Method invoke

lib/dsc-lib/src/functions/substring.rs:33–97

(&self, args: &[Value], _context: &Context)

    }

    fn invoke(&self, args: &[Value], _context: &Context) -> Result<Value, DscError> {
        debug!("{}", t!("functions.substring.invoked"));

        let string_to_parse = args[0].as_str().unwrap();
        let start_index_value = args[1].as_i64().unwrap();

        if start_index_value < 0 {
            return Err(DscError::FunctionArg(
                "substring".to_string(),
                t!("functions.substring.startIndexNegative").to_string(),
            ));
        }

        let start_index = usize::try_from(start_index_value).map_err(|_| {
            DscError::FunctionArg(
                "substring".to_string(),
                t!("functions.substring.startIndexValueTooLarge").to_string(),
            )
        })?;
        let string_length = string_to_parse.chars().count();

        if start_index > string_length {
            return Err(DscError::FunctionArg(
                "substring".to_string(),
                t!("functions.substring.startIndexTooLarge").to_string(),
            ));
        }

        let length = if args.len() == 2 {
            string_length - start_index
        } else {
            let length_value = args[2].as_i64().unwrap();

            if length_value < 0 {
                return Err(DscError::FunctionArg(
                    "substring".to_string(),
                    t!("functions.substring.lengthNegative").to_string(),
                ));
            }

            let length = usize::try_from(length_value).map_err(|_| {
                DscError::FunctionArg(
                    "substring".to_string(),
                    t!("functions.substring.lengthValueTooLarge").to_string(),
                )
            })?;

            if start_index + length > string_length {
                return Err(DscError::FunctionArg(
                    "substring".to_string(),
                    t!("functions.substring.lengthTooLarge").to_string(),
                ));
            }

            length
        };

        let result: String = string_to_parse