From fe1035633a1a17febbec6d42d53ab8c9afeddfc1 Mon Sep 17 00:00:00 2001 From: Přemysl Janouch Date: Tue, 17 Apr 2018 00:50:46 +0200 Subject: Describe syntax of advanced configuration w/ PEG --- liberty.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/liberty.c b/liberty.c index ef6a398..51b7058 100644 --- a/liberty.c +++ b/liberty.c @@ -4337,6 +4337,32 @@ socket_io_try_write (int socket_fd, struct str *wb) // This is a more powerful configuration format, adding key-value maps and // simplifying item validation and dynamic handling of changes. All strings // must be encoded in UTF-8. +// +// The syntax is roughly described by the following parsing expression grammar: +// +// config = entries eof # as if there were implicit curly braces around +// entries = (newline* pair)* newline* +// pair = key newline* lws '=' newline* value (&endobj / newline / eof) +// key = string / !null !boolean lws [A-Za-z_][0-9A-Za-z_]* +// value = object / string / integer / null / boolean +// +// object = lws '{' entries endobj +// endobj = lws '}' +// +// string = lws '"' ('\\' escape / ![\\"] char)* '"' +// char = [\0-\177] # or any Unicode codepoint in the UTF-8 encoding +// escape = [\\"abfnrtv] / [xX][0-9A-Fa-f][0-9A-Fa-f]? / [0-7][0-7]?[0-7]? +// +// integer = lws '-'? [0-9]+ # whatever strtoll() accepts on your system +// null = lws 'null' +// boolean = lws 'yes' / lws 'YES' / lws 'no' / lws 'NO' +// / lws 'on' / lws 'ON' / lws 'off' / lws 'OFF' +// / lws 'true' / lws 'TRUE' / lws 'false' / lws 'FALSE' +// +// newline = lws comment? '\n' +// eof = lws comment? !. +// lws = [ \t\r]* # linear whitespace (plus CR as it is insignificant) +// comment = '#' (!'\n' .)* enum config_item_type { -- cgit v1.2.3-70-g09d2