io.md

std.io

Basic input/output operations - console output, file I/O, and type-to-string conversion.

All functions are backed by the Rust runtime (ember).

Functions

print(s: String) -> Void

Prints a string followed by a newline.

print_no_newline(s: String) -> Void

Prints a string without a trailing newline.

print_int(i: Int) -> Void

Prints an integer.

print_float(f: Float) -> Void

Prints a floating-point number.

print_bool(b: Bool) -> Void

Prints true or false.

flush() -> Void

Flushes the stdout buffer.

read_line() -> String

Reads a line from standard input. Returns an empty string on EOF.

read_file(path: String) -> String

Reads the entire contents of a file as a string. Returns an empty string if the file is not found or empty.

write_file(path: String, content: String) -> Int

Writes content to path. Returns 0 on success, non-zero on failure.

append_file(path: String, content: String) -> Int

Appends content to the file at path. Returns 0 on success, non-zero on failure.

file_exists(path: String) -> Bool

Returns true if the file at path exists.

file_size(path: String) -> Int

Returns the size of the file at path in bytes. Returns -1 on error.

delete_file(path: String) -> Bool

Deletes the file at path. Returns true on success.

rename_file(old: String, new: String) -> Bool

Renames/moves a file from old to new. Returns true on success.

to_string(val: Int) -> String

Converts an integer to its string representation.

float_to_string(val: Float) -> String

Converts a float to its string representation.

bool_to_string(val: Bool) -> String

Converts a boolean to "true" or "false".

Examples

load std.io

io.print("hello, world")
io.print_no_newline("count: ")
io.print_int(42)
io.print_float(3.14)
io.print_bool(true)

let content = io.read_file("data.txt")
let ok = io.write_file("out.txt", "data")
let line = io.read_line()
let s = io.to_string(42)