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Parse basic list, hash, struct patterns.

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This commit is contained in:
Scott Richmond 2022-05-19 19:14:25 -04:00
parent ad778f7104
commit a899ee776d
1 changed files with 111 additions and 3 deletions
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112
src/ludus/parser.clj
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@ -450,6 +450,106 @@
(def sync-pattern (s/union sync-on #{::token/equals ::token/rarrow}))
(defn- parse-list-pattern [origin]
(loop [parser (accept-many #{::token/newline ::token/comma} (advance origin))
members []
current_member nil]
(let [curr (current parser)]
(case (token-type parser)
::token/rbracket (let [ms (add-member members current_member)]
(assoc (advance parser) ::ast
{::ast/type ::ast/list
:token (current origin)
:members ms}))
(::token/comma ::token/newline)
(recur
(accept-many #{::token/comma ::token/newline} parser)
(add-member members current_member) nil)
(::token/rbrace ::token/rparen)
(panic parser (str "Mismatched enclosure in list pattern: " (::token/lexeme curr)))
::token/eof
(panic (assoc origin ::errors (::errors parser)) "Unterminated list pattern" ::token/eof)
(let [parsed (parse-pattern parser)]
(recur parsed members (::ast parsed)))))))
(defn- parse-hash-pattern [origin]
(loop [parser (accept-many #{::token/newline ::token/comma} (advance origin))
members {}
current_member nil]
(let [curr (current parser)]
(case (token-type parser)
::token/rbrace (let [ms (add-member members current_member)]
(assoc (advance parser) ::ast
{::ast/type ::ast/hash
:token (current origin)
:members ms}))
(::token/comma ::token/newline)
(recur
(accept-many #{::token/comma ::token/newline} parser)
(add-member members current_member) nil)
(::token/rbracket ::token/rparen)
(panic parser (str "Mismatched enclosure in hashmap pattern: " (::token/lexeme curr)))
::token/eof
(panic (assoc origin ::errors (::errors parser)) "Unterminated hashmap pattern" ::token/eof)
::token/word
(if (not current_member)
(let [parsed (parse-word parser) word (get-in parsed [::ast :word])]
(recur parsed members {(keyword word) (::ast parsed)}))
(panic parser "Hashmap patterns may only include single words or keyword+pattern pairs." #{::token/rbrace}))
::token/keyword
(if (not current_member)
(let [kw (parse-atom parser) pattern (parse-pattern kw)]
(recur pattern members {(:value (::ast kw)) (::ast pattern)}))
(panic parser "Hashmap patterns may only include single words or keyword+pattern pairs." #{::token/rbrace}))
(panic parser "Hashmap patterns may only include single words or keyword+pattern pairs" #{::token/rbrace})))))
(defn- parse-struct-pattern [origin]
(loop [parser (accept-many #{::token/newline ::token/comma} (advance origin))
members {}
current_member nil]
(let [curr (current parser)]
(case (token-type parser)
::token/rbrace (let [ms (add-member members current_member)]
(assoc (advance parser) ::ast
{::ast/type ::ast/struct
:token (current origin)
:members ms}))
(::token/comma ::token/newline)
(recur
(accept-many #{::token/comma ::token/newline} parser)
(add-member members current_member) nil)
(::token/rbracket ::token/rparen)
(panic parser (str "Mismatched enclosure in struct pattern: " (::token/lexeme curr)))
::token/eof
(panic (assoc origin ::errors (::errors parser)) "Unterminated struct pattern" ::token/eof)
::token/word
(if (not current_member)
(let [parsed (parse-word parser) word (get-in parsed [::ast :word])]
(recur parsed members {(keyword word) (::ast parsed)}))
(panic parser "Struct patterns may only include single words or keyword+pattern pairs." #{::token/rbrace}))
::token/keyword
(if (not current_member)
(let [kw (parse-atom parser) pattern (parse-pattern kw)]
(recur pattern members {(:value (::ast kw)) (::ast pattern)}))
(panic parser "Struct patterns may only include single words or keyword+pattern pairs." #{::token/rbrace}))
(panic parser "Struct patterns may only include single words or keyword+pattern pairs." #{::token/rbrace})))))
(defn- parse-tuple-pattern [origin]
(loop [parser (accept-many #{::token/newline ::token/comma} (advance origin))
members []
@ -492,6 +592,12 @@
::token/lparen (parse-tuple-pattern parser)
::token/lbracket (parse-list-pattern parser)
::token/starthash (parse-hash-pattern parser)
::token/startstruct (parse-struct-pattern parser)
::token/error
(panic parser (:message (current parser)) sync-pattern)
@ -912,9 +1018,11 @@
(parser)
(parse-script)))
(do
(comment
(def pp pp/pprint)
(def source "panic! foo
(def source "
let #{foo, :bar 23, 34} = #{:foo 42, :bar 23}
")
(def lexed (scanner/scan source))