches!(
-                                variable.as_ref(),
-                                VariableData::Scoreboard { .. }
-                                    | VariableData::ScoreboardArray { .. }
-                            )
-                        }
-                        ValueType::String => false,
-                    })
+                if let Self::Identifier(ident) = indexed.object().as_ref() {
+                    scope
+                        .get_variable(ident.span.str())
+                        .map_or(false, |variable| match r#type {
+                            ValueType::Boolean => {
+                                matches!(
+                                    variable.as_ref(),
+                                    VariableData::Tag { .. }
+                                        | VariableData::BooleanStorageArray { .. }
+                                )
+                            }
+                            ValueType::Integer => {
+                                matches!(
+                                    variable.as_ref(),
+                                    VariableData::Scoreboard { .. }
+                                        | VariableData::ScoreboardArray { .. }
+                                )
+                            }
+                            ValueType::String => false,
+                        })
+                } else {
+                    false
+                }
             }
             #[cfg_attr(not(feature = "lua"), expect(unused_variables))]
             Self::Lua(lua) => {
@@ -785,9 +786,16 @@ impl Transpiler {
                 }
             }
             Primary::Indexed(indexed) => {
-                let Primary::Identifier(ident) = indexed.object().as_ref() else {
-                    todo!("can only index identifier")
-                };
+                let ident = if let Primary::Identifier(ident) = indexed.object().as_ref() {
+                    Ok(ident)
+                } else {
+                    let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                        reason: IllegalIndexingReason::NotIdentifier,
+                        expression: indexed.object().span(),
+                    });
+                    handler.receive(err.clone());
+                    Err(err)
+                }?;
                 let variable = scope.get_variable(ident.span.str());
                 #[expect(clippy::option_if_let_else)]
                 if let Some(variable) = variable.as_deref() {
@@ -801,7 +809,14 @@ impl Transpiler {
                                     target,
                                 })
                             } else {
-                                todo!("can only index scoreboard with comptime string")
+                                let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::String,
+                                    },
+                                    expression: indexed.index().span(),
+                                });
+                                handler.receive(err.clone());
+                                Err(err)
                             }
                         }
                         VariableData::ScoreboardArray { objective, targets } => {
@@ -818,10 +833,25 @@ impl Transpiler {
                                         target,
                                     })
                                 } else {
-                                    todo!("index out of bounds")
+                                    let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                        reason: IllegalIndexingReason::IndexOutOfBounds {
+                                            length: targets.len(),
+                                            index: usize::try_from(index).unwrap_or(usize::MAX),
+                                        },
+                                        expression: indexed.index().span(),
+                                    });
+                                    handler.receive(err.clone());
+                                    Err(err)
                                 }
                             } else {
-                                todo!("can only index array with comptime integer")
+                                let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::Integer,
+                                    },
+                                    expression: indexed.index().span(),
+                                });
+                                handler.receive(err.clone());
+                                Err(err)
                             }
                         }
                         VariableData::BooleanStorageArray {
@@ -842,10 +872,25 @@ impl Transpiler {
                                         r#type: StorageType::Boolean,
                                     })
                                 } else {
-                                    todo!("index out of bounds")
+                                    let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                        reason: IllegalIndexingReason::IndexOutOfBounds {
+                                            length: paths.len(),
+                                            index: usize::try_from(index).unwrap_or(usize::MAX),
+                                        },
+                                        expression: indexed.index().span(),
+                                    });
+                                    handler.receive(err.clone());
+                                    Err(err)
                                 }
                             } else {
-                                todo!("can only index array with comptime integer")
+                                let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::Integer,
+                                    },
+                                    expression: indexed.index().span(),
+                                });
+                                handler.receive(err.clone());
+                                Err(err)
                             }
                         }
                         _ => {
@@ -1022,9 +1067,16 @@ impl Transpiler {
                 self.transpile_expression_as_condition(parenthesized.expression(), scope, handler)
             }
             Primary::Indexed(indexed) => {
-                let Primary::Identifier(ident) = indexed.object().as_ref() else {
-                    todo!("can only index identifier")
-                };
+                let ident = if let Primary::Identifier(ident) = indexed.object().as_ref() {
+                    Ok(ident)
+                } else {
+                    let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                        reason: IllegalIndexingReason::NotIdentifier,
+                        expression: indexed.object().span(),
+                    });
+                    handler.receive(err.clone());
+                    Err(err)
+                }?;
                 #[expect(clippy::option_if_let_else)]
                 if let Some(variable) = scope.get_variable(ident.span.str()).as_deref() {
                     #[expect(clippy::single_match_else)]
@@ -1049,10 +1101,25 @@ impl Transpiler {
                                         )),
                                     ))
                                 } else {
-                                    todo!("index out of bounds")
+                                    let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                        reason: IllegalIndexingReason::IndexOutOfBounds {
+                                            length: paths.len(),
+                                            index: usize::try_from(index).unwrap_or(usize::MAX),
+                                        },
+                                        expression: indexed.index().span(),
+                                    });
+                                    handler.receive(err.clone());
+                                    Err(err)
                                 }
                             } else {
-                                todo!("can only index array with comptime integer")
+                                let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                    reason: IllegalIndexingReason::InvalidComptimeType {
+                                        expected: ExpectedType::Integer,
+                                    },
+                                    expression: indexed.index().span(),
+                                });
+                                handler.receive(err.clone());
+                                Err(err)
                             }
                         }
                         _ => {

src/transpile/internal_functions.rs

@@ -0,0 +1,317 @@
+//! Functions provided by the language itself.
+
+use std::{
+    ops::{Bound, Deref, RangeBounds},
+    sync::Arc,
+};
+
+use shulkerbox::prelude::Command;
+
+use serde_json::{json, Value as JsonValue};
+
+use crate::{
+    base::{source_file::SourceElement as _, VoidHandler},
+    lexical::token::{Identifier, MacroStringLiteralPart},
+    semantic::error::InvalidFunctionArguments,
+    syntax::syntax_tree::expression::{Expression, FunctionCall, Primary},
+    transpile::{
+        error::{IllegalIndexing, IllegalIndexingReason, LuaRuntimeError, UnknownIdentifier},
+        expression::{ComptimeValue, DataLocation, StorageType},
+        util::MacroString,
+        TranspileError,
+    },
+};
+
+use super::{Scope, TranspileResult, Transpiler, VariableData};
+
+/// A function that can be called from the language.
+pub type InternalFunction =
+    fn(&mut Transpiler, &Arc<Scope>, &FunctionCall) -> TranspileResult<Vec<Command>>;
+
+/// Adds all internal functions to the scope.
+pub fn add_all_to_scope(scope: &Arc<Scope>) {
+    scope.set_variable(
+        "print",
+        VariableData::InternalFunction {
+            implementation: print_function,
+        },
+    );
+}
+
+fn get_args_assert_in_range(
+    call: &FunctionCall,
+    range: impl RangeBounds<usize>,
+) -> TranspileResult<Vec<&Expression>> {
+    let args = call
+        .arguments()
+        .as_ref()
+        .map(|args| args.elements().map(Deref::deref).collect::<Vec<_>>())
+        .unwrap_or_default();
+    if range.contains(&args.len()) {
+        Ok(args)
+    } else {
+        let span = args
+            .first()
+            .and_then(|first| {
+                args.last()
+                    .map(|last| first.span().join(&last.span()).expect("invalid span"))
+            })
+            .unwrap_or_else(|| {
+                call.left_parenthesis()
+                    .span()
+                    .join(&call.right_parenthesis().span())
+                    .expect("invalid span")
+            });
+
+        let actual = args.len();
+        let expected = match range.start_bound() {
+            Bound::Excluded(excluded) => (excluded + 1 > actual).then_some(excluded + 1),
+            Bound::Included(&included) => (included > actual).then_some(included),
+            Bound::Unbounded => None,
+        }
+        .or_else(|| match range.end_bound() {
+            Bound::Excluded(&excluded) => (excluded <= actual).then_some(excluded.wrapping_sub(1)),
+            Bound::Included(&included) => (included < actual).then_some(included),
+            Bound::Unbounded => None,
+        })
+        .unwrap_or_default();
+
+        Err(TranspileError::InvalidFunctionArguments(
+            InvalidFunctionArguments {
+                expected,
+                actual: args.len(),
+                span,
+            },
+        ))
+    }
+}
+
+#[expect(clippy::too_many_lines)]
+fn print_function(
+    transpiler: &mut Transpiler,
+    scope: &Arc<Scope>,
+    call: &FunctionCall,
+) -> TranspileResult<Vec<Command>> {
+    const PARAM_COLOR: &str = "gray";
+
+    #[expect(clippy::option_if_let_else)]
+    fn get_identifier_part(
+        ident: &Identifier,
+        _transpiler: &mut Transpiler,
+        scope: &Arc<Scope>,
+    ) -> TranspileResult<(bool, Vec<Command>, JsonValue)> {
+        if let Some(var) = scope.get_variable(ident.span.str()).as_deref() {
+            match var {
+                VariableData::MacroParameter { macro_name, .. } => Ok((
+                    true,
+                    Vec::new(),
+                    json!({"text": format!("$({macro_name})"), "color": PARAM_COLOR}),
+                )),
+                VariableData::ScoreboardValue { objective, target } => Ok((
+                    false,
+                    Vec::new(),
+                    get_data_location(&DataLocation::ScoreboardValue {
+                        objective: objective.to_string(),
+                        target: target.to_string(),
+                    }),
+                )),
+                VariableData::BooleanStorage { storage_name, path } => Ok((
+                    false,
+                    Vec::new(),
+                    get_data_location(&DataLocation::Storage {
+                        storage_name: storage_name.to_string(),
+                        path: path.to_string(),
+                        r#type: StorageType::Boolean,
+                    }),
+                )),
+                _ => todo!("get_identifier_part"),
+            }
+        } else {
+            Err(TranspileError::UnknownIdentifier(UnknownIdentifier {
+                identifier: ident.span(),
+            }))
+        }
+    }
+
+    fn get_data_location(location: &DataLocation) -> JsonValue {
+        match location {
+            DataLocation::ScoreboardValue { objective, target } => {
+                json!({"score": {"name": target, "objective": objective}, "color": PARAM_COLOR})
+            }
+            DataLocation::Storage {
+                storage_name, path, ..
+            } => json!({"nbt": path, "storage": storage_name, "color": PARAM_COLOR}),
+            DataLocation::Tag { .. } => todo!("implement tag"),
+        }
+    }
+
+    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 mut contains_macro = matches!(target, MacroString::MacroString(_));
+
+    let (mut cmds, parts) = match message_expression {
+        Expression::Primary(primary) => match primary {
+            Primary::Boolean(boolean) => Ok((
+                Vec::new(),
+                vec![JsonValue::String(boolean.value().to_string())],
+            )),
+            Primary::Integer(integer) => Ok((
+                Vec::new(),
+                vec![JsonValue::String(integer.as_i64().to_string())],
+            )),
+            Primary::StringLiteral(string) => Ok((
+                Vec::new(),
+                vec![JsonValue::String(string.str_content().to_string())],
+            )),
+            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(),
+                        ))
+                    })?)],
+                ))
+            }
+            Primary::Identifier(ident) => {
+                // TODO: get_identifier_part
+                let (cur_contains_macro, cmds, part) =
+                    get_identifier_part(ident, transpiler, scope).expect("failed");
+                contains_macro |= cur_contains_macro;
+                Ok((cmds, vec![part]))
+            }
+            Primary::Indexed(indexed) => match indexed.object().as_ref() {
+                Primary::Identifier(ident) => {
+                    match scope.get_variable(ident.span.str()).as_deref() {
+                        Some(VariableData::Scoreboard { objective }) => {
+                            if let Some(ComptimeValue::String(index)) =
+                                indexed.index().comptime_eval(scope, &VoidHandler)
+                            {
+                                Ok((
+                                    Vec::new(),
+                                    vec![get_data_location(&DataLocation::ScoreboardValue {
+                                        objective: objective.to_string(),
+                                        target: index,
+                                    })],
+                                ))
+                            } else {
+                                todo!("allow macro string, but throw error when index is not constant string")
+                            }
+                        }
+                        Some(VariableData::ScoreboardArray { objective, targets }) => {
+                            if let Some(ComptimeValue::Integer(index)) =
+                                indexed.index().comptime_eval(scope, &VoidHandler)
+                            {
+                                #[expect(clippy::option_if_let_else)]
+                                if let Some(target) = usize::try_from(index)
+                                    .ok()
+                                    .and_then(|index| targets.get(index))
+                                {
+                                    Ok((
+                                        Vec::new(),
+                                        vec![get_data_location(&DataLocation::ScoreboardValue {
+                                            objective: objective.to_string(),
+                                            target: target.to_string(),
+                                        })],
+                                    ))
+                                } else {
+                                    todo!("throw error when index is out of bounds")
+                                }
+                            } else {
+                                todo!("throw error when index is not constant integer")
+                            }
+                        }
+                        Some(VariableData::BooleanStorageArray {
+                            storage_name,
+                            paths,
+                        }) => {
+                            if let Some(ComptimeValue::Integer(index)) =
+                                indexed.index().comptime_eval(scope, &VoidHandler)
+                            {
+                                #[expect(clippy::option_if_let_else)]
+                                if let Some(path) = usize::try_from(index)
+                                    .ok()
+                                    .and_then(|index| paths.get(index))
+                                {
+                                    Ok((
+                                        Vec::new(),
+                                        vec![get_data_location(&DataLocation::Storage {
+                                            storage_name: storage_name.to_string(),
+                                            path: path.to_string(),
+                                            r#type: StorageType::Boolean,
+                                        })],
+                                    ))
+                                } else {
+                                    todo!("throw error when index is out of bounds")
+                                }
+                            } else {
+                                todo!("throw error when index is not constant integer")
+                            }
+                        }
+                        _ => todo!(),
+                    }
+                }
+                _ => Err(TranspileError::IllegalIndexing(IllegalIndexing {
+                    expression: indexed.object().span(),
+                    reason: IllegalIndexingReason::NotIdentifier,
+                })),
+            },
+            Primary::MacroStringLiteral(macro_string) => {
+                let mut cmds = Vec::new();
+                let mut parts = Vec::new();
+                for part in macro_string.parts() {
+                    match part {
+                        MacroStringLiteralPart::Text(text) => {
+                            parts.push(JsonValue::String(text.str().to_string()));
+                        }
+                        MacroStringLiteralPart::MacroUsage { identifier, .. } => {
+                            let (cur_contains_macro, cur_cmds, part) =
+                                get_identifier_part(identifier, transpiler, scope)?;
+                            contains_macro |= cur_contains_macro;
+                            cmds.extend(cur_cmds);
+                            parts.push(part);
+                        }
+                    }
+                }
+                Ok((cmds, parts))
+            }
+
+            _ => todo!("print_function Primary"),
+        },
+        Expression::Binary(_) => todo!("print_function Binary"),
+    }?;
+
+    // TODO: prepend prefix with datapack name to parts and remove following
+    let print_args = if parts.len() == 1 {
+        serde_json::to_string(&parts[0]).expect("json serialization failed")
+    } else {
+        serde_json::to_string(&parts).expect("json serialization failed")
+    };
+
+    // TODO: throw correct error
+    let cmd = format!("tellraw {target} {print_args}");
+
+    let cmd = if contains_macro {
+        Command::UsesMacro(cmd.parse::<MacroString>().expect("cannot fail").into())
+    } else {
+        Command::Raw(cmd)
+    };
+
+    cmds.push(cmd);
+
+    Ok(cmds)
+}

src/transpile/lua.rs

@@ -4,13 +4,17 @@
 mod enabled {
     use std::sync::Arc;
 
-    use mlua::{Lua, Value};
+    use mlua::{Lua, Table, Value};
 
     use crate::{
         base::{self, source_file::SourceElement, Handler},
+        lexical::token::Identifier,
         syntax::syntax_tree::expression::LuaCode,
         transpile::{
-            error::{LuaRuntimeError, MismatchedTypes, TranspileError, TranspileResult},
+            error::{
+                LuaRuntimeError, MismatchedTypes, TranspileError, TranspileResult,
+                UnknownIdentifier,
+            },
             expression::{ComptimeValue, ExpectedType},
             Scope, VariableData,
         },
@@ -53,14 +57,8 @@ mod enabled {
                 )
             };
 
-            if let Err(err) = self.add_globals(&lua, scope) {
-                let err = TranspileError::LuaRuntimeError(LuaRuntimeError::from_lua_err(
-                    &err,
-                    self.span(),
-                ));
-                handler.receive(crate::Error::from(err.clone()));
-                return Err(err);
-            }
+            self.add_globals(&lua, scope)
+                .inspect_err(|err| handler.receive(err.clone()))?;
 
             let res = lua
                 .load(self.code())
@@ -95,111 +93,188 @@ mod enabled {
             self.handle_lua_result(lua_result, handler)
         }
 
-        fn add_globals(&self, lua: &Lua, scope: &Arc<Scope>) -> mlua::Result<()> {
+        fn add_globals(&self, lua: &Lua, scope: &Arc<Scope>) -> TranspileResult<()> {
             let globals = lua.globals();
 
-            let shulkerscript_globals = {
-                let table = lua.create_table()?;
-
-                let (location_path, location_start, location_end) = {
-                    let span = self.span();
-                    let file = span.source_file();
-                    let path = file.path().to_owned();
-                    let start_location = span.start_location();
-                    let end_location = span.end_location().unwrap_or_else(|| {
-                        let line_amount = file.line_amount();
-                        let column = file.get_line(line_amount).expect("line amount used").len();
-
-                        crate::base::source_file::Location {
-                            line: line_amount,
-                            column,
-                        }
-                    });
-
-                    (path, start_location, end_location)
-                };
-
-                table.set("file_path", location_path.to_string_lossy())?;
-                table.set("start_line", location_start.line)?;
-                table.set("start_column", location_start.column)?;
-                table.set("end_line", location_end.line)?;
-                table.set("end_column", location_end.column)?;
-
-                table.set("version", crate::VERSION)?;
-
-                table
-            };
+            let shulkerscript_globals = self
+                .get_std_library(lua)
+                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
 
             if let Some(inputs) = self.inputs() {
-                for x in inputs.elements() {
-                    let name = x.span.str();
-                    let value = match scope.get_variable(name).as_deref() {
-                        Some(VariableData::MacroParameter { macro_name, .. }) => {
-                            Value::String(lua.create_string(format!("$({macro_name})"))?)
-                        }
-                        Some(VariableData::Scoreboard { objective }) => {
-                            let table = lua.create_table()?;
-                            table.set("objective", objective.as_str())?;
-                            Value::Table(table)
-                        }
-                        Some(VariableData::ScoreboardValue { objective, target }) => {
-                            let table = lua.create_table()?;
-                            table.set("objective", lua.create_string(objective)?)?;
-                            table.set("target", lua.create_string(target)?)?;
-                            Value::Table(table)
-                        }
-                        Some(VariableData::ScoreboardArray { objective, targets }) => {
-                            let table = lua.create_table()?;
-                            table.set("objective", objective.as_str())?;
-                            let values = lua.create_table_from(
-                                targets
-                                    .iter()
-                                    .enumerate()
-                                    .map(|(i, target)| (i + 1, target.as_str())),
-                            )?;
-                            table.set("targets", values)?;
-                            Value::Table(table)
-                        }
-                        Some(VariableData::BooleanStorage { storage_name, path }) => {
-                            let table = lua.create_table()?;
-                            table.set("storage", lua.create_string(storage_name)?)?;
-                            table.set("path", lua.create_string(path)?)?;
-                            Value::Table(table)
-                        }
-                        Some(VariableData::BooleanStorageArray {
-                            storage_name,
-                            paths,
-                        }) => {
-                            let table = lua.create_table()?;
-                            table.set("storage", storage_name.as_str())?;
-                            let values = lua.create_table_from(
-                                paths
-                                    .iter()
-                                    .enumerate()
-                                    .map(|(i, path)| (i + 1, path.as_str())),
-                            )?;
-                            table.set("paths", values)?;
-                            Value::Table(table)
-                        }
-                        Some(VariableData::Tag { tag_name }) => {
-                            let table = lua.create_table()?;
-                            table.set("name", tag_name.as_str())?;
-                            Value::Table(table)
-                        }
-                        Some(VariableData::Function { .. }) => {
-                            todo!("allow function variable type")
-                        }
-                        None => todo!("throw correct error"),
-                    };
-                    globals.set(name, value)?;
+                for identifier in inputs.elements() {
+                    let (name, value) = self.add_input_to_globals(identifier, lua, scope)?;
+                    globals
+                        .set(name, value)
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
                 }
             }
 
-            globals.set("shulkerscript", shulkerscript_globals)?;
+            globals
+                .set("shulkerscript", shulkerscript_globals)
+                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
 
             Ok(())
         }
 
+        fn get_std_library(&self, lua: &Lua) -> mlua::Result<Table> {
+            let table = lua.create_table()?;
+
+            let (location_path, location_start, location_end) = {
+                let span = self.span();
+                let file = span.source_file();
+                let path = file.path().to_owned();
+                let start_location = span.start_location();
+                let end_location = span.end_location().unwrap_or_else(|| {
+                    let line_amount = file.line_amount();
+                    let column = file.get_line(line_amount).expect("line amount used").len();
+
+                    crate::base::source_file::Location {
+                        line: line_amount,
+                        column,
+                    }
+                });
+
+                (path, start_location, end_location)
+            };
+
+            table.set("file_path", location_path.to_string_lossy())?;
+            table.set("start_line", location_start.line)?;
+            table.set("start_column", location_start.column)?;
+            table.set("end_line", location_end.line)?;
+            table.set("end_column", location_end.column)?;
+
+            table.set("version", crate::VERSION)?;
+
+            Ok(table)
+        }
+
+        #[expect(clippy::too_many_lines)]
+        fn add_input_to_globals<'a>(
+            &self,
+            identifier: &'a Identifier,
+            lua: &Lua,
+            scope: &Arc<Scope>,
+        ) -> TranspileResult<(&'a str, Value)> {
+            let name = identifier.span.str();
+            let value = match scope.get_variable(name).as_deref() {
+                Some(VariableData::MacroParameter { macro_name, .. }) => Value::String(
+                    lua.create_string(format!("$({macro_name})"))
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                ),
+                Some(VariableData::Scoreboard { objective }) => {
+                    let table = lua
+                        .create_table()
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set("objective", objective.as_str())
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    Value::Table(table)
+                }
+                Some(VariableData::ScoreboardValue { objective, target }) => {
+                    let table = lua
+                        .create_table()
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set(
+                            "objective",
+                            lua.create_string(objective)
+                                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                        )
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set(
+                            "target",
+                            lua.create_string(target)
+                                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                        )
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    Value::Table(table)
+                }
+                Some(VariableData::ScoreboardArray { objective, targets }) => {
+                    let table = lua
+                        .create_table()
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set("objective", objective.as_str())
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    let values = lua
+                        .create_table_from(
+                            targets
+                                .iter()
+                                .enumerate()
+                                .map(|(i, target)| (i + 1, target.as_str())),
+                        )
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set("targets", values)
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    Value::Table(table)
+                }
+                Some(VariableData::BooleanStorage { storage_name, path }) => {
+                    let table = lua
+                        .create_table()
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set(
+                            "storage",
+                            lua.create_string(storage_name)
+                                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                        )
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set(
+                            "path",
+                            lua.create_string(path)
+                                .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?,
+                        )
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    Value::Table(table)
+                }
+                Some(VariableData::BooleanStorageArray {
+                    storage_name,
+                    paths,
+                }) => {
+                    let table = lua
+                        .create_table()
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set("storage", storage_name.as_str())
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    let values = lua
+                        .create_table_from(
+                            paths
+                                .iter()
+                                .enumerate()
+                                .map(|(i, path)| (i + 1, path.as_str())),
+                        )
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set("paths", values)
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    Value::Table(table)
+                }
+                Some(VariableData::Tag { tag_name }) => {
+                    let table = lua
+                        .create_table()
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    table
+                        .set("name", tag_name.as_str())
+                        .map_err(|err| LuaRuntimeError::from_lua_err(&err, self.span()))?;
+                    Value::Table(table)
+                }
+                Some(VariableData::Function { .. } | VariableData::InternalFunction { .. }) => {
+                    todo!("(internal) functions are not supported yet");
+                }
+                None => {
+                    return Err(TranspileError::UnknownIdentifier(UnknownIdentifier {
+                        identifier: identifier.span(),
+                    }));
+                }
+            };
+
+            Ok((name, value))
+        }
+
         fn handle_lua_result(
             &self,
             value: Value,

src/transpile/mod.rs

@@ -29,6 +29,9 @@ use strum::EnumIs;
 #[cfg_attr(feature = "shulkerbox", doc(inline))]
 pub use transpiler::Transpiler;
 
+#[cfg(feature = "shulkerbox")]
+pub mod internal_functions;
+
 mod variables;
 pub use variables::{Scope, VariableData};
 

src/transpile/transpiler.rs

@@ -101,7 +101,7 @@ impl Transpiler {
             let scope = self
                 .scopes
                 .entry(program_identifier)
-                .or_default()
+                .or_insert_with(Scope::with_internal_functions)
                 .to_owned();
             self.transpile_program_declarations(program, &scope, handler);
         }
@@ -129,7 +129,7 @@ impl Transpiler {
             let scope = self
                 .scopes
                 .entry(identifier_span.source_file().identifier().to_owned())
-                .or_default()
+                .or_insert_with(Scope::with_internal_functions)
                 .to_owned();
             self.get_or_transpile_function(&identifier_span, None, &scope, handler)?;
         }
@@ -441,7 +441,7 @@ impl Transpiler {
                         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_string().into())),
+                                Some(val) => Ok(Parameter::Static(val.to_macro_string())),
                                 None => {
                                     let err = TranspileError::MismatchedTypes(MismatchedTypes {
                                         expression: expression.span(),
@@ -831,60 +831,68 @@ impl Transpiler {
             .arguments()
             .as_ref()
             .map(|l| l.elements().map(Deref::deref).collect::<Vec<_>>());
-        let (location, arguments) = self.get_or_transpile_function(
-            &func.identifier().span,
-            arguments.as_deref(),
-            scope,
-            handler,
-        )?;
-        let mut function_call = format!("function {location}");
-        match arguments {
-            TranspiledFunctionArguments::Static(arguments) => {
-                use std::fmt::Write;
-                let arguments_iter = arguments.iter().map(|(ident, v)| match v {
-                    MacroString::String(s) => MacroString::String(format!(
-                        r#"{macro_name}:"{escaped}""#,
-                        macro_name = crate::util::identifier_to_macro(ident),
-                        escaped = crate::util::escape_str(s)
-                    )),
-                    MacroString::MacroString(parts) => MacroString::MacroString(
-                        std::iter::once(MacroStringPart::String(format!(
-                            r#"{macro_name}:""#,
-                            macro_name = crate::util::identifier_to_macro(ident)
-                        )))
-                        .chain(parts.clone().into_iter().map(|part| match part {
-                            MacroStringPart::String(s) => {
-                                MacroStringPart::String(crate::util::escape_str(&s).to_string())
-                            }
-                            macro_usage @ MacroStringPart::MacroUsage(_) => macro_usage,
-                        }))
-                        .chain(std::iter::once(MacroStringPart::String('"'.to_string())))
-                        .collect(),
-                    ),
-                });
-                let arguments = super::util::join_macro_strings(arguments_iter);
+        if let Some(VariableData::InternalFunction { implementation }) =
+            scope.get_variable(func.identifier().span.str()).as_deref()
+        {
+            implementation(self, scope, func).inspect_err(|err| {
+                handler.receive(err.clone());
+            })
+        } else {
+            let (location, arguments) = self.get_or_transpile_function(
+                &func.identifier().span,
+                arguments.as_deref(),
+                scope,
+                handler,
+            )?;
+            let mut function_call = format!("function {location}");
+            match arguments {
+                TranspiledFunctionArguments::Static(arguments) => {
+                    use std::fmt::Write;
+                    let arguments_iter = arguments.iter().map(|(ident, v)| match v {
+                        MacroString::String(s) => MacroString::String(format!(
+                            r#"{macro_name}:"{escaped}""#,
+                            macro_name = crate::util::identifier_to_macro(ident),
+                            escaped = crate::util::escape_str(s)
+                        )),
+                        MacroString::MacroString(parts) => MacroString::MacroString(
+                            std::iter::once(MacroStringPart::String(format!(
+                                r#"{macro_name}:""#,
+                                macro_name = crate::util::identifier_to_macro(ident)
+                            )))
+                            .chain(parts.clone().into_iter().map(|part| match part {
+                                MacroStringPart::String(s) => {
+                                    MacroStringPart::String(crate::util::escape_str(&s).to_string())
+                                }
+                                macro_usage @ MacroStringPart::MacroUsage(_) => macro_usage,
+                            }))
+                            .chain(std::iter::once(MacroStringPart::String('"'.to_string())))
+                            .collect(),
+                        ),
+                    });
+                    let arguments = super::util::join_macro_strings(arguments_iter);
 
-                let cmd = match arguments {
-                    MacroString::String(arguments) => {
-                        write!(function_call, " {{{arguments}}}").unwrap();
-                        Command::Raw(function_call)
-                    }
-                    MacroString::MacroString(mut parts) => {
-                        function_call.push_str(" {");
-                        parts.insert(0, MacroStringPart::String(function_call));
-                        parts.push(MacroStringPart::String('}'.to_string()));
-                        Command::UsesMacro(MacroString::MacroString(parts).into())
-                    }
-                };
+                    let cmd = match arguments {
+                        MacroString::String(arguments) => {
+                            write!(function_call, " {{{arguments}}}").unwrap();
+                            Command::Raw(function_call)
+                        }
+                        MacroString::MacroString(mut parts) => {
+                            function_call.push_str(" {");
+                            parts.insert(0, MacroStringPart::String(function_call));
+                            parts.push(MacroStringPart::String('}'.to_string()));
+                            Command::UsesMacro(MacroString::MacroString(parts).into())
+                        }
+                    };
 
-                Ok(vec![cmd])
+                    Ok(vec![cmd])
+                }
+                TranspiledFunctionArguments::Dynamic(mut cmds) => {
+                    function_call.push_str(" with storage shulkerscript:function_arguments");
+                    cmds.push(Command::Raw(function_call));
+                    Ok(cmds)
+                }
+                TranspiledFunctionArguments::None => Ok(vec![Command::Raw(function_call)]),
             }
-            TranspiledFunctionArguments::Dynamic(mut cmds) => {
-                function_call.push_str(" with storage shulkerscript:function_arguments");
-                cmds.push(Command::Raw(function_call));
-                Ok(cmds)
-            }
-            TranspiledFunctionArguments::None => Ok(vec![Command::Raw(function_call)]),
         }
     }
 

src/transpile/variables.rs

@@ -1,7 +1,7 @@
 #![expect(unused)]
 
 use std::{
-    collections::HashMap,
+    collections::{HashMap, VecDeque},
     fmt::Debug,
     ops::Deref,
     sync::{Arc, OnceLock, RwLock},
@@ -20,15 +20,20 @@ use crate::{
     syntax::syntax_tree::{
         expression::{Expression, Primary},
         statement::{
-            AssignmentDestination, ScoreVariableDeclaration, SingleVariableDeclaration,
-            VariableDeclaration,
+            ArrayVariableDeclaration, AssignmentDestination, ScoreVariableDeclaration,
+            SingleVariableDeclaration, TagVariableDeclaration, VariableDeclaration,
         },
+        Annotation,
     },
 };
 
 use super::{
-    error::{AssignmentError, IllegalAnnotationContent, MismatchedTypes},
+    error::{
+        AssignmentError, IllegalAnnotationContent, IllegalIndexing, IllegalIndexingReason,
+        MismatchedTypes,
+    },
     expression::{ComptimeValue, DataLocation, ExpectedType, StorageType},
+    internal_functions::InternalFunction,
     FunctionData, TranspileAnnotationValue, TranspileError, TranspileResult,
 };
 
@@ -90,6 +95,11 @@ pub enum VariableData {
         /// The paths to the booleans.
         paths: Vec<String>,
     },
+    /// Compiler internal function.
+    InternalFunction {
+        /// The implementation
+        implementation: InternalFunction,
+    },
 }
 
 #[derive(Debug, Clone, Copy, EnumAsInner)]
@@ -129,6 +139,19 @@ impl<'a> Scope<'a> {
         Arc::new(Self::default())
     }
 
+    /// Creates a new scope with internal functions.
+    #[cfg(feature = "shulkerbox")]
+    #[must_use]
+    pub fn with_internal_functions() -> Arc<Self> {
+        use super::internal_functions;
+
+        let scope = Self::new();
+
+        internal_functions::add_all_to_scope(&scope);
+
+        scope
+    }
+
     /// Creates a new scope with a parent.
     #[must_use]
     pub fn with_parent(parent: &'a Arc<Self>) -> Arc<Self> {
@@ -244,7 +267,18 @@ impl Transpiler {
                 scope,
                 handler,
             ),
-            _ => todo!("declarations other than single not supported yet: {declaration:?}"),
+            VariableDeclaration::Array(declaration) => self.transpile_array_variable_declaration(
+                declaration,
+                program_identifier,
+                scope,
+                handler,
+            ),
+            VariableDeclaration::Tag(declaration) => self.transpile_tag_variable_declaration(
+                declaration,
+                program_identifier,
+                scope,
+                handler,
+            ),
         }
     }
 
@@ -311,23 +345,14 @@ impl Transpiler {
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
     ) -> TranspileResult<Vec<Command>> {
-        let mut deobfuscate_annotations = declaration
-            .annotations()
-            .iter()
-            .filter(|a| a.has_identifier("deobfuscate"));
-
-        let deobfuscate_annotation = deobfuscate_annotations.next();
-
-        if let Some(duplicate) = deobfuscate_annotations.next() {
-            let error = TranspileError::IllegalAnnotationContent(IllegalAnnotationContent {
-                annotation: duplicate.span(),
-                message: "Multiple deobfuscate annotations are not allowed.".to_string(),
-            });
-            handler.receive(error.clone());
-            return Err(error);
-        }
-        let name =
-            self.get_data_location_identifier(declaration, program_identifier, scope, handler)?;
+        let name = self.get_data_location_identifier(
+            declaration.int_keyword().keyword,
+            declaration.identifier(),
+            declaration.annotations(),
+            program_identifier,
+            scope,
+            handler,
+        )?;
 
         let criteria = declaration
             .criteria()
@@ -350,6 +375,84 @@ impl Transpiler {
         Ok(Vec::new())
     }
 
+    fn transpile_array_variable_declaration(
+        &mut self,
+        declaration: &ArrayVariableDeclaration,
+        program_identifier: &str,
+        scope: &Arc<Scope>,
+        handler: &impl Handler<base::Error>,
+    ) -> TranspileResult<Vec<Command>> {
+        let variable_type = declaration.variable_type().keyword;
+
+        let (name, targets) =
+            self.get_array_data_location_pair(declaration, program_identifier, scope, handler)?;
+
+        match variable_type {
+            KeywordKind::Int => {
+                if !self.datapack.scoreboards().contains_key(&name) {
+                    self.datapack
+                        .register_scoreboard(&name, None::<&str>, None::<&str>);
+                }
+
+                scope.set_variable(
+                    declaration.identifier().span.str(),
+                    VariableData::ScoreboardArray {
+                        objective: name,
+                        targets,
+                    },
+                );
+            }
+            KeywordKind::Bool => {
+                scope.set_variable(
+                    declaration.identifier().span.str(),
+                    VariableData::BooleanStorageArray {
+                        storage_name: name,
+                        paths: targets,
+                    },
+                );
+            }
+            _ => unreachable!("no other variable types"),
+        }
+
+        declaration.assignment().as_ref().map_or_else(
+            || Ok(Vec::new()),
+            |assignment| {
+                self.transpile_assignment(
+                    TranspileAssignmentTarget::Identifier(declaration.identifier()),
+                    assignment.expression(),
+                    scope,
+                    handler,
+                )
+            },
+        )
+    }
+
+    fn transpile_tag_variable_declaration(
+        &mut self,
+        declaration: &TagVariableDeclaration,
+        program_identifier: &str,
+        scope: &Arc<Scope>,
+        handler: &impl Handler<base::Error>,
+    ) -> TranspileResult<Vec<Command>> {
+        let name = self.get_data_location_identifier(
+            declaration.bool_keyword().keyword,
+            declaration.identifier(),
+            declaration.annotations(),
+            program_identifier,
+            scope,
+            handler,
+        )?;
+
+        scope.set_variable(
+            declaration.identifier().span.str(),
+            VariableData::Tag { tag_name: name },
+        );
+
+        // TODO: implement assignment when map literal is implemented
+        Ok(Vec::new())
+    }
+
+    #[expect(clippy::too_many_lines)]
     pub(super) fn transpile_assignment(
         &mut self,
         destination: TranspileAssignmentTarget,
@@ -388,27 +491,176 @@ impl Transpiler {
                     Some(ComptimeValue::MacroString(s)) => {
                         todo!("indexing scoreboard with macro string: {s}")
                     }
-                    Some(_) => todo!("invalid indexing value"),
+                    Some(_) => {
+                        let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                            expression: expression.span(),
+                            reason: IllegalIndexingReason::InvalidComptimeType {
+                                expected: ExpectedType::String,
+                            },
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
+                    }
                     None => {
-                        todo!("cannot assign to scoreboard without indexing")
+                        // TODO: allow when map literals are implemented
+                        let err = TranspileError::AssignmentError(AssignmentError {
+                            identifier: identifier.span(),
+                            message: "Cannot assign to a scoreboard without indexing".to_string(),
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
                     }
                 },
-                VariableData::Function { .. } | VariableData::MacroParameter { .. } => {
+                VariableData::ScoreboardArray { objective, targets } => {
+                    match indexing_value {
+                        Some(ComptimeValue::Integer(index)) => {
+                            if let Some(target) = usize::try_from(index)
+                                .ok()
+                                .and_then(|index| targets.get(index))
+                            {
+                                Ok(DataLocation::ScoreboardValue {
+                                    objective: objective.to_string(),
+                                    target: target.to_string(),
+                                })
+                            } else {
+                                let index_span = match destination {
+                                    TranspileAssignmentTarget::Indexed(_, expr) => expr.span(),
+                                    TranspileAssignmentTarget::Identifier(_) => unreachable!(
+                                        "indexing value must be present (checked before)"
+                                    ),
+                                };
+                                let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                    expression: index_span,
+                                    reason: IllegalIndexingReason::IndexOutOfBounds {
+                                        index: usize::try_from(index).unwrap_or(usize::MAX),
+                                        length: targets.len(),
+                                    },
+                                });
+                                handler.receive(err.clone());
+                                return Err(err);
+                            }
+                        }
+                        Some(_) => {
+                            let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                expression: expression.span(),
+                                reason: IllegalIndexingReason::InvalidComptimeType {
+                                    expected: ExpectedType::Integer,
+                                },
+                            });
+                            handler.receive(err.clone());
+                            return Err(err);
+                        }
+                        None => {
+                            // TODO: implement when array literals are implemented
+                            let err = TranspileError::AssignmentError(AssignmentError {
+                                identifier: identifier.span(),
+                                message: "Cannot assign to an array without indexing".to_string(),
+                            });
+                            handler.receive(err.clone());
+                            return Err(err);
+                        }
+                    }
+                }
+                VariableData::BooleanStorageArray {
+                    storage_name,
+                    paths,
+                } => {
+                    match indexing_value {
+                        Some(ComptimeValue::Integer(index)) => {
+                            if let Some(path) = usize::try_from(index)
+                                .ok()
+                                .and_then(|index| paths.get(index))
+                            {
+                                Ok(DataLocation::Storage {
+                                    storage_name: storage_name.to_string(),
+                                    path: path.to_string(),
+                                    r#type: StorageType::Boolean,
+                                })
+                            } else {
+                                let index_span = match destination {
+                                    TranspileAssignmentTarget::Indexed(_, expr) => expr.span(),
+                                    TranspileAssignmentTarget::Identifier(_) => unreachable!(
+                                        "indexing value must be present (checked before)"
+                                    ),
+                                };
+                                let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                    expression: index_span,
+                                    reason: IllegalIndexingReason::IndexOutOfBounds {
+                                        index: usize::try_from(index).unwrap_or(usize::MAX),
+                                        length: paths.len(),
+                                    },
+                                });
+                                handler.receive(err.clone());
+                                return Err(err);
+                            }
+                        }
+                        Some(_) => {
+                            let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                                expression: expression.span(),
+                                reason: IllegalIndexingReason::InvalidComptimeType {
+                                    expected: ExpectedType::Integer,
+                                },
+                            });
+                            handler.receive(err.clone());
+                            return Err(err);
+                        }
+                        None => {
+                            // TODO: implement when array literals are implemented
+                            let err = TranspileError::AssignmentError(AssignmentError {
+                                identifier: identifier.span(),
+                                message: "Cannot assign to an array without indexing".to_string(),
+                            });
+                            handler.receive(err.clone());
+                            return Err(err);
+                        }
+                    }
+                }
+                VariableData::Tag { tag_name } => match indexing_value {
+                    Some(ComptimeValue::String(s)) => Ok(DataLocation::Tag {
+                        tag_name: tag_name.to_string(),
+                        entity: s,
+                    }),
+                    Some(ComptimeValue::MacroString(s)) => {
+                        todo!("indexing tag with macro string: {s}")
+                    }
+                    Some(_) => {
+                        let err = TranspileError::IllegalIndexing(IllegalIndexing {
+                            expression: expression.span(),
+                            reason: IllegalIndexingReason::InvalidComptimeType {
+                                expected: ExpectedType::String,
+                            },
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
+                    }
+                    None => {
+                        // TODO: allow when map literals are implemented
+                        let err = TranspileError::AssignmentError(AssignmentError {
+                            identifier: identifier.span(),
+                            message: "Cannot assign to a tag without indexing".to_string(),
+                        });
+                        handler.receive(err.clone());
+                        return Err(err);
+                    }
+                },
+                VariableData::Function { .. }
+                | VariableData::MacroParameter { .. }
+                | VariableData::InternalFunction { .. } => {
                     let err = TranspileError::AssignmentError(AssignmentError {
                         identifier: identifier.span(),
                         message: format!(
                             "Cannot assign to a {}.",
-                            if matches!(target.as_ref(), VariableData::Function { .. }) {
-                                "function"
-                            } else {
-                                "function argument"
+                            match target.as_ref() {
+                                VariableData::Function { .. } => "function",
+                                VariableData::MacroParameter { .. } => "macro parameter",
+                                VariableData::InternalFunction { .. } => "internal function",
+                                _ => unreachable!(),
                             }
                         ),
                     });
                     handler.receive(err.clone());
                     Err(err)
                 }
-                _ => todo!("implement other variable types"),
             }?;
             self.transpile_expression(expression, &data_location, scope, handler)
         } else {
@@ -423,13 +675,14 @@ impl Transpiler {
 
     fn get_data_location_identifier(
         &mut self,
-        declaration: &ScoreVariableDeclaration,
+        variable_type: KeywordKind,
+        identifier: &Identifier,
+        annotations: &VecDeque<Annotation>,
         program_identifier: &str,
         scope: &Arc<Scope>,
         handler: &impl Handler<base::Error>,
     ) -> TranspileResult<String> {
-        let mut deobfuscate_annotations = declaration
-            .annotations()
+        let mut deobfuscate_annotations = annotations
             .iter()
             .filter(|a| a.has_identifier("deobfuscate"));
 
@@ -453,6 +706,7 @@ impl Transpiler {
                         .comptime_eval(scope, handler)
                         .and_then(|val| val.to_string_no_macro())
                     {
+                        // TODO: change invalid criteria if boolean
                         if !crate::util::is_valid_scoreboard_objective_name(&name_eval) {
                             let error = TranspileError::IllegalAnnotationContent(IllegalAnnotationContent {
                                                     annotation: deobfuscate_annotation.span(),
@@ -471,9 +725,7 @@ impl Transpiler {
                         Err(error)
                     }
                 }
-                TranspileAnnotationValue::None => {
-                    Ok(declaration.identifier().span.str().to_string())
-                }
+                TranspileAnnotationValue::None => Ok(identifier.span.str().to_string()),
                 TranspileAnnotationValue::Map(_) => {
                     let error =
                         TranspileError::IllegalAnnotationContent(IllegalAnnotationContent {
@@ -488,7 +740,7 @@ impl Transpiler {
         } else {
             let hashed = md5::hash(program_identifier).to_hex_lowercase();
             let name = "shu_values_".to_string() + &hashed;
-            let identifier_name = declaration.identifier().span.str();
+            let identifier_name = identifier.span.str();
             let scope_ident = self.temp_counter;
             self.temp_counter = self.temp_counter.wrapping_add(1);
             let mut target = md5::hash(format!(
@@ -634,6 +886,97 @@ impl Transpiler {
         }
     }
 
+    fn get_array_data_location_pair(
+        &mut self,
+        declaration: &ArrayVariableDeclaration,
+        program_identifier: &str,
+        scope: &Arc<Scope>,
+        handler: &impl Handler<base::Error>,
+    ) -> TranspileResult<(String, Vec<String>)> {
+        let mut deobfuscate_annotations = declaration
+            .annotations()
+            .iter()
+            .filter(|a| a.has_identifier("deobfuscate"));
+
+        let variable_type = declaration.variable_type().keyword;
+
+        let deobfuscate_annotation = deobfuscate_annotations.next();
+
+        if let Some(duplicate) = deobfuscate_annotations.next() {
+            let error = TranspileError::IllegalAnnotationContent(IllegalAnnotationContent {
+                annotation: duplicate.span(),
+                message: "Multiple deobfuscate annotations are not allowed.".to_string(),
+            });
+            handler.receive(error.clone());
+            return Err(error);
+        }
+        if let Some(deobfuscate_annotation) = deobfuscate_annotation {
+            let deobfuscate_annotation_value =
+                TranspileAnnotationValue::from(deobfuscate_annotation.assignment().value.clone());
+
+            match deobfuscate_annotation_value {
+                TranspileAnnotationValue::None => {
+                    let ident_str = declaration.identifier().span.str();
+                    let name = if matches!(variable_type, KeywordKind::Int) {
+                        ident_str.to_string()
+                    } else {
+                        format!(
+                            "{namespace}:{ident_str}",
+                            namespace = self.main_namespace_name
+                        )
+                    };
+
+                    let len = declaration.size().as_i64();
+                    let targets = (0..len).map(|i| i.to_string()).collect();
+                    Ok((name, targets))
+                }
+                TranspileAnnotationValue::Map(map) => {
+                    todo!("allow map deobfuscate annotation for array variables")
+                }
+                TranspileAnnotationValue::Expression(_) => {
+                    let error =
+                        TranspileError::IllegalAnnotationContent(IllegalAnnotationContent {
+                            annotation: deobfuscate_annotation.span(),
+                            message: "Deobfuscate annotation value must be a map or none."
+                                .to_string(),
+                        });
+                    handler.receive(error.clone());
+                    Err(error)
+                }
+            }
+        } else {
+            let hashed = md5::hash(program_identifier).to_hex_lowercase();
+            let name = if matches!(variable_type, KeywordKind::Int) {
+                "shu_values_"
+            } else {
+                "shulkerbox:values_"
+            }
+            .to_string()
+                + &hashed;
+            let identifier_name = declaration.identifier().span.str();
+            let scope_ident = self.temp_counter;
+            self.temp_counter = self.temp_counter.wrapping_add(1);
+            let len = declaration.size().as_i64();
+            let targets = (0..len)
+                .map(|i| {
+                    let mut target = md5::hash(format!(
+                        "{scope_ident}\0{identifier_name}\0{i}\0{shadowed}",
+                        shadowed = scope.get_variable_shadow_count(identifier_name)
+                    ))
+                    .to_hex_lowercase();
+
+                    if matches!(variable_type, KeywordKind::Int) {
+                        target.split_off(16);
+                    }
+
+                    target
+                })
+                .collect();
+
+            Ok((name, targets))
+        }
+    }
+
     /// Move data from location `from` to location `to`.
     ///
     /// # Errors