API Repl

API REPL

Interactive read-eval-print loop primitives for building console-style applications. The REPL module manages a scrolling text display with command-line input and history.

picocalc.repl

Functions

picocalc.repl.readline()

Non-blocking read of a single input event. Call this in a loop to build an interactive prompt. Handles keyboard input, scrolling (up/down arrows), backspace, and system menu detection internally.

• Parameters: None
• Returns: (string or nil) The input line when Enter is pressed, or nil on Esc or when no complete line is ready yet

while true do
    local line = picocalc.repl.readline()
    if line then
        picocalc.repl.print("> " .. line)
        -- process the command
    end
end

---

picocalc.repl.print(...)

Print values to the REPL output area. Accepts multiple arguments which are converted to strings and separated by tabs. Supports nil, boolean, number, string, table, function, and userdata types.

• Parameters:
  • ... (any): One or more values to print
• Returns: None

picocalc.repl.print("Hello", 42, true)
-- Output: Hello	42	true

---

picocalc.repl.clear()

Clear all text from the REPL display and reset the scroll position.

• Parameters: None
• Returns: None

picocalc.repl.clear()
picocalc.repl.print("Screen cleared.")

---

picocalc.repl.echo(enabled)

Enable or disable input echo. When disabled, typed characters are not displayed on screen. Useful for password prompts or hidden input.

• Parameters:
  • enabled (boolean): true to show typed characters, false to hide them
• Returns: None

picocalc.repl.echo(false)
picocalc.repl.print("Enter password:")
local password = nil
while not password do
    password = picocalc.repl.readline()
end
picocalc.repl.echo(true)