C△ Keyword Reference: All Language Keywords and Operators

Complete reference for every keyword in C△, including type, control flow, memory, module, and assembly keywords, plus deprecated C11 keywords.

Some keywords listed here are part of the language design but are not yet implemented in the current compiler — notably auto, tuple, lamb, and autoremove. See Compiler Status for the full list.

C△ inherits all standard C11 keywords and adds new ones for its type system, memory management, module system, and assembly integration. Keywords marked as deprecated will raise a SyntaxError at compile time — remove or replace them before your program will compile.

Type Keywords

Use these keywords to declare the type of a variable, parameter, or return value. C△ extends the standard C11 numeric types with first-class string, dynamic-type auto, and two collection types.

Keyword	Description
int	Signed integer
char	Single character / byte
float	Single-precision float
double	Double-precision float
void	No type / no return
short	Short integer
long	Long integer
signed	Explicitly signed integer
unsigned	Unsigned integer
string	First-class string type
auto	Dynamic / inferred type
dynam	Dynamic array
tuple	Dynamic heterogeneous list

Structure Keywords

Use these keywords to define named types, namespaces, and type aliases.

Keyword	Description
struct	Plain struct (no inheritance)
space	Library namespace declaration
typed	Typed struct (with inheritance)
typedef	C11 type alias
union	C11 union
enum	C11 enumeration

typed structs support inheritance, while plain struct does not. Use typed when you need a struct to extend another struct’s fields.

Control Flow

These keywords control the execution path through your program. They behave identically to their C11 counterparts.

Keyword	Description
if / else	Conditional branching
while	While loop
for	For loop
do	Do-while loop
switch / case / default	Switch statement
break	Break out of loop/switch
continue	Skip to next iteration
return	Return from function
goto	C11 goto

Variables declared in the init clause of a for loop are scoped to that loop body — they are not visible in the enclosing function scope.

Memory Keywords

C△ gives you fine-grained control over heap memory. You can manage memory manually with allocate and free, or opt into automatic last-use deallocation with autoremove.

Keyword	Description
allocate	Heap allocation (allocate type name [size])
free	Manual heap deallocation
autoremove	Heap alloc freed at last use (simulation pass)

Use autoremove to let the compiler’s simulation pass insert free calls automatically at the last point each pointer is used. This eliminates a whole class of memory leaks without requiring a garbage collector.

Module / Import Keywords

These keywords let you bring external library symbols into scope, expose namespaces globally, and even replace built-in syntax with library-provided alternatives.

Keyword	Description
using	Import a symbol from a library
expose	Globalize a library or namespace
@	Explicit namespace access operator
overwrite	Overwrite base syntax with library syntax

// Import the 'println' symbol from the 'io' library
using io.println;

// Access a symbol explicitly with the @ operator
io@println("hello");

// Expose an entire namespace into the current scope
expose io;

Other Keywords

These keywords cover inline assembly, lambdas, struct lifecycle functions, and standard C11 qualifiers.

Keyword	Description
asm	Inline assembly block
lamb	Named lambda
self	Optional struct self-reference
init	Struct constructor lifecycle function
end	Struct destructor lifecycle function
sizeof	C11 size operator
const	Constant qualifier
volatile	Volatile qualifier
static	Static storage
extern	External linkage
inline	Inline hint
register	Register hint

Use init and end to define constructor and destructor lifecycle functions on your structs. The compiler calls init when the struct is created and end when it goes out of scope or is freed.

Deprecated Keywords

The following C11 keywords are not supported in C△ and will immediately raise a SyntaxError when the compiler encounters them. Remove or replace any of these keywords before compiling.

Keyword	Reason
auto(C11 meaning)	Repurposed as dynamic type inference in C△
restrict	Removed
_Bool	Removed
_Complex	Removed
_Imaginary	Removed