grammar ChitChat::Grammar is PCT::Grammar;

token TOP { <ws> [ | <exprs> | <methods> | '!' ]+ <ws> [ $ || <panic: 'Syntax error'> ] {*} }

token whitespace { \h | \v | <comment> }

token ws { <whitespace>* }

token comment { '"' <-["]>* '"' }

rule methods { '!' <id> 'class'? 'methodsFor:' <string> '!' [<method> '!']? '!' }

rule method { <message> <pragma>? <temps>? <exprs> }

token message { <id> | <binsel> <.ws> <id> | [<keysel> <.ws> <id>]+ }

token pragma { '<' <keymsg> '>' }

rule temps { '|' [<id> ]* '|' }

token unit { | <id> {*} #= id | <literal> {*} #= literal | <block> {*} #= block | <arrayconstructor> {*} #= arrayconstructor | '(' <expr> ')' {*} #= expr }

rule unaryexpr { <unit> [<!keysel><id> ]+ {*} }

token primary { <!unaryexpr> <unit> {*} | <unaryexpr> {*} }

rule exprs { [ | <expr> [ '.' <expr>]* ['.' '^' <expr>]? '.'? | '^' <expr> '.'? ] {*} }

rule expr { [<id> [':='|'_']]* <expr2> {*} }

rule expr2 {[ <msgexpr> [ ';' <cascade> ]* | <primary> ] {*} }

token msgexpr { | <keyexpr> {*} #= keyexpr | <binexpr> {*} #= binexpr | <unaryexpr> {*} #= unaryexpr }

token cascade { <id> | <binmsg> | <keymsg> }

rule binexpr { <primary> <binmsg> [<binmsg> ]* {*} }

rule binmsg { <binsel> <primary> }

token binsel { <binchar>**{1..2} }

rule keyexpr { <keyexpr2> <keymsg> {*} }

token keyexpr2 { <!binexpr> <primary> {*} | <binexpr> {*} }

rule keymsg { [<keysel> <keyexpr2> ]+ {*} }

token keysel { <id> ':' }

rule block { '[' [[':' <id>]* '|']? <temps>? <exprs> ']' }

token arrayconstructor { '{' <exprs> '}' }

token literal { | <number> {*} #= number | <string> {*} #= string | <charconst> {*} #= charconst | <symconst> {*} #= symconst | <arrayconst> {*} #= arrayconst | <binding> {*} #= binding | <eval> {*} #= eval }

token arrayconst { '#' <array> | '#' <bytearray> }

token bytearray { '[' <number>* ']' }

rule array { '(' [ <literal> | <array> | <bytearray> | <arraysym> ]* ')' }

token number { [<.digit>+ 'r']? '-'? <.alnum>+ ['.' <.alnum>+]? [<exp> '-'? <dig>+]? }

token string { \' $<text>:=<-[']>* \' {*} }

token charconst { '$' . }

token symconst { '#'<symbol> | '#'<string> }

token arraysym { [<id> | ':']* }

token exp { <[deqs]> }

token binding { '#{' [<id> '.']* <id> '}' }

token symbol { <id> | <binsel> | <keysel>**{1..2} }

rule eval { '##(' <temps>? <exprs> ')' }

token id { <.alpha> [ <.alpha> | <.digit> ]* }

token binchar { <[+\-*/~,<>=&´?\\%]> }