XCFG

Custom configuration format.

Config format

section {
    field: value,
    subsection [attribute=value] {
        field: value
        list: {element1, element2, element3}
    }
    another_subsection [attribute1, attribute2] {
        field: "Some string",
        empty_subsubsection {}
    }
}

API

Base type for config is xcfg::Value.
Values can store an object (key-value pair) or a string value.
Values can also be empty or contain an expression.

xcfg::Value::string() - returns string value of a field.
xcfg::Value::attrs() - returns attributes of a section as a map of string and string.
xcfg::Value::items() - returns fields and subsections as map of string and Value.
xcfg::Value::get(const std::string& path) - returns nested value, e.g. root.get("section.subsection.field"), which itself will return xcfg::Value.
xcfg::Value::isString() - returns true if value is a string.
xcfg::Value::isObject() - returns true if value is an object.

String can be parsed into a xcfg::Value using xcfg::parse(const std::string& src).
As was mentioned above - a value can also be an expression.
Expressions allow users to include other files, define constants and use them later on.
Expressions aren't processed automatically, to process all expressions in a value xcfg::process(Value& root, Value& value, Env& env) is used.
xcfg::Env contains include paths and defines.

Example of expressions:

${include another_config_file.xcfg}
${define CONSTANT 42}
section {
    subsection1 {
        value: ${CONSTANT}
    }
    subsection2 {
        ${insert section.subsection1}
    }
}

include - takes 1 parameter - path to file, which will be parsed and inserted in place of include directive.
define - takes 2 parameters - name and value of a constant.
insert - takes 1 parameter - comma separated path of an element relative to root, this element will be inserted in place.

Any other words encased in ${} will be treated as a constant name, and will be inserted in place.

How to install

Prerequisites:

• Unix like system (WSL works too)
• gcc or clang with c++17 support
• cmake

To build:

• cmake -S . -B build
• cmake --build build