Keywords

AdeshLang documents 84 language keywords here. Every identifier that matches one of these spellings is tokenized as the corresponding keyword token rather than as an ordinary identifier, so none of them may be used as a variable, function, type, or parameter name.

Each keyword below links to a reference with an explanation, syntax/example, and use cases.

Case sensitivity

Keyword matching is case sensitive. int and Int are two distinct reserved spellings (both map to the same integer-type token), and Int is reserved separately from the lowercase int. See int and Int.

Reserved keywords by category

#	Keyword	Category	Summary	Page
1	type	Type System & Declarations	Declares a type alias or custom type.	type
2	abstract	Type System & Declarations	Marks a type/member as abstract (no direct instantiation).	abstract
3	sealed	Type System & Declarations	Restricts subtyping to a closed set.	sealed
4	interface	Type System & Declarations	Declares an interface (contract).	interface
5	implements	Type System & Declarations	Declares that a type implements an interface.	implements
6	struct	Type System & Declarations	Declares a structure type.	struct
7	enum	Type System & Declarations	Declares an enumeration.	enum
8	let	Type System & Declarations	Binds a variable (immutable by default).	let
9	const	Type System & Declarations	Declares a compile-time constant.	const
10	fn	Type System & Declarations	Declares a function.	fn
11	return	Control Flow	Returns a value from a function.	return
12	if	Control Flow	Conditional branch.	if
13	else	Control Flow	Alternative branch of if.	else
14	elif	Control Flow	Else-if chain branch.	elif
15	do	Control Flow	do...while loop body introducer.	do
16	while	Control Flow	Conditional loop.	while
17	break	Control Flow	Exits the nearest loop.	break
18	continue	Control Flow	Skips to the next loop iteration.	continue
19	jump	Control Flow	Unconditional/local jump (context-specific).	jump
20	extend	Object-Oriented Programming	Retroactive extension — extend on Type / extend Name on Type (no VTable, monomorphic).	extend
21	extends	Object-Oriented Programming	Single-inheritance class header — class Dog extends Animal.	extends
22	extern	FFI & Linkage	Declares external/FFI linkage.	extern
23	private	Object-Oriented Programming	Most restrictive visibility modifier.	private
24	protected	Object-Oriented Programming	Inheritance-aware visibility modifier.	protected
25	public	Object-Oriented Programming	Fully visible access modifier.	public
26	super	Object-Oriented Programming	References the parent type/member.	super
27	on	Object-Oriented Programming	Mandatory target marker in extend … on Type.	on
28	for	Control Flow	Iterator loop.	for
29	in	Control Flow	Iteration membership clause.	in
30	of	Control Flow	Value-iteration clause.	of
31	true	Boolean & Null Literals	Boolean true literal.	true
32	false	Boolean & Null Literals	Boolean false literal.	false
33	null	Boolean & Null Literals	Null reference literal.	null
34	and	Logical & Type Operators	Logical AND operator.	and
35	or	Logical & Type Operators	Logical OR operator.	or
36	not	Logical & Type Operators	Logical NOT operator.	not
37	instanceof	Logical & Type Operators	Runtime type test.	instanceof
38	typeof	Logical & Type Operators	Compile-time type query.	typeof
39	class	Object-Oriented Programming	Declares a class.	class
40	new	Object-Oriented Programming	Allocates/constructs an instance.	new
41	this	Object-Oriented Programming	Reference to the current instance.	this
42	self	Object-Oriented Programming	Reference to the current type/self receiver.	self
43	uint	Primitive Type Keywords	Unsigned integer type keyword.	uint
44	int	Primitive Type Keywords	Signed integer type keyword.	int
45	Int	Primitive Type Keywords	Case-sensitive alias mapping to the integer type token.	Int
46	static	Object-Oriented Programming	Member is associated with the type, not an instance.	static
47	constructor	Object-Oriented Programming	Lexed but rejected by the parser; use the class name instead.	constructor
48	get	Object-Oriented Programming	Property getter accessor.	get
49	set	Object-Oriented Programming	Property setter accessor.	set
50	operator	Object-Oriented Programming	Declares an overloaded operator.	operator
51	import	Modules & Imports	Imports a module or symbol.	import
52	as	Modules & Imports	Renames an imported/converted symbol.	as
53	export	Modules & Imports	Exports a symbol from a module.	export
54	from	Modules & Imports	Names the source module in an import.	from
55	default	Modules & Imports	Default export/import.	default
56	try	Error Handling	Begins a protected block.	try
57	catch	Error Handling	Catches a thrown error.	catch
58	throw	Error Handling	Raises an error.	throw
59	async	Async & Concurrency	Marks a function/value as asynchronous.	async
60	await	Async & Concurrency	Awaits an async value.	await
61	spawn	Async & Concurrency	Spawns a concurrent task.	spawn
62	match	Control Flow	Pattern-matching expression.	match
63	decorator	Metaprogramming & Compile-time	Declares/attaches a decorator.	decorator
64	readonly	Object-Oriented Programming	Marks a field as read-only.	readonly
65	raw	Metaprogramming & Compile-time	Raw string/verbatim marker.	raw
66	vec	Primitive Type Keywords	Vector type keyword.	vec
67	region	Memory & Safety	Declares a memory region.	region
68	defer	Memory & Safety	Schedules scope-exit cleanup.	defer
69	unsafe	Memory & Safety	Marks an unchecked/unsafe block.	unsafe
70	share	Memory & Safety	Shares a reference.	share
71	strong	Memory & Safety	Strong reference qualifier.	strong
72	weak	Memory & Safety	Weak reference qualifier.	weak
73	alloc	Memory & Safety	Allocates memory.	alloc
74	free	Memory & Safety	Frees memory.	free
75	compile	Metaprogramming & Compile-time	Compile-time evaluation block.	compile
76	runtime	Metaprogramming & Compile-time	Runtime-evaluation block/marker.	runtime
77	typecheck	Metaprogramming & Compile-time	Compile-time type assertion.	typecheck
78	emit	Metaprogramming & Compile-time	Emits code/directive.	emit
79	require	Metaprogramming & Compile-time	Compile-time precondition.	require
80	test	Testing	Declares a test.	test
81	ignore	Testing	Marks a test to be ignored.	ignore
82	expect_fail	Testing	Marks a test expected to fail.	expect_fail
83	proceed	Metaprogramming & Compile-time	Decorator continuation — call.proceed() inside runtime phase.	proceed
84	_	Wildcard / Placeholder	Wildcard/placeholder token (not an identifier).	_ (underscore)

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Special directive: $cImport

In addition to the 84 documented keywords above, the lexer recognizes a single special directive, $cImport, which is tokenized as the CImport token and used for FFI/C interop. It is not counted among the 84 identifier keywords because it begins with $ and is not part of the identifier-keyword mapping table. See FFI for usage.

$cImport "stdio.h";

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Notes on parser support

Several reserved tokens have narrow or context-specific parser support in the current implementation. Where that is the case, the dedicated page says so explicitly:

• constructor is lexed as a keyword but the parser explicitly rejects it. The supported constructor form is a method named after the class. See constructor.
• _ is a wildcard/placeholder token, not an ordinary identifier, and cannot be used as a binding name in the usual way. See _ (underscore).
• Int is case-sensitive and distinct from int; both map to the same integer-type token. See Int.
• A number of memory-safety and metaprogramming keywords (region, share, strong, weak, alloc, free, compile, runtime, typecheck, emit, require, jump) are reserved for current or experimental features and may have limited parser support.
• extend without on — writing extend Type { … } is a compile error; always use extend on Type or extend Name on Type. See extend and on.
• proceed is only meaningful as call.proceed() inside a decorator runtime(call) phase. See proceed.