math and console

math

Constants ✅

math.pi     3.141592653589793
math.e      2.718281828459045
math.tau    6.283185307179586

These fold to their literal value at compile time, so they cost nothing at runtime:

temp turns: num = math.pi * 2;
motion.forward(10 * math.pi);

math.pow ⛔

math.pow(base: num, exponent: num) -> num

Declared with an empty body and no opcode. It type-checks and produces nothing. The ** operator has the same gap and is worse — it lowers silently to an empty literal, so you get a wrong answer with no error.

Write it out:

proc pow(base: num, exp: num) -> num {
    temp result: num = 1;
    for (i, exp) {
        result = result * base;
    }
    return result;
}

That covers whole-number exponents, which is most of what a Scratch project needs. For fractional powers, Scratch’s [sqrt v] of () block is the practical route — bind it yourself:

proc mathop(@opcode = "operator_mathop", operator: str, num: num) -> num {}

temp root: num = mathop("sqrt", 16);

Note

operator_mathop also covers abs, floor, ceiling, sqrt, sin, cos, tan, asin, acos, atan, ln, log, e ^, and 10 ^. It is not in the stdlib yet, so binding it yourself is the current answer for all of them.

What is missing

No random, min, max, abs, round, floor, or trigonometry. Scratch has blocks for all of these; the stdlib has not wrapped them. Bind the opcodes directly:

proc random(@opcode = "operator_random", from: num, to: num) -> num {}
proc round(@opcode = "operator_round", value: num) -> num {}

temp roll: num = random(1, 6);

console

Danger

The whole console namespace is unimplemented. log, warn and error resolve to katnip_* opcodes with no codegen; input is a yields procedure with no lowering. All four type-check and then fail the build.

You will see console.log in several example files. Those examples do not build.

console.log(msg: str) -> void       ⛔
console.warn(msg: str) -> void      ⛔
console.error(msg: str) -> void     ⛔
console.input(prompt: str) -> str   ⛔

What to use instead

For output, say it:

looks.say(f"score is {score}", 1);

Or keep a log list, which persists and is scrollable:

public logLines: list<str> = [];

proc log(msg: str) -> void {
    logLines.add(msg);
    logLines.show();
}

For input, use the sensing pair that console.input was meant to wrap:

sensing.ask("What is your name?");
temp name: str = sensing.answer();
looks.say(f"Welcome, {name}!", 2);

console.input cannot work until yields procedures are lowered, because it has to both run a blocking block and produce a value — the two-call form does that explicitly.