boon4681/cardboard

cardboard

Cardboard is a lexer language for Minecraft syntax.

@bind(brigadier:string)
lexer String {
    lexer Quoted {
        (
            text = "[\\\']+";
            escape = '\\\\[tbrn\'\"\\\\]';
        )*
        close = "'" -> pop;
    }

    lexer DoubleQuoted {
        (
            text = "[\\\"]+";
            escape = '\\\\[tbrn\'\"\\\\]';
        )*
        double_quoted_close = '"' -> pop;
    }

    @if("'"){
        open = "'" -> push(Quoted);
    } -> end

    double_quoted_open = '"' -> push(DoubleQuoted);
}

Grammar

Keywords

keywords cannot be used as identifiers:

• lexer
• @bind
• @if

Identifier

syntax in regex:

[_\w]\[_\w\d]*

used as lexer name and token name

Example:

hello

Cardboard meta

syntax in regex:

\@(?:[_\w][_\w\d]*)(?:\.(?:[_\w][_\w\d]*))*

Example:

@registries.block

Strings

qouted string syntax:

' .* '

double qouted string syntax:

" .* "

Example:

"hi this is cardboard"

'cardboard built with pulpboard'

Token

syntax:

name = (strings, lexer name, cardboard meta, group, wrapper) ;

Example

hi = "HI" hello @registries.block

Group

read once syntax:

( token )

read once or repeat syntax:

( token )+

read once or null syntax:

( token )?

read null or repeat syntax:

( token )*

lexer will read items in a group and stoped when find the available index

Wrapper

read once syntax:

[ token ]

read once or repeat syntax:

[ token ]+

read once or null syntax:

[ token ]?

read null or repeat syntax:

[ token ]*

lexer will read items in a wrapper and stoped when reached the last index

If statement

Not ended syntax:

@if ( strings as a condition ) { if-context }

Ended syntax:

@if ( strings as a condition ) { if-context } -> end

Ended means cardboard will not continue on next token in lexer

If Context

syntax:

token | if-statement | group | wrapper

Lexer Declaration

syntax:

lexer name { lexer-context }

Lexer Context

syntax:

lexer | token | if-statement | group | wrapper