P5LIVE sandbox and strudel regions must use matched open/close comment delimiters at top level, not inside functions

P5LIVE uses paired comment delimiters to demarcate embedded Hydra (// sandbox … // sandbox) and Strudel (// strudel … // strudel) regions. An unmatched or mistyped delimiter causes one of two failures: the embedded code never evaluates (silent failure), or the content is swept into the p5 recompile, triggering hardCompiles on every Hydra keystroke — which defeats the purpose of the sandbox. Regions must be placed at the top level of the file, not nested inside setup() or draw(). This pairing rule is structural: the parser treats everything between matching delimiters as belonging to a different runtime.

Examples

Correct: // sandbox\nosc(40,0.1).out()\n// sandbox at file top level. Wrong: placing the sandbox block inside function draw() {}.

Assessment

Given a P5LIVE file that triggers a full hardCompile every time a Hydra parameter is tweaked, diagnose the most likely structural cause and show the fix.