README.md

SECL

SECL is a S-Expression based configuration language, drawing inspiration and syntax from JSON and YAML.

It's main goal is to provide a configuration format that is easy to read and write with little overhead while being simple and understandable in it's syntax and parsing.

list-entry

key: (
    another-list-entry
    key: "Hello World!"
    explicit: "UTF-8 support: 💩"
    
    other-features: (
        "arbitrary precision decimals": 29312345320423531230497123416079652.234234234
        "and integers": 343287640123745610476123012734613047236402374620376234023746
        "scientific notation": 9.0*10^22
        "multi-line strings": "
            HELLO WORLD!"
        "omit quotation around simple strings": Hello-Again
        "load other files from subfolders": !(loadd "folder" ".conf")
        "empty maps": empty
        
        "random values": (
            randstr128
            maybe
        )
        
        "mix lists and maps, they are the same in SECL"
    )
)

Project Status

SECL is considered in Version 0.9

Most features are now part of the authorative implementation in this repository.

Missing features:

• Hex, Octal and Binary Notation (0x1F, 0o777, 0b110101)
• Float E and Scientific Notation (2.3e18 or 2.3*10^18)
• Function Execution (Functions are recognized but not executed)

Introduction

Strings

Strings that do not contain any whitespace (as recognized by UTF8) and do not start with a digit or contain reserved character can omit quotation marks;

HelloWorld

Reserved characters: "!@:()

If any of the reserved characters is present, the string must be wrapped with quotation marks. Additionally, if the string equals a keyword or function name, it must be wrapped with quotation marks too. (ex. "false" or "empty" or "randstr256")

"Hello World"

Strings are multi-line by default, if you want to trim leading whitespace from each line and the beginning of the string, prepend a @ symbol.

@"
Hello 
 World"
 
// equivalent to

"Hello
World"

The special values randstr and randstr32 to randstr256 allow the usage of random strings in the config. This can be useful for security purposes.

Comments

Single-line comments are started using //, # or ;

Multiline Comments are wrapped in standard C multline comment slashes. /* comment */

Numbers

Numbers are divided into integers and floats with no predefined precision.

Integers must be noted as digits in full, leading digits may be used. 0x, 0o and 0b are used for hexadecimal, octal and binary notation respectively.

Floats can be noted in normal decimal notation, exponent notation or scientific notation:

0.001
1e-3
1.0*10^-3

Keys and Lists and Maps

A string with an appended : is a map-key. These can be virtually used everywhere except after another map key.

The item after a map key is added to the current Map-List as a Map item. If an item has no key, it is added to the current Map-List as a List item.

The top level of a SECL file is considered a Map-List. A new Map-List is started by a parenthesis and must be terminated by one:

outmost-map

(
    new-map-here
)

The keywords empty and nothing are equivalent to () for readability

Internally, there is no difference between an list (also known as array) and a map, both use the same datatype and list elements can be mixed into dictionary entries.

Lists must be sorted exactly in the order that is observed in the input file. The list resulting from (a b c) must have a as first element and c as last.

Booleans

There are three categories of keywords for booleans:

• true
• false
• maybe

The true category contains true, yes, on and allow

The false category contains false, no, off and deny

The maybe category contains maybe. This keywords randomly evaluates to either true or false with a 50.1% chance of being true.