Method execute

graphlite/src/functions/timezone_functions.rs:174–209

(&self, context: &FunctionContext)

    }

    fn execute(&self, context: &FunctionContext) -> FunctionResult<Value> {
        if context.arguments.len() != 2 {
            return Err(FunctionError::InvalidArgumentCount {
                expected: 2,
                actual: context.arguments.len(),
            });
        }

        let datetime_arg = &context.arguments[0];
        let timezone_arg = &context.arguments[1];

        // Extract timezone string
        let tz_str =
            timezone_arg
                .as_string()
                .ok_or_else(|| FunctionError::InvalidArgumentType {
                    message: "Timezone must be a string".to_string(),
                })?;

        // Parse timezone
        let timezone = parse_timezone(tz_str)
            .map_err(|e| FunctionError::InvalidArgumentType { message: e })?;

        // Convert datetime to UTC first if needed
        let utc_dt = match datetime_arg.as_datetime_utc() {
            Some(dt) => dt,
            None => {
                return Err(FunctionError::InvalidArgumentType {
                    message: "First argument must be a datetime".to_string(),
                })
            }
        };

        // Convert to target timezone
        Ok(timezone.convert_from_utc(&utc_dt))
    }

    fn graph_context_required(&self) -> bool {
        false // Timezone functions are pure scalar functions