Questions and keyboard input
Input is information a person gives your program. The prompt is the question it shows; the reply is the answer. The host may show a text question or a graphical input box. An overlay is a box displayed over the existing picture.
Inclusive bounds include the endpoints: a minimum of 1 and maximum of 5 allow 1 and 5 too. Finite excludes infinity and invalid numeric values. Trimming whitespace removes spaces and similar characters at the start and end. Normalizing changes an accepted spelling to one agreed form, such as the reply "2,5" becoming 2.5.
Exponent notation in a number reply, such as 1e2, means one times ten to the power two: 100. A sign is + or -. These are rules for answering a question; they do not make 1e2 a valid Pliro source-number literal. A particular input box may restrict what you can type.
Input functions
| English call | Canonical ID | Returns | Requirements |
|---|---|---|---|
ask(prompt) |
input.readLine |
Text |
prompt is Text. |
askNumber(prompt, minimum, maximum) |
input.readNumber |
Number |
Prompt is Text; finite ordered numeric bounds. |
askYesNo(prompt) |
input.readBoolean |
Boolean |
prompt is Text. |
choose(prompt, options) |
input.choose |
Text |
A non-empty list of at most 100 unique, non-blank text options. |
Input waits cooperatively while the host displays a console question or
graphical overlay. The runtime validates and converts the reply. A numeric
answer must fall inside the inclusive bounds. Number replies are trimmed; one
decimal comma with no decimal point is normalized to a point. The finite numeric
reply parser also accepts an optional sign and exponent notation, although a
particular host control may restrict which characters can be typed. This input
grammar does not change Pliro’s narrower source-number literal grammar. A choice
result is exactly one supplied option string. Option uniqueness is exact and
case-sensitive.
Console yes/no input accepts true, yes, y, waar, ja, j, or 1 for
true and false, no, n, onwaar, nee, or 0 for false, ignoring case
and surrounding whitespace. Graphical hosts present bounded yes/no and choice
controls instead.
# language: en
let name = ask("What is your name?")
let age = askNumber("How old are you?", 5, 120)
let project = choose("What shall we make?", ["game", "drawing", "robot"])
let ready = askYesNo("Ready to start?")
if not ready:
say "See you next time, " + name + "!"
exitApp()
say name, "is", age, "and chose", project
Replies are bounded to 64 KiB of valid UTF-8. Date input is not implemented
because Pliro does not yet have a specified Date value.
| English call | Canonical ID | Returns |
|---|---|---|
keyDown(key) |
input.keyDown |
Boolean |
key is non-empty Text. The portable game names are left, right, up,
down, and space. Native graphical hosts additionally recognize common names
such as enter, escape or esc, backspace, and individual ASCII letters
and digits. A host that does not expose a requested key reports it as not down.
if keyDown("left"):
set x = x - speed
Keyboard polling is a host-mediated graphical capability; it does not read the
host keyboard directly from the interpreter.