rhaj/rhai_engine/rhaibook/engine/disable-looping.md

Disable Looping

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For certain scripts, especially those in embedded usage for straight calculations, or where Rhai script [AST]'s are eventually transcribed into some other instruction set, looping may be undesirable as it may not be supported by the application itself.

Rhai looping constructs include the [while], [loop], [do] and [for] statements.

Although it is possible to disable these keywords via [Engine::disable_symbol][disable keywords and operators], it is simpler to disable all looping via [Engine::set_allow_looping][options].

use rhai::Engine;

let mut engine = Engine::new();

// Disable looping
engine.set_allow_looping(false);

// The following all return parse errors.

engine.compile("while x == y { x += 1; }")?;

engine.compile(r#"loop { print("hello world!"); }"#)?;

engine.compile("do { x += 1; } until x > 10;")?;

engine.compile("for n in 0..10 { print(n); }")?;