mirror of https://github.com/kdl-org/kdl.git
145 lines
3.4 KiB
Markdown
145 lines
3.4 KiB
Markdown
# kdl - Kat's Document Language
|
|
|
|
kdl is a document language, mostly based on [SDLang](https://sdlang.org), with
|
|
xml-like semantics that looks like you're invoking a bunch of CLI commands!
|
|
|
|
It's meant to be used both as a serialization format and a configuration
|
|
language, and is relatively light on syntax compared to XML.
|
|
|
|
## Intro
|
|
|
|
Most of the syntax is basically the same as SDLang:
|
|
|
|
```kdl
|
|
// This is a node with a single string value
|
|
title "Hello, World"
|
|
|
|
// Multiple values are supported, too
|
|
bookmarks 12 15 188 1234
|
|
|
|
// Nodes can have attributes
|
|
author "Alex Monad" email="alex@example.com" active=true
|
|
|
|
// Nodes can be arbitrarily nested
|
|
contents {
|
|
section "First section" {
|
|
paragraph "This is the first paragraph"
|
|
paragraph "This is the second paragraph"
|
|
}
|
|
}
|
|
|
|
// Nodes can be separated into multiple lines
|
|
title \
|
|
"Some title"
|
|
|
|
// Comment formats:
|
|
|
|
// C++ style
|
|
|
|
/*
|
|
C style multiline
|
|
*/
|
|
|
|
tag /*foo=true*/ bar=false
|
|
```
|
|
|
|
But kdl changes a few details:
|
|
|
|
```kdl
|
|
// Files must be utf8 encoded!
|
|
smile "😁"
|
|
|
|
// Instead of anonymous nodes, nodes and properties can be wrapped
|
|
// in "" for arbitrary node names.
|
|
"!@#$@$%Q#$%~@!40" "1.2.3" "!!!!!"=true
|
|
|
|
// The following is a legal bare identifier:
|
|
foo123~!@#$%^&*.:'|<>/?+ "weeee"
|
|
|
|
// kdl specifically allows properties and values to be
|
|
// interspersed with each other, much like CLI commands.
|
|
foo bar=true "baz" quux=false 1 2 3
|
|
|
|
// strings can be multiline as-is, without a different syntax.
|
|
string "my
|
|
multiline
|
|
value"
|
|
|
|
// raw/unescaped strings use the "r" prefix on string literals and
|
|
// otherwise behave the same, including multiline support.
|
|
raw r"C:\Users\kdl"
|
|
|
|
// You can add any number of # after the r and the last " to
|
|
// disambiguate literal " characters.
|
|
other-raw r#"hello"world"#
|
|
|
|
// There is a single decimal number type, much like JSON's.
|
|
num 1.234e-42
|
|
|
|
// Numbers can have underscores to help readability:
|
|
bignum 1_000_000
|
|
|
|
// There is additional support for literal hexadecimal, octal, and binary input.
|
|
my-hex 0xdeadbeef
|
|
my-octal 0o755
|
|
my-binary 0b1010_1101
|
|
```
|
|
|
|
The following SDLang features are removed altogether:
|
|
|
|
* "Anonymous" nodes
|
|
* Binary data literals
|
|
* Date/time formats
|
|
* `on` and `off` booleans
|
|
* Backtick strings
|
|
* Semicolons
|
|
* Namespaces with `:`
|
|
* Shell style (`#`) and Lua-style (`--`) comments
|
|
* Distinction between 32/64/128-bit numbers. There's just numbers.
|
|
|
|
## Design and Discussion
|
|
|
|
kdl is still extremely new, and discussion about the format should happen over
|
|
on the [discussions page](https://github.com/zkat/kdl/discussions). Feel free
|
|
to jump in and give us your 2 cents!
|
|
|
|
## Grammar
|
|
|
|
```
|
|
document := linespace* node (ws* linespace* document)
|
|
|
|
// TODO: this is broken, please fix it
|
|
node := identifier ws+ (prop | value)*
|
|
(ws+ escline* ws* (prop | value))*
|
|
ws* ('{' linespace* document linespace* '}')?
|
|
newline
|
|
|
|
identifier := [a-zA-Z] [a-zA-Z0-9~!@#$%&*-_+.:?/|]* | string
|
|
|
|
prop := identifier '=' value
|
|
|
|
value := string | raw-string | number | boolean | 'null'
|
|
|
|
string := '"' (TODO LOL) '"'
|
|
|
|
raw-string := 'r' '#'*n '"' (TODO LOL) '"' '#'*n
|
|
|
|
number := decimal | hex | octal | binary
|
|
|
|
decimal := TODO LOL
|
|
|
|
hex := '0x' [0-9a-fA-F] [0-9a-fA-F_]*
|
|
|
|
octal := '0o' [0-7] [0-7_]*
|
|
|
|
binary := '0b' ('0' | '1') ('0' | '1' | '_')*
|
|
|
|
boolean := 'true' | 'false'
|
|
|
|
escline := '\' newline
|
|
|
|
linespace := newline | ws
|
|
|
|
newline := (CR LF) | LF
|
|
```
|