Control Flow & Loops

Prady provides expressive control structures for branching, looping, and pattern matching.

Conditional Branching: if and else

Conditionals in Prady require boolean expressions. The parentheses around conditions are optional, but braces {} around blocks are mandatory:

let status = 200;

if status >= 200 && status < 300 {
    print("Request successful!");
} else if status == 404 {
    print("Resource not found.");
} else {
    print("Unexpected error code: " + status);
}

Loops

Prady supports three loop constructs: while, traditional for, and collection iteration with foreach.

while Loops

The while loop runs as long as a condition evaluates to true:

let mut count = 3;
while count > 0 {
    print("Countdown: " + count);
    count = count - 1;
}
print("Liftoff!");

for Loops

Traditional three-clause for loops are ideal for indexed counter iterations:

for let mut i = 0; i < 5; i = i + 1 {
    print("Iteration index: " + i);
}

foreach Loops

To iterate over elements in arrays, lists, or sets, use foreach:

let items = ["Engine", "Parser", "AST", "Emitter"];

foreach item in items {
    print("Processing compiler phase: " + item);
}

Break & Continue

You can control loop iteration using break to exit early or continue to jump to the next cycle:

let numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

foreach n in numbers {
    if n % 2 != 0 {
        continue; // Skip odd numbers
    }
    if n > 6 {
        break; // Stop iteration when exceeding 6
    }
    print("Even number: " + n);
}

switch Statements

The switch statement in Prady provides clean, multi-way branch dispatching. In Prady, cases do not silently fall through, eliminating common C-style bugs:

let command = "build";

switch command {
    case "run":
        print("Compiling and executing immediately...");

    case "build":
        print("Emitting optimized standalone LLVM binary...");

    case "check":
        print("Verifying types and architecture contracts...");

    default:
        print("Unknown command: " + command);
}

Next Step: Functions & Lambdas

Proceed to Functions & Lambdas to learn how functions, closures, and higher-order collection pipelines work.