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ADP-005 — Parser Recursion Limits

• Status: Approved & Implemented
• Deciders: Poppy Team
• Phase: Wave 1

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Context

Recursive-descent parsers can suffer from stack overflows when encountering deeply nested syntactic inputs (such as ((((...10,000 parentheses...))))), crashing the host process with unhandled panics.

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Decisions Taken

1. The Aipo parser tracks an explicit recursion depth counter.
2. The default threshold is fixed at 256 nesting levels.
3. Exceeding this boundary aborts compilation gracefully with diagnostic AIPO_SYN_RECURSION_LIMIT_EXCEEDED without panicking in Rust.