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IO

The io module provides input/output operations for the Crux programming language.

Installation​

use print, println, scan from "crux:io";

Functions​

print​

Writes a string representation of a value to stdout without a newline.

print("Hello")      // prints: Hello
print(42)           // prints: 42
print([1, 2, 3])   // prints: [1, 2, 3]

Parameters:

  • value (Any): The value to print

Returns: Nil

println​

Writes a string representation of a value to stdout followed by a newline.

println("Hello")      // prints: Hello\n
println(42)           // prints: 42\n

Parameters:

  • value (Any): The value to print

Returns: Nil

Writes a string representation of a value to a specified channel without a newline.

print_to("stdout", "Hello")  // prints to stdout
print_to("stderr", "Error")   // prints to stderr

Parameters:

  • channel (String): The channel ("stdout" or "stderr")
  • value (Any): The value to print

Returns: Result<Nil>

Errors: Invalid channel, or error writing to stream.

println_to​

Writes a string representation of a value to a specified channel followed by a newline.

println_to("stdout", "Hello")  // prints to stdout with newline
println_to("stderr", "Error")   // prints to stderr with newline

Parameters:

  • channel (String): The channel ("stdout" or "stderr")
  • value (Any): The value to print

Returns: Result<Nil>

Errors: Invalid channel, or error writing to stream.

scan​

Reads exactly one character from stdin, discarding the rest of the line.

let c = scan()  // reads single character

Returns: Result<String>

Errors: Unexpected end of input on stdin.

scanln​

Reads a line from stdin up to (and excluding) the newline character.

let line = scanln()  // reads entire line

Returns: Result<String>

Errors: Failed to allocate buffer for input, or error reading from stdin.

nscan​

Reads up to n characters from stdin, stopping early at newline.

let input = nscan(10)  // reads up to 10 characters

Parameters:

  • n (Int): Maximum number of characters to read

Returns: Result<String>

Errors: n must be a positive integer, failed to allocate buffer, or error reading from stdin.

scan_from​

Reads exactly one character from a specified channel, discarding the rest of the line.

let c = scan_from("stdin")  // reads single character from stdin

Parameters:

  • channel (String): The channel ("stdin")

Returns: Result<String>

Errors: Invalid channel, or unexpected end of input on channel.

scanln_from​

Reads a line from a specified channel up to (and excluding) the newline character.

let line = scanln_from("stdin")  // reads line from stdin

Parameters:

  • channel (String): The channel ("stdin")

Returns: Result<String>

Errors: Invalid channel, failed to allocate buffer, or error reading from channel.

nscan_from​

Reads up to n characters from a specified channel, stopping early at newline.

let input = nscan_from("stdin", 10)  // reads up to 10 characters

Parameters:

  • channel (String): The channel ("stdin")
  • n (Int): Maximum number of characters to read

Returns: Result<String>

Errors: Invalid channel, n must be a positive integer, failed to allocate buffer, or error reading from channel.