x-lang

← Index

x/type/io

Input/output on the Io class: write/display (also bare), read/read-char, the to-string captures, and the REPL hooks.

ns io de-registered except write/display (kept bare via the keep-list); the other six are Io-only. Reader-context/hot callers fetch-and-cache.

Class Io

(Io write v)

Write a value in machine-readable form (strings quoted, etc.). Also available bare as the fundamental output verb.

Parameters:

Returns: ANY — nil

(Io display v)

Display a value in human-readable form (strings unquoted). Also available bare as the fundamental output verb.

Parameters:

Returns: ANY — nil

(Io read)

Read and parse one expression from stdin.

The read primitive answers the EOF sentinel, %token-eof, at end of input, so that a () in the input is a value; this method answers () there for callers that loop until nil.

Returns: ANY — The parsed expression, or () at end of input

(Io read-char)

Read one character from stdin.

Returns: ANY — The character, or () at end of input

(Io write-to-str v)

Capture write output as a string (write form: strings quoted).

Parameters:

Returns: STRING — The machine-readable rendering of V

(Io display-to-str v)

Capture display output as a string (display form: strings unquoted).

Parameters:

Returns: STRING — The human-readable rendering of V

(Io error-line)

The source line number where the most recent error was raised. Frozen at raise time, so it is accurate read from inside a guard handler; between errors it retains the last one (boot itself catches some, so it is rarely 0).

Returns: INT — Line number

(Io error-file)

The source file path where the most recent error was raised, or “” when it arose from stdin/REPL input rather than an included file. Frozen at raise time (see error-line).

Returns: STRING — File path

(Io repl-read)

Read one expression for the REPL, applying its read conventions.

Returns: ANY — The parsed expression