ÿØÿà JFIF    ÿÛ „ !.%+&8&+/1555$;@;4?.451 4,$,44444444444414444444444444444444444444444444444444ÿÀ  á á" ÿÄ     ÿÄ ?    !1AQaq"2‘¡±ÁðBRbrÑá#‚’¢²3S CñÿÄ   ÿÄ !    !1QAa‘2ÿÚ   ? 5˜Z¯V¦cø)›t/? z¨±>Õ5€¶‹Á¤·¼z¼Ü¬+ñ®v¤¨_ˆR­BFn©—˜ý®ç̝P8gýt·ÉSTŦˆìät?þé¼íìN/Þa)ì–í6ô… Ï¿øÃj´¿KÇü]ÿ ªô¹-eKànëÕHTx}ýSÜ›ÿ ”7Ø×&µ<¦  ¥ÑO¶[Ù¯ä¨ÞÃÿ PZ-¬;#õ|•oaÿ ©CìÞz3˜öː/¤­ñTûIØ}š^ mÓ%ªxˆ¥ÉŸu=Z+ISe¿45™¼u;ú&WØ÷€æßQ™®{|íx*TC“#ZŠìZ§²‹ 6pv…³¿¡äª*áZÐ%ÒOáˆo"x«OHk w±æ+¬V(kMúŸ5Vö«$ ÁrÏbàb57/luR ¸ÑÛj Òµì`Ðœq­û žICÀÊ•©4€Âcà¨Ï€O´<èÐ:›ù(Ë^L8þ‘ÍÌ#¸Ð_Ì©ÙK(Öz 4¬û+¸;ü’V’84‘¬ÃŽ:[â‡ÔÌáõp¢~§ªlæ£ö{®G>J¼"°‡7¯ÆÉèßû ‹É‹§ÁòÃýâßî ^ƾÙõ‹×óH#«LP½ïX=xÑÍ$|W?•~• îëÔ©ª‹ {ÝT…Kÿ ”hûâá)J*ö˜–ÔU;iÇ€/ ÆþjóZ\ýwØ=Ìm ºèËL9 ýèÆð/¨’¥öo=nË.%Îì ŽÕ¯È|{Oj²ƒE6e/ßdÄõ²Ìâ1O®ò×TsəԸhOMýíMˆ¿¼H˜l²,7Â¥#MF/Úf°Ö½± ¸–dr‹NýÊ íjqx{œÉ ä-È ¦ øÄër¨q°ð †nцýÑÄÆ’mä…n<0È™;ÁÝá¯ÁZƒ7FÀmì­ É&9ˆîéi¶ùN§Y• ÃZãAâ?•‡©‰ , ó¾IŸŠc1 4â&y­&pŠ­6;M À 0¹qç»p.á …ŸÅáK@%6·y6ƒ‰3?”úºŽ‰éX5ªPT §µ!=Mž«Ú½‹ÅgÂSâÉaþÓoö–¯ÁÔìR>5éÿ üs¶ÆUcÌ kÇR ]ÿ ù¬¼«VŽ;Â|‡~¢¦”ÏÅ°æ {L™Õ°Óv¹ò¸írŽ¡×¢CÃ!íVÕ {¶»sŒNPg/ "uÕbkm²“$ďå¿é¹§°½æz¯6 †s¿!s–wÚÝ“™Œ °.ûj>·+™Òa…©Œ&rÝÎtÛë긪Ît’LAVp%c Úý[ÄzJ¾ÇàXXç@˜ó<êL]·T˜¾¥1Ó©V‡g´æ½¦Ý@¹óø!_@´ÞâSÁ —S3™•& ]@JHÚý©ZŽ €×æÔr»Áf!‡yÞ4Mv*èÓã_{‘åóUuљØ«Oïé*®EvÑ Œ÷‡U \"㪒ÍK+À 4“M¡ï:0¥5í!'<@î´”>Ç»&Z–ïCCV˜Ì5Šo&îhè.žû |ÓK©h$s6KìŒëã)¹hI¦GïOåóI;ììü#É$Š0…Ææ¥TØ.5­¾gn´ “ÂÖ\:hœ89G)J@„}œ:’Ò{/Š"¦_Æ×7Æ3VÇŠÊa]ÚŒÙ€Ä–=®uÁßâACZƒ§§£ Qnâ:«,×{tyø¬iÛcœÜÄ€H½ÄÍCk´÷šß .W'b¤Íåh]÷€=,Žv×cÚEÚHXJX¶îo¨FÒtèöŸ>ªª6[J®Fµ£sGÁeqõfe\íjÒÐïÄÐGˆe1Ø‹.Ø”‘Ëuø Y­ˆÜ ŽG|zùªüMpDnQWÄ”%JŠ™)â*p@Örš«ÕT2Ð%ˆG#ª„ ·¤!°ŸOTÂT¸aÚ%4&h™LµšØüÐ.F¿²ÐÞ_Ç‚¾ÅÃaÜ÷09Æ q€öy˜v‡85õN÷]¬äѼóS{°_MŽ¬úÔ#°Ç¸0åÞè2ëôPcvÆw9®ií1Ä8F™˜à‰´+‰Ik1òÝ7“Ñ×ÒsÝ\x‚h`ÞÑ`ó"|µEcý£n˜h`}GÞ !±ù²Ápü²ß6 0ïi󜵩SÈÇ7˜-ÕURO˜¦´f$ªž-Í6(œ}<„ éc øs]ŽŽ„*—¾ ìdŽ„)méª\¿êÎIg¾ØÞ~I#C/¼¼´EÁÈŽi8“©õådô·>euä ƒ'Ê×लR1ÉJE1ÐAát`t;ÇР%Ý<‡¥„ÍÆ`×Oyó)õiI€ñQaŸ4Ûù\áàaÃÔ¹HÃu¹*k€¦<„e S‡&õÏ B!ŽhüÞ`yj}mªf×\¿ Ç~æ­9‡û\՞Ǖg²1Žû5V7 !àöšm° c`ܬøÇìµÒ'P"?…´Ö,"§^•õŽ¨sÔ)6˜sæéÍR¼ ò|Sl”‹7 nPW Gòú÷½§O¯‡„l¡kSÞŒr½PÊ@æ¢pŽ-mÿ #Ÿ˜Àº¶Áä¦;ïÔæ$1££`“Õ>„—·ž)ßð³ñ#Ï Ô$¶œ‰ÊE‹À;÷º ¯«P:Ñ”8–IÊtpÞ3ª“>ê“þës4ò2OÏÕ­±zô†Õ§‰.÷ä¸;¿˜“'œ›žª}«Œ{ª±Ì 9ÔóÞÕ‡0 $íWV3Üì¬ —@kÝ4@¿r¼±½¬™›?øØæ´'Áé®CË3-g$˜ö‡×auÚi´Žp/êÛ æF›Ú2v‹ã¿¿,nB1̨ƃqÞa5͝@&Æû“él÷ \C²½UÍc ¯k×¢U ÖéQå™—-r wô ÞÏ<Ò=&=ÿ Ôê Òêˈt,i—;LîÜ á¸*ÚÃ1$êL•LÍ <É)ýÐà’ ;F™{ƒ™˜€&'}‚ãÄK`¡ÞT@I;®žZóè‚s’7®°›+§O­Åq©é»²9<Ô J ¼9O’HL»Ùïì¸rk¼Ž_ý‘TŸu[²ßÚŒ·ü÷B%¯E ŸÔX5êO´ Ç•€’I0 ÉJX` ñ¹õ%;µŸD‘«´€àwÒ™U ûئžÖö\×®×´8 ½‡ºÐÆÓ§?Àkmœ=;d5*@-ì0F Rªýš[Ü6âö̃ڸr*KA9· u*µæ£?U¸Âêí†8@¦X4 e-ò„0s{ HâUpU?¼mñRa°®a%Ð'tÉ×’\¾ÊÉ]t›h>·(Ë@R¼¡Ãt h}’O÷au<+nT…Ö…MӐ??Óe95 q>í/;&JSû °¯ÊéÞ øƒ*Ã2½Ài&:nôUl=¾¿5eˆ3”ñc|Ú2V”>„»&eE;«ÚäC p¢Û úy 9š[ŒÌx¼擼A&DåÒ¯ˆ¤ÀÌ;"˜ ÏQä¸åhÊ}Ûq«Û0WžÒ|»€ø®öCm5•\ÇÀ§Pe3£]0ÃàLDÉ‰1øªxjgwT‚÷¿LΨK‹›ùs—xˆÜ±µ kæ¸f‰‰ÜGk/LÛØ6d9ò¶ùA{ƒA3š/¬D¬khÓk‰`˜"㯒r¿±Óã jx‡°e}<Ñø\3y:'À•/h½Í€Ç4~g ?Û(¼]v‘ªlKÎâ~?O‚W%{Ì:“'©úNq¾›úo(X’¥¯ˆ nFê{Ç€ü?º'ë ø‹ì Þ09ŒÌç9Æ —ËC`j@ÓÄ(+a‹un¸#ÂꟋ{K`‘ÑÍÍ'à´»/Û,KW;Þ4²þð ï Nm|~fGÏ(…³Ã)«1ö­Õ ¥‡¨©ƒÃ™ü-s=à=U66Ï«Ýc蓦W¹íž®›nÔ%êÇìŒ<#Ü×84ån®Ð ÒåOC` ñânÑs‡¢ç 1õ%Îhì½Ã½® e:ݼUZo™`  ÅZŸŒÊ«ê1ÏÄo$q¹Þ€©ˆhÐÉä¯ñ[!…Ú˜àJ:x2$Íß&PåT£6ç— ‡Í*4Ýšçjÿ ‰É nófÐ ó(L5C•åÆ\rMÒ@ò }y-W}™üýVù—ú¢=Ù”c®‘< M ž ´Phr ¦©TD ‘ù.$´÷O‡‘V2Æò.=IUŒ=ž‡â¬i™aþÓåÙ?òUø'ØÖ•.~* šTŒ!•-×áºTâ®ä#õü'´ eýlYÅÓeÕKÂrT"CÚ@u!Óxƒ{š3€}1¿(r}%«nËamjÑ%ÑNEò v ˜à  σöK³,*º.àzù¨™Ó ÚçâU¦*¿ 9{%Ö¹ njûdaXöb) kÛƱûÓ\°M7ˆÂ=û›ç¿Ã‚­V»Cg–8ÙêE- j)k$º`Ã-ùEýeBÆÇ]c¡°ñty&Òd0nõ'¡W+ƒ*|–øµFa\GQªEAÔp5\Ǽ·¼Ç8·õ -â§Ú[ ‡ uZeÖ 3}×d'+¹:ð+K†Û®s!Ï$úe€<Û”x)1»a­¡LC]¸µík…ÚàA»AYº{†ªS[¦5HÒ7ù --,ísòDØ€èk ÞÀîÜ ò@â( ËNˆë›4ô½•/¦o‡€Û7 ê•ÆêòðÜy'Án½µ á˜ݦ ndeo…[ì¶Ê,¥R³Ä=À±—–ß;£™´ñSâ*g§”ïaið‘Jå~™ÓÞ ß³Õ¢»8x埒²52>AÊb&-÷\7´éÄù€T˜,w;3{ï˜k…à¹ÄqÀ«œ{€\ ˆ¾[´¨јr &Úé„Ívˆ±8†¿]|¬ņ4I×pÞS1ÈÖz‰#Ìv‡G!YNògñ:màTz¢Ý1ô©^O=~ë|5Bã™ç•¼µõ•bÆ@úÕS¬ÈŒ#¬zünrŸ û” Z²•ï›èðV"ÁHÚý©wÝ €7¼Ìu1hÑa3Éä û f$o¿É ™Ú›ÝçnpÒ3äÌ3†Í§,Äï]$‰/pê †«À¼¸e9­Æê_C]žƒ·ý·frÁN«, E=›Çq -‰öŒ:aÏ¿±í&£Í:-} 84‘ÿ eƒQÑeëSsuiA ³g㟥ú£?ÿ ʼn*”“÷aühe:ÊWa@ÒÞk±eØ] F Ô—r.åä˜ @ö¥ªZoÐýYL·¥S²G/‡ñ <~*ZÆ´è>JlòàÛƽÿ 窘ìGN¢:I®KšJp/`íIÁÀõ#Ä-€ö­šµŒoF4|ÆQØÆ@Ì|£Ô…¢À{9˜è½Üó›€ôYÒÎYsið;ís¤€à²ˆ‚4qÉVŒI$ ‰"° æµ8cXGjœˏ¡Aâý•ËÜ¢ûï e·çLx']á"oÅÎê3¯Ç—¹”ó0nå‚âg{Œñ> S´˜îè°g238‚ãköÝfÚd´6Ò€;ò÷±¢™¼›º ¢Æ'¥Ðx'e¬ç ]bÈÆV¢ó‹kýBO ðÊâ$Ÿ!×T 3Mýמ žìٍàÌü‘8÷€àæØ8æ©6‰©L´«…oãpð„~Çk‰!ñ;‹”ÛžÍ àž±z Ÿôû øŸÝužÏ;ÿ #|u6™Þ¬ÚˆÐõA4¶â|ôl|Ê2ŽÇ¤ÝÅÇY.<#Aí.k§hóF‚”Y; M½Ö4hŸ4&›­¿tès´%FìL¥£Ãk‰ÇT¤haÁ¤ÚxfÉ`ÑìË›>i 3t‚:,–+^÷´–{Û–Nxi"x‘Ûg î¨>¥Õ܁ùZH,2Û“:8xÊ¢Çí9.É-Ìâã-=çjwµS˜dütžçwýGòú®®ûº_ˆýx$–¡ãøO EÚÛÏ÷R„×w+3£Á£öUMyR²¹âŒ°š›¸Ñãò9§Ó_Dl+Ùßc›úšGÅÌc†Ž!Ko=¶.‘Îÿ c²(2®V mª.ÿ ¹B›¹å ù„öŸSV>™ü¯$y:G¢Z×àøúdî¹û­·ýÇ´:•c LÍõi_‹ö+ÎæGÊè>OŠ•äž´§Þ{X}¨1ÚTc›»Qþ•êô°t¿OP?eæ~É{5]•ÙR£r5†nZ\ã@ &îJõ ¾àC°þV>fé¥/ü5ñÊIº_é5 ;e­h<@ Ä&æÃëE%;X,ÒãÆÞ`Oò¦kŸm#˜!ÀyÄ¢| óLšò¥Ä` ¶R=|ÈCâh5ò3DˆïF†ðÒ#ÅìÛœ?¸yhBãœí ZxßÎÄhºRK„`Þödvײ™ÀÈÑÒgŒuY w³%†ƒÓzõ ÖÏp‚dH®¦A´ù§»ÓÇMæ~)ˆð‡û:ù&Ä •vGD´À n ݇¼Ö8Fö óáà£~Ë¥x`oK|Ä?fxiØü%pìR>éò+Û±éÎ>núlFŤ'tq8LZÏvÃ?„¡ß±È⽆¯³íü@x|PöUäèØã¡ð‚ŒAìÏ"vÍwóŸÍ{ ý0.z È•Ö{,N¡£¡ŸKÕÙž>Ýœþ ÍÀ°<×EA!Å‚D™IúOÍ¡>ôG}Â` ÍßkÜL™Ž Þð™ {IøF²¹òQ3&!ÃÂÞz.d&Ï-sH¸,Ôõ˜ŽP€ 77ˆÝ¼ÊëÜw =cÕ Ú,ØÐ5ÎYÐ)ì´öœgŒ[¤ßv㙑8心>h]§µháYš£²ºÑ.{Ï7Sð•?´~×SÃKýJÛ˜ ™Íäiúu<µX¶1õ^kâçIÑ£sZ4h>j*ÔšD:4­¿_ ÷¸ Õxæÿ ¸?Mù _•­ÊÐ ä ÷ý ÑwL œ­ïnTkÛUÍN©ë:¦fV ¶ÜÔÜMªÅâA½–¿R×TXš-%iTÊT•‡Ù‚JôϐZxWÑè‰f‰òG º ×Õû2aZ7OU3[“×AT–ÞŒ…-‘¤”Ì ì&(ˆ¿­•ƒkï’:ðY¦W‘ Å)“†‘˜³Åtcø˜ñTÂwÚÇ4|üLÇªí–v- qˆèU qPE.†â‘˜µ Æ,ÐÅs]8¾„oúÑ i>ÜxxÈó)ƒ ´æÁâØ$À‰vžŸf$Ž |ãw;ÀÁIJ»b` {¦Ó¤Ú$©YÀ‘n@Óïž«9J¼êG m¤ ܯ¹ÌW4€ÐÒÅÛ‡#褕Ÿn-?í|с¥÷Ú¹¬'´ÞÜ9ÓK `hê£SÄSà?7—Wí_´…óB›»:=Ãïq`<8ñÓŒÑlú2d¬ê³£hÖ[l|$vÝro~'R®‰§°ñmY ͧäP |PUª¹·:3Œ[Û{Xÿ ºâ@‚W–Äé u‚ ¯´*=íή.pûÒdt @G‰¬ s¸ ëÉücr ÞæѨÊ@>¤¢Ö±. Þ'¯°ÌME[YéïĵÂCå½ Ué©Áû'Ê9%eÔðNU”ë‘ÌsD3/®+UI˜9h.WC”빓$#:pz:YÓ ¿xž* ³$Í +$kñAŠ‹†¢ Uê>¸)_š¬÷©ßAÂÔb9ÇU ¯¾á•9¯ÏÏ÷O÷¼¼Fähal1‰3Ì[Ïr•´UCksNÐ] R‘¸¥H+§Šé†c©vÖÞ0iÓ76s†î!§=ß ¼~Ô'°Ãmäoäš³ªøi1úÉ)³yV8 CLÄØÁ‘WYïi€H6ÖÑiámø^ÈY´°Ñ7¥Û*—Ñ©L«Qƒï—Ùrÿ ›£Ð*š¸ˆL©ˆ$ˆ ÷¾D§9È®«qbqC)–ˆïv´çñsÑVT­Ø, <àïºÀO«Jý·õ àfPìð .wFšir´þ’2_Y *Æ€x\« ì€9š@ Ž|F⇥ˆkZ@hÖÄ0t¿-<“‹qµ¾*ZL¤Ú)&BJpÓF5=$„at*Zš$’ÑtdûÝRI1 2Ž‰$€$I$#‰SÞ’Hë¬ï;Á$¡t$’`<(ñÇt)$‡Ð.Êf¢X’Kt=Éé$‚ˆªè¢oÝëòI%Rgcª÷ŠyI%¡‰ÿ !ñ)´õ $¤ Ô’IIGÿÙ"""Handwritten parser of dependency specifiers. The docstring for each __parse_* function contains ENBF-inspired grammar representing the implementation. """ import ast from typing import Any, List, NamedTuple, Optional, Tuple, Union from ._tokenizer import DEFAULT_RULES, Tokenizer class Node: def __init__(self, value: str) -> None: self.value = value def __str__(self) -> str: return self.value def __repr__(self) -> str: return f"<{self.__class__.__name__}('{self}')>" def serialize(self) -> str: raise NotImplementedError class Variable(Node): def serialize(self) -> str: return str(self) class Value(Node): def serialize(self) -> str: return f'"{self}"' class Op(Node): def serialize(self) -> str: return str(self) MarkerVar = Union[Variable, Value] MarkerItem = Tuple[MarkerVar, Op, MarkerVar] # MarkerAtom = Union[MarkerItem, List["MarkerAtom"]] # MarkerList = List[Union["MarkerList", MarkerAtom, str]] # mypy does not support recursive type definition # https://github.com/python/mypy/issues/731 MarkerAtom = Any MarkerList = List[Any] class ParsedRequirement(NamedTuple): name: str url: str extras: List[str] specifier: str marker: Optional[MarkerList] # -------------------------------------------------------------------------------------- # Recursive descent parser for dependency specifier # -------------------------------------------------------------------------------------- def parse_requirement(source: str) -> ParsedRequirement: return _parse_requirement(Tokenizer(source, rules=DEFAULT_RULES)) def _parse_requirement(tokenizer: Tokenizer) -> ParsedRequirement: """ requirement = WS? IDENTIFIER WS? extras WS? requirement_details """ tokenizer.consume("WS") name_token = tokenizer.expect( "IDENTIFIER", expected="package name at the start of dependency specifier" ) name = name_token.text tokenizer.consume("WS") extras = _parse_extras(tokenizer) tokenizer.consume("WS") url, specifier, marker = _parse_requirement_details(tokenizer) tokenizer.expect("END", expected="end of dependency specifier") return ParsedRequirement(name, url, extras, specifier, marker) def _parse_requirement_details( tokenizer: Tokenizer, ) -> Tuple[str, str, Optional[MarkerList]]: """ requirement_details = AT URL (WS requirement_marker?)? | specifier WS? (requirement_marker)? """ specifier = "" url = "" marker = None if tokenizer.check("AT"): tokenizer.read() tokenizer.consume("WS") url_start = tokenizer.position url = tokenizer.expect("URL", expected="URL after @").text if tokenizer.check("END", peek=True): return (url, specifier, marker) tokenizer.expect("WS", expected="whitespace after URL") # The input might end after whitespace. if tokenizer.check("END", peek=True): return (url, specifier, marker) marker = _parse_requirement_marker( tokenizer, span_start=url_start, after="URL and whitespace" ) else: specifier_start = tokenizer.position specifier = _parse_specifier(tokenizer) tokenizer.consume("WS") if tokenizer.check("END", peek=True): return (url, specifier, marker) marker = _parse_requirement_marker( tokenizer, span_start=specifier_start, after=( "version specifier" if specifier else "name and no valid version specifier" ), ) return (url, specifier, marker) def _parse_requirement_marker( tokenizer: Tokenizer, *, span_start: int, after: str ) -> MarkerList: """ requirement_marker = SEMICOLON marker WS? """ if not tokenizer.check("SEMICOLON"): tokenizer.raise_syntax_error( f"Expected end or semicolon (after {after})", span_start=span_start, ) tokenizer.read() marker = _parse_marker(tokenizer) tokenizer.consume("WS") return marker def _parse_extras(tokenizer: Tokenizer) -> List[str]: """ extras = (LEFT_BRACKET wsp* extras_list? wsp* RIGHT_BRACKET)? """ if not tokenizer.check("LEFT_BRACKET", peek=True): return [] with tokenizer.enclosing_tokens("LEFT_BRACKET", "RIGHT_BRACKET"): tokenizer.consume("WS") extras = _parse_extras_list(tokenizer) tokenizer.consume("WS") return extras def _parse_extras_list(tokenizer: Tokenizer) -> List[str]: """ extras_list = identifier (wsp* ',' wsp* identifier)* """ extras: List[str] = [] if not tokenizer.check("IDENTIFIER"): return extras extras.append(tokenizer.read().text) while True: tokenizer.consume("WS") if tokenizer.check("IDENTIFIER", peek=True): tokenizer.raise_syntax_error("Expected comma between extra names") elif not tokenizer.check("COMMA"): break tokenizer.read() tokenizer.consume("WS") extra_token = tokenizer.expect("IDENTIFIER", expected="extra name after comma") extras.append(extra_token.text) return extras def _parse_specifier(tokenizer: Tokenizer) -> str: """ specifier = LEFT_PARENTHESIS WS? version_many WS? RIGHT_PARENTHESIS | WS? version_many WS? """ with tokenizer.enclosing_tokens("LEFT_PARENTHESIS", "RIGHT_PARENTHESIS"): tokenizer.consume("WS") parsed_specifiers = _parse_version_many(tokenizer) tokenizer.consume("WS") return parsed_specifiers def _parse_version_many(tokenizer: Tokenizer) -> str: """ version_many = (SPECIFIER (WS? COMMA WS? SPECIFIER)*)? """ parsed_specifiers = "" while tokenizer.check("SPECIFIER"): parsed_specifiers += tokenizer.read().text tokenizer.consume("WS") if not tokenizer.check("COMMA"): break parsed_specifiers += tokenizer.read().text tokenizer.consume("WS") return parsed_specifiers # -------------------------------------------------------------------------------------- # Recursive descent parser for marker expression # -------------------------------------------------------------------------------------- def parse_marker(source: str) -> MarkerList: return _parse_marker(Tokenizer(source, rules=DEFAULT_RULES)) def _parse_marker(tokenizer: Tokenizer) -> MarkerList: """ marker = marker_atom (BOOLOP marker_atom)+ """ expression = [_parse_marker_atom(tokenizer)] while tokenizer.check("BOOLOP"): token = tokenizer.read() expr_right = _parse_marker_atom(tokenizer) expression.extend((token.text, expr_right)) return expression def _parse_marker_atom(tokenizer: Tokenizer) -> MarkerAtom: """ marker_atom = WS? LEFT_PARENTHESIS WS? marker WS? RIGHT_PARENTHESIS WS? | WS? marker_item WS? """ tokenizer.consume("WS") if tokenizer.check("LEFT_PARENTHESIS", peek=True): with tokenizer.enclosing_tokens("LEFT_PARENTHESIS", "RIGHT_PARENTHESIS"): tokenizer.consume("WS") marker: MarkerAtom = _parse_marker(tokenizer) tokenizer.consume("WS") else: marker = _parse_marker_item(tokenizer) tokenizer.consume("WS") return marker def _parse_marker_item(tokenizer: Tokenizer) -> MarkerItem: """ marker_item = WS? marker_var WS? marker_op WS? marker_var WS? """ tokenizer.consume("WS") marker_var_left = _parse_marker_var(tokenizer) tokenizer.consume("WS") marker_op = _parse_marker_op(tokenizer) tokenizer.consume("WS") marker_var_right = _parse_marker_var(tokenizer) tokenizer.consume("WS") return (marker_var_left, marker_op, marker_var_right) def _parse_marker_var(tokenizer: Tokenizer) -> MarkerVar: """ marker_var = VARIABLE | QUOTED_STRING """ if tokenizer.check("VARIABLE"): return process_env_var(tokenizer.read().text.replace(".", "_")) elif tokenizer.check("QUOTED_STRING"): return process_python_str(tokenizer.read().text) else: tokenizer.raise_syntax_error( message="Expected a marker variable or quoted string" ) def process_env_var(env_var: str) -> Variable: if ( env_var == "platform_python_implementation" or env_var == "python_implementation" ): return Variable("platform_python_implementation") else: return Variable(env_var) def process_python_str(python_str: str) -> Value: value = ast.literal_eval(python_str) return Value(str(value)) def _parse_marker_op(tokenizer: Tokenizer) -> Op: """ marker_op = IN | NOT IN | OP """ if tokenizer.check("IN"): tokenizer.read() return Op("in") elif tokenizer.check("NOT"): tokenizer.read() tokenizer.expect("WS", expected="whitespace after 'not'") tokenizer.expect("IN", expected="'in' after 'not'") return Op("not in") elif tokenizer.check("OP"): return Op(tokenizer.read().text) else: return tokenizer.raise_syntax_error( "Expected marker operator, one of " "<=, <, !=, ==, >=, >, ~=, ===, in, not in" )