Nitpick Low-Level Hardware & OS Integration

Nitpick is designed for systems-level control. It exposes direct access to hardware and operating system capabilities through explicit, highly-auditable syntactic mechanisms.

1. System Calls (sys Builtins)

Nitpick categorizes direct syscall invocation into three increasingly permissive tiers, each mapped to different safety guarantees. This allows security auditors to immediately track dangerous behavior.

• sys(CONST, args...)
  • Safe Tier: Allows access to a curated whitelist of ~55 non-destructive syscalls.
  • The first argument must be a named constant representing the syscall (e.g. sys(READ, ...)).
  • Returns a Result<int64>.
• sys!!(CONST, args...)
  • Full Tier: Allows access to all ~370+ syscalls on the OS (e.g. FORK, EXEC).
  • The first argument must still be a named constant.
  • Returns a Result<int64>.
• sys!!!(expr, args...)
  • Raw Tier: Complete escape hatch. The syscall identifier can be any int64 expression (computed at runtime), rather than a constant.
  • Returns a bare int64, completely bypassing the Result<T> safety wrapper. This is heavily flagged during audit.

2. Pointers and Memory

Unlike C, where pointers use the * operator ambiguously (for both multiplication and dereferencing), Nitpick explicitly separates these operators visually to prevent parser ambiguity and improve readability.

• -> : Type Annotation & Field Access.
  • In a type signature, it means “pointer to”. (e.g., int32-> means int32*).
  • In an expression, it acts like C’s arrow operator (dereference and field access).
• @ : Address Of. Returns the pointer address of a variable (like C’s &).
• <- : Deep Dereference. Dereferences the entire pointer, extracting the value.

int32:x = 42i32;
int32->:ptr = @x;       // Address-of
int32:val = <-ptr;      // Full dereference

(Note: In extern blocks defining C-FFI functions, the traditional * symbol is used for thin pointers to remain compatible with C headers).

3. Inline Assembly

For bare-metal tuning, Nitpick allows LLVM-mapped inline assembly blocks.

• asm!!<T>(arch, code, constraints, args...) : Evaluates assembly and maps negative return values to a Result<T> error.
• asm!!!<T>(arch, code, constraints, args...) : Evaluates assembly and returns bare T values directly.

(See asm_specs.txt for full assembly constraints and mapping rules).