pep508.lark

start: _requirement

_requirement: _full_name (_MARKER_SEPARATOR marker_spec)?
_full_name: NAME _extras? (version_specification | _url)?
_extras: _L_BRACKET _extra? _R_BRACKET
_extra: EXTRA (_COMMA EXTRA)*
version_specification: (_version_many | _L_PAREN _version_many _R_PAREN)
_version_many: _single_version (_COMMA _single_version)*
_single_version: LEGACY_VERSION_CONSTRAINT
_url: _AT URI
marker_spec: marker

NAME: /[a-zA-Z][a-zA-Z0-9-_.]*/
FULL_NAME: NAME
EXTRA: NAME
VERSION_CONSTRAINT: /(~=|==|!=|<=|>=|<|>|===)((?:(?<====)\s*[^\s]*)|(?:(?<===|!=)\s*v?(?:[0-9]+!)?[0-9]+(?:\.[0-9]+)*(?:[-_.]?(a|b|c|rc|alpha|beta|pre|preview)[-_.]?[0-9]*)?(?:(?:-[0-9]+)|(?:[-_.]?(post|rev|r)[-_.]?[0-9]*))?(?:(?:[-_.]?dev[-_.]?[0-9]*)?(?:\+[a-z0-9]+(?:[-_.][a-z0-9]+)*)? # local|\.\*)?)|(?:(?<=~=)\s*v?(?:[0-9]+!)?[0-9]+(?:\.[0-9]+)+(?:[-_.]?(a|b|c|rc|alpha|beta|pre|preview)[-_.]?[0-9]*)?(?:(?:-[0-9]+)|(?:[-_.]?(post|rev|r)[-_.]?[0-9]*))?(?:[-_.]?dev[-_.]?[0-9]*)?)|(?:(?<!==|!=|~=)\s*v?(?:[0-9]+!)?[0-9]+(?:\.[0-9]+)*(?:[-_.]?(a|b|c|rc|alpha|beta|pre|preview)[-_.]?[0-9]*)?(?:(?:-[0-9]+)|(?:[-_.]?(post|rev|r)[-_.]?[0-9]*))?(?:[-_.]?dev[-_.]?[0-9]*)?))/i
LEGACY_VERSION_CONSTRAINT: /(~=|==|!=|<=|>=|<|>)\s*[^,;\s)]*/i
URI: /[^ ]+/
_MARKER_SEPARATOR: ";"
_L_PAREN: "("
_R_PAREN: ")"
_L_BRACKET: "["
_R_BRACKET: "]"
_COMMA: ","
_AT: "@"

%import .markers.marker
%import common.WS_INLINE
%ignore WS_INLINE