ini.pest

ini = { SOI ~ bom? ~ (blank | pair | comment)* ~ section* }

// lines
blank = _{ "" ~ NEWLINE }
pair = { key ~ "=" ~ value ~ eol }
comment = ${ indicator ~ comment_value ~ eol }
comment_value = ${ char* }

// sections
section = { header ~ eol ~ body }
body = { (blank | pair | comment)* }

// tokens
// a name must end with a closing bracket followed by optional whitespace and EOL
header = ${ "[" ~ header_text ~ "]" }
header_text = @{ (!header_end ~ char)+ }
header_end = !{ "]" ~ eol }
// a key may not begin with an opening bracket and may not contain an equal sign
key = @{ (!("=" | "[") ~ char) ~ (!key_end ~ char)* }
key_end = @{ (WHITESPACE* ~ "=") } // Trim key's trailing whitespace
value = @{ (!value_end ~ char)* }
value_end = @{ WHITESPACE+ ~ eol } // Trim value's trailing whitespace

// atomic primitives
bom = _{ "\u{feff}" }
indicator = { "#" | ";" }
char = { !eol ~ ANY }
eol = _{ NEWLINE | EOI }

WHITESPACE = _{ " " | "\t" }