Make some progress on good parser errors

This commit is contained in:
Scott Richmond 2022-02-20 19:33:24 -05:00
parent 3fde2cb52b
commit a4cecc3d01

View File

@ -102,8 +102,13 @@
(::token/comma ::token/newline) (recur (advance parser) (add-member members current_member) nil)
(let [parsed (parse-expr parser)]
(if (= ::ast/poison (get-in parsed [::ast ::ast/type]))
(panic parsed (:message (::ast parsed)) #{::token/rparen})
(if (poisoned? parsed)
(let [
panicked
(panic parser (get-in parsed [::ast :message]) #{::token/rparen})
]
(recur panicked members (::ast panicked))
)
(recur parsed members (::ast parsed))
)
)
@ -242,7 +247,7 @@
(advance parser)
(-> parser
(advance)
(assoc ::ast {::ast/type ::ast/poison :message message})))))
(panic message #{token})))))
(defn- accept [token parser]
(let [curr (current parser)
@ -258,21 +263,22 @@
(recur (advance parser))
parser))))
(defn- parse-let-expr [parser pattern]
(let [expr (parse-expr parser)]
(assoc expr ::ast {::ast/type ::ast/let
:pattern (::ast pattern) :expr (::ast expr)})))
(defn- parse-assignment [parser]
(let [assignment (expect ::token/equals "Expected assignment" parser)]
(if (poisoned? assignment)
(panic parser (get-in assignment [::ast :message]) #{::token/newline ::token/semicolon})
(parse-let-expr assignment parser))))
(defn- parse-let [parser]
(let [
pattern (parse-pattern (advance parser))
equals (expect ::token/equals "Expected assignment" pattern)
expr (parse-expr equals)
results (map #(get-in % [::ast ::ast/type]) [pattern equals expr])
]
(if (some #(= ::ast/poison %) results)
(println ::poison)
(assoc expr ::ast {
::ast/type ::ast/let
:pattern (::ast pattern)
:expr (::ast expr)}))
))
(let [pattern (parse-pattern (advance parser))]
(if (poisoned? pattern)
(panic parser (get-in pattern [::ast :message]) #{::token/newline ::token/semicolon})
(parse-assignment pattern))))
(defn- parse-if [parser]
(let [
@ -358,10 +364,8 @@
(do
(def pp pp/pprint)
(def source "(foo, bar, baz^, } )
:foo (bar)
[1, 2, 3]")
(def source "(12, 43, arf@)
")
(def lexed (scanner/scan source))
(def tokens (:tokens lexed))
(def p (parser tokens))
@ -379,7 +383,7 @@
- use accept-many in blocks and scripts
- ast nodes should include their tokens (this is added for atoms, which may be fully sufficient)
* Time to start working on parsing errors (poisoned nodes, panic mode, etc.)
- this works (ish) for expr, script, tuple
- this works for expr, script, let, tuple (this one was titchy--and still runs away on unmatched parens)
- add to everything else
- investigate duplicated/missing error messages