Method execute

graphlite/src/functions/string_functions.rs:44–66

(&self, context: &FunctionContext)

    }

    fn execute(&self, context: &FunctionContext) -> FunctionResult<Value> {
        // Get the actual value argument (not column name)
        let value = context.get_argument(0)?;

        if value.is_null() {
            return Ok(Value::Null);
        }

        // Handle both strings and numbers - convert to string first
        let string_val = if let Some(s) = value.as_string() {
            s.to_string()
        } else if let Some(n) = value.as_number() {
            n.to_string()
        } else {
            // Try to convert other types to string representation
            match value {
                Value::Boolean(b) => b.to_string(),
                _ => return Ok(Value::Null), // Return null for non-convertible types
            }
        };

        Ok(Value::String(string_val.to_uppercase()))
    }

    fn return_type(&self) -> &str {
        "String"