Reposted by Vladimir Keleshev
@keleshev.com not sure whether you already saw, but Compiling to Assembly from Scratch got a review in c't 9/25 (the largest German IT magazine)
Vladimir Keleshev
@keleshev.com
806 followers 438 following 57 posts
OCaml programmer, author of Compiling to Assembly from Scratch: keleshev.com/cas Copenhagen
![@dataclass
class Parser[T]:
_parse: Callable[[Source], ParseResult[T] | None]
def parse(self, s: Source) -> ParseResult[T] | None:
return self.__dict__['_parse'](s)
@staticmethod
def regexp(regexp: Pattern) -> Parser[str]:
return Parser(lambda source: source.match(regexp))
@staticmethod
def constant[U](value: U) -> Parser[U]:
return Parser(lambda source: ParseResult(value, source))](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2epiemw5vmy4usnpcd7a7c5w/bafkreidhetpmve5dtzfsq7z26fovxhf5a2dfgftpjaiaj2ch5iqs74pdtm)
![# Recursive definition of pattern
required <- "(" _ pattern ")" _
optional <- "[" _ pattern "]" _
confined <- required / optional / atom _
multiple <- confined ("..." _)?
sequence <- multiple multiple*
junction <- sequence ("|" _ sequence)*
pattern <- junction](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2epiemw5vmy4usnpcd7a7c5w/bafkreiamybfq2vdp6mjzsb3rkudgzzgudfwzxpyszsmcbphxo5vgthakz4)
![let rec pattern x =
let required = token "(" %> pattern <% token ")" in
let optional =
let+ pattern = token "[" %> pattern <% token "]" in
Pattern.Optional pattern in
let confined = required / optional / atom in
let multiple =
let+ pattern, ellipsis = confined <%> maybe (token "...") in
if ellipsis = None then pattern else Pattern.Multiple pattern in
let sequence =
let+ first, rest = multiple <%> zero_or_more multiple in
List.fold_left Pattern.sequence first rest in
let junction =
let+ first, rest = sequence <%> zero_or_more (token "|" %> sequence) in
List.fold_left Pattern.junction first rest in
junction x](https://cdn.bsky.app/img/feed_thumbnail/plain/did:plc:2epiemw5vmy4usnpcd7a7c5w/bafkreichch7yyebee5hlkdr2k457b7znrw7ttbggyw7er7lhci7rcolnsu)