gyrus-dev/frosty/snowflake-create-function

Before writing a CREATE FUNCTION statement:

1. Read references/parameters.md to review all available parameters and their defaults.
2. For each parameter, decide whether the user's request implies a non-default value.
3. Include only the parameters that differ from the default or that the user explicitly requested.
4. Never use CREATE OR REPLACE — always use CREATE FUNCTION IF NOT EXISTS where supported.
5. Select the correct LANGUAGE clause (SQL, JAVASCRIPT, PYTHON, JAVA, SCALA) based on the user's intent; when the language is ambiguous, prefer SQL for simple transformations and Python for complex logic.
6. For tabular UDFs use RETURNS TABLE (col_name col_data_type [, ...]) instead of a scalar return type.
7. Python UDFs require an explicit RUNTIME_VERSION; Java and Scala UDFs require a HANDLER pointing to the class/method.
8. Place optional arguments (those with DEFAULT values) after all required arguments in the signature.
9. Use RETURNS NULL ON NULL INPUT (STRICT) when the function has no meaningful behavior on NULLs, to avoid unnecessary invocations.