# This is the Pegex grammar for Pegex grammars! %grammar pegex %version 0.2.0 %include pegex-atoms grammar: meta-section rule-section ( doc-ending | ERROR-rule-definition ) meta-section: ( meta-definition | + | ERROR-meta-definition )* rule-section: ( rule-definition | + )* meta-definition: / '%' meta-name BLANK+ meta-value / rule-definition: rule-start rule-group ending rule-start: / ( rule-name ) BLANK* ':' -/ rule-group: any-group any-group: /- '|'? -/ all-group ( /- '|' -/ all-group )* all-group: rule-part (- rule-part)* rule-part: (rule-item)1-2 % /+ ( '%'{1,2} ) +/ rule-item: | bracketed-group | whitespace-token | rule-reference | quoted-regex | regular-expression | error-message rule-reference: / ( rule-modifier? ) # [=!.-+] (: # foo | ( rule-name ) | (: '<' ( rule-name ) '>' ) ) ( rule-quantifier? ) # [?*+] 2+ 2-3 (! BLANK* ':' ) # Avoid parsing 'foo:' / # as a rule reference. quoted-regex: / TICK ( [^ TICK ]* ) TICK / regular-expression: /( group-modifier? )/ '/' whitespace-start? ( | whitespace-must | whitespace-maybe | quoted-regex | regex-rule-reference | + | regex-raw )* '/' whitespace-start: / ([ PLUS DASH]) (! [ DASH TILDE ]) / whitespace-must: /+ (: PLUS | DASH DASH ) (= [ SPACE SLASH CR NL ]) / whitespace-maybe: /- DASH (= [ SPACE SLASH CR NL ]) / regex-rule-reference: / (: + ( rule-name ) | (: '<' ( rule-name ) '>' ) ) (! BLANK* ':' ) / regex-raw: / ( '(?'? '<' | (?:[^ WS SLASH TICK LANGLE ])+ ) / bracketed-group: / ( group-modifier? ) '(' -/ rule-group /- ')' ( rule-quantifier? ) / whitespace-token: / ( (: PLUS | DASH | DASH DASH | TILDE | TILDE TILDE ) ) (= + )/ error-message: / '`' ( [^ '`' DOS ]* ) '`' / rule-modifier: / [ BANG EQUAL PLUS DASH DOT ] / group-modifier: / [ DASH DOT ] / rule-quantifier: / (: [ STAR PLUS QMARK ] | DIGIT+ (: DASH DIGIT+ | PLUS)? ) / meta-name: / ( 'grammar' | 'extends' | 'include' | 'version' ) / meta-value: / BLANK* ( [^ SEMI BREAK ]*? ) BLANK* ending / rule_name: / (: ALPHA ALNUM* (:[ DASH UNDER ] ALNUM+)* | DASH+ | UNDER+ ) (= [^ WORD DASH ]) / ending: / - (: BREAK - SEMI? - | comment - SEMI? - | SEMI - | EOS ) / ws: / (: WS | comment ) / comment: / '#' ANY* (: BREAK | EOS ) / ### # Pegex common error recognition and reporting: ### doc-ending: /- EOS / illegal-non-modifier-char: / [^ WORD LPAREN RPAREN LANGLE SLASH TILDE PIPE GRAVE WS ] / illegal-non-quantifier-char: / [^ WORD LPAREN RPAREN LANGLE SLASH TILDE PIPE GRAVE WS STAR PLUS QMARK BANG EQUAL PLUS DASH DOT COLON SEMI ] / ERROR-meta-definition: /(= PERCENT WORD+ )/ `Illegal meta rule` # Much of this is essentially a duplicate of the above rules, except with added # error checking ERROR-rule-definition: ERROR-rule-start ERROR-rule-group ( ending | `Rule ending syntax error` ) ERROR-rule-group: ERROR-any-group | ERROR-all-group ERROR-all-group: ERROR-rule-part+ % - ERROR-any-group: (ERROR-all-group)2+ % /- PIPE -/ ERROR-rule-part: (ERROR-rule-item)1-2 % /+ ( PERCENT{1,2} ) +/ ERROR-rule-start: / ( rule-name ) BLANK* COLON -/ | `Rule header syntax error` ERROR-rule-item: rule-item | ERROR-rule-reference | ERROR-regular-expression | ERROR-bracketed-group | ERROR-error-message # Errors - rule-reference ERROR-rule-reference: /(= rule-modifier? LANGLE rule-name (! RANGLE ) )/ `Missing > in rule reference` | /(= rule-modifier? rule-name RANGLE )/ `Missing < in rule reference` | /(= rule-modifier? (: rule-name | LANGLE rule-name RANGLE ) illegal-non-quantifier-char )/ `Illegal character in rule quantifier` | /(= rule-modifier? rule-name DASH )/ `Unprotected rule name with numeric quantifier; please use #-# syntax!` | !rule-modifier /(= illegal-non-modifier-char (: rule-name | LANGLE rule-name RANGLE ) rule-quantifier? # [?*+] 2+ 2-3 (! BLANK* COLON ) # Avoid parsing 'foo:' )/ # as a rule reference. `Illegal rule modifier (must be [=!.-+]?)` # Errors - regular-expression ERROR-regular-expression: /(= SLASH ( [^ SLASH ]* ) doc-ending )/ `Runaway regular expression; no ending slash at EOF` # Errors - bracketed-group ERROR-bracketed-group: /(! group-modifier) (= illegal-non-modifier-char LPAREN )/ `Illegal group rule modifier (can only use .)` | / ( group-modifier? ) LPAREN -/ rule-group ( =doc-ending `Runaway rule group; no ending parens at EOF` | / (= - RPAREN illegal-non-quantifier-char ) / `Illegal character in group rule quantifier` ) # Errors - error-message ERROR-error-message: /(= GRAVE [^ GRAVE DOS ]* [ DOS ] [^ GRAVE ]* GRAVE )/ `Multi-line error messages not allowed!` | /(= GRAVE [^ GRAVE ]* doc-ending )/ `Runaway error message; no ending grave at EOF` # Errors - separation ERROR-separation: /(= - PERCENT{3} )/ `Leading separator form (BOK) no longer supported` | /(= - PERCENT{1,2} [^ WS ] )/ `Illegal characters in separator indicator` # vim: set lisp: