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Start work on if errors

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This commit is contained in:
Scott Richmond 2022-03-13 19:43:57 -04:00
parent a05feea32a
commit 83392e3ac4
1 changed files with 53 additions and 50 deletions
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103
src/ludus/parser.clj
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@ -61,7 +61,7 @@
(defn- panic
([parser message] (panic parser message sync-on))
([parser message sync-on]
(println (str "PANIC!!! in the parser" message))
(println (str "PANIC!!! in the parser: " message))
(let [
sync-on (conj (if (set? sync-on) sync-on #{sync-on}) ::token/eof)
origin (current parser)
@ -360,11 +360,11 @@
;; TODO: Fix failure case here
(defn- parse-if [parser]
(let [
if-expr (parse-expr (advance parser))
if-expr (parse-expr (advance parser) #{::token/then ::token/newline})
then (expect ::token/then "Expected then" (accept ::token/newline if-expr))
then-expr (parse-expr then)
else (expect ::token/else "Epected else" (accept ::token/newline then-expr))
else-expr (parse-expr else)
else-expr (parse-expr else #{::token/else ::token/newline})
results (map #(get-in % [::ast ::ast/type]) [if-expr then then-expr else else-expr])
]
(if (some #(= ::ast/poison %) results)
@ -377,55 +377,58 @@
}))
))
(defn- parse-expr [parser]
(let [token (current parser)]
(case (::token/type token)
(::token/number ::token/string)
(parse-atom parser)
::token/keyword (let [next (peek parser)
type (::token/type next)]
(if (= type ::token/lparen)
(parse-synthetic parser)
(parse-atom parser)))
::token/word (let [next (peek parser)
type (::token/type next)]
(case type
(::token/lparen ::token/keyword) (parse-synthetic parser)
(parse-word parser)))
(::token/nil ::token/true ::token/false)
(parse-atomic-word parser)
::token/lparen (parse-tuple parser)
::token/lbracket (parse-list parser)
::token/startset (parse-set parser)
::token/lbrace (parse-block parser)
::token/let (parse-let* parser)
::token/if (parse-if parser)
::token/error (panic parser (:message token))
(::token/rparen ::token/rbrace ::token/rbracket)
(panic parser (str "Unbalanced enclosure: " (::token/lexeme token)))
(::token/semicolon ::token/comma)
(panic parser (str "Unexpected delimiter: " (::token/lexeme token)))
(panic parser "Expected expression")
)))
(defn- parse-expr
([parser] (parse-expr parser sync-on))
([parser sync-on] (let [token (current parser)]
(case (::token/type token)
(::token/number ::token/string)
(parse-atom parser)
::token/keyword (let [next (peek parser)
type (::token/type next)]
(if (= type ::token/lparen)
(parse-synthetic parser)
(parse-atom parser)))
::token/word (let [next (peek parser)
type (::token/type next)]
(case type
(::token/lparen ::token/keyword) (parse-synthetic parser)
(parse-word parser)))
(::token/nil ::token/true ::token/false)
(parse-atomic-word parser)
::token/lparen (parse-tuple parser)
::token/lbracket (parse-list parser)
::token/startset (parse-set parser)
::token/lbrace (parse-block parser)
::token/let (parse-let* parser)
::token/if (parse-if parser)
::token/error (panic parser (:message token))
(::token/rparen ::token/rbrace ::token/rbracket)
(panic parser (str "Unbalanced enclosure: " (::token/lexeme token)))
(::token/semicolon ::token/comma)
(panic parser (str "Unexpected delimiter: " (::token/lexeme token)))
(panic parser "Expected expression" sync-on)
))))
(do
(def pp pp/pprint)
(def source "if *else then bar else baz")
(def source "if
then bar
else baz")
(def lexed (scanner/scan source))
(def tokens (:tokens lexed))
(def p (parser tokens))
@ -437,7 +440,7 @@
(println "*** *** NEW PARSE *** ***")
(-> p
(parse-script)
(parse-if)
(::ast)
(pp)
)