Console IO

Type-safe wrappers for Standard Input and Output.

Concept & Motivation

The standard <stdio.h> library is fraught with danger. printf relies on the user to manually match types, leading to runtime errors, while scanf is notorious for buffer overflows and leaving the input stream in undefined states.

Camelot replaces these with a strictly typed, memory-safe I/O layer. We prioritize explicit allocation for input and type verification for output.

---

API Reference

io.scan

Reads a line of text from standard input (stdin) into an Arena.

String scan(Arena *a, u64 cap);

• Safety: This function is buffer-overflow-proof. It reads until a newline \n or until the allocated capacity is reached.

• Compatibility: Silently consumes Carriage Returns (\r) to ensure consistent behavior across Windows and Linux.

Behavior

• Default (cap = 0): Allocates a safe default of 4KB (4096 bytes).

• Explicit (cap > 0): Allocates exactly cap bytes. Use this for constrained environments (e.g., reading a PIN).

Example

// Standard Usage
String name = io.scan(&arena, 0);

// Constrained Usage
String pin = io.scan(&arena, 5); // 4 digits + null terminator

io.print

Formats and writes to stdout.

void print(const char *fmt, ...);

Replaces printf with a safe subset of specifiers.

Specifier	Type	Description
%S	String	Prints Camelot strings.
%s	char*	Prints unsafe C-Strings.
%i	int	Prints signed 32-bit integers.
%f	double	Prints 64-bit floats.
%%	N/A	Prints a literal %.

Why %% instead of just %?

The % character is reserved as the Format Trigger. When the parser sees a %, it stops printing and looks for a variable to format.

If you wrote "100% complete", the parser would try to find a format specifier starting with c (from "complete") and fail. By using %%, you explicitly tell the parser: "Escape the trigger and print the raw symbol". This follows the standard C convention, preserving familiarity.

io.put

Writes a raw Camelot string to stdout.

• Zero Allocation: Writes directly to the file descriptor without intermediate buffers.

void put(String s);