SCGSM Rust Edition v0.2.1

Developed by Spencer Smith (spenny@geniuspiece.com)

Last updated 26 August 2020

SCGSM is a very simple specification for saving and managing game data.

Usage

This library is available through crates.io! To add it to your project, simply add the following line underneath the dependencies tag in your Cargo.toml file:

scgsm = "0.2.1"

Syntax

The structure of an SCGSM file (.scgs) is as follows:

FLAG_A|1
FLAG_B|2
FLAG_C|3

The pipe operator (|) takes two parameters, a flag key on the left, and a flag value on the right. Flag values can be any type, and they will be stored as a String variable in the actual flag object, meaning that it's up to you to typecast values when applying them to variables in the Rust code.

There must be only one key/value pair per line, and there must be no spaces between the parameters and pipe.

Changes from previous versions

August 26, 2020

• Added new cast_value function to easily parse flag values and store in variables.

August 25, 2020

• Project renamed to avoid conflicts with another SCFS.

• In the original C++ implementation of SCGSM, there was a function called sc::GSM::parse() that would read the .scgs file line by line and split it into separate strings. This function was unnecessary in the Rust Edition and all that functionality has been condensed into the SCGSM::load_flags() function instead.

• Originally .scgs files would end with the line "ENDFLAGS", however this was decided to be redundant and thus removed from this version of the specification.

Glossary

pub struct Flag - Structure which defines all of the in-game flags. Has two member variables, pub key: String and pub value: String.

pub fn Flag::init(k: &str, v: &str) -> Flag - Function that creates a new Flag with key k and value v.

pub struct SCGSM - Structure which defines objects and functions for saving, loading, and managing game data. Has one member variable, pub flags: Vec<Flag>, which stores all of the flags in memory.

pub fn SCGSM::init() -> SCGSM - Function that creates a new SCGSM variable with an empty vector.

pub fn SCGSM::add_flag(&mut self, k: &str, v: &str) - This function creates a new Flag object f and then calls self.flags.push(f).

pub fn SCGSM::cast_value<T>(&mut self, i: usize) -> T - This function allows you to easily parse flag values to different types for saving in variables. The i parameter is the index of the Flag object in the flags vector, which is indexed in the order that flags are written in the .scgs script, starting from 0.

pub fn SCGSM::load_flags(&mut self, sf: &str) - This function reads the output of file sf line by line and uses a string splitting algorithm to create new flags for each line and add them to the flags vector.

pub fn SCGSM::save_flags(&mut self, sf: &str) -> std::io::Result<()> - This function writes the output of SCGSM::viewFlags() to file sf.

pub fn SCGSM::update_flag(&mut self, k: &str, v: &str) - This function modifies the value of Flag objects by iterating through the flags list to find the key that matches k and changing the value of that flag to v. If the flag key cannot be found, the function will fail.

pub fn SCGSM::view_flags(&mut self) -> String - This function returns the entire flags list as a String object.