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Merge pull request #90 from jolt-lang/error-round-5

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errors: reader errors carry file:line:col (round 5)
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Dmitri Sotnikov 2026-06-12 15:15:39 +00:00 • committed by GitHub
commit ca83b4a1de
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5 changed files with 88 additions and 24 deletions
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2
src/jolt/api.janet
View file

@ -326,5 +326,5 @@
Returns the result of the last form evaluated."
[ctx s &opt file]
(default file "<eval>")
(eval-forms-positioned ctx (parse-all-positioned s) file))
(eval-forms-positioned ctx (parse-all-positioned s file) file))

2
src/jolt/evaluator.janet
View file

@ -361,7 +361,7 @@
[ctx src &opt file]
(default file "<source>")
(def toplevel (get (ctx :env) :toplevel-eval))
(each [f line] (parse-all-positioned src)
(each [f line] (parse-all-positioned src file)
(try
(if toplevel (toplevel ctx f) (eval-form ctx @{} f))
([err fib]

2
src/jolt/loader.janet
View file

@ -112,7 +112,7 @@
(load-ns ctx filepath) → namespace symbol string"
[ctx filepath]
(def source (slurp filepath))
(def pairs (parse-all-positioned source))
(def pairs (parse-all-positioned source filepath))
(var ns-name nil)
(each [form _] pairs
# Extract ns name from the first ns form

87
src/jolt/reader.janet
View file

@ -23,6 +23,36 @@
(= c 13) # \r
(= c 44))) # comma
# Reader errors carry the raw byte OFFSET; the parse entry points (parse-string,
# parse-all-positioned) convert offset -> line:col against the full source and
# re-raise Clojure's 'Syntax error reading source at (file:line:col): msg'
# shape. Raising structured here keeps the 15 error sites one-liners.
# (jolt-2o7.5)
(defn- reader-error [msg pos]
(error {:jolt/type :jolt/reader-error :msg msg :pos pos}))
(defn line-col
"1-based [line col] of byte offset in source."
[source offset]
(var line 1)
(var bol 0)
(def stop (min offset (length source)))
(loop [i :range [0 stop]]
(when (= (in source i) (chr "\n")) (++ line) (set bol (+ i 1))))
[line (+ 1 (- stop bol))])
(defn format-reader-error
"Clojure-shaped syntax error message for a reader-error struct raised
against source; file may be nil (omitted)."
[e source file]
(def [l c] (line-col source (e :pos)))
(if file
(string "Syntax error reading source at (" file ":" l ":" c "): " (e :msg))
(string "Syntax error reading source at (" l ":" c "): " (e :msg))))
(defn reader-error? [e]
(and (struct? e) (= :jolt/reader-error (e :jolt/type))))
(defn skip-whitespace [s pos]
(if (and (< pos (length s))
(whitespace? (s pos)))
@ -89,7 +119,7 @@
(defn read-symbol [s pos]
(let [end (read-symbol-name s pos pos)]
(if (= end pos)
(error (string "Unrecognized character at " pos ": " (string/from-bytes (s pos))))
(reader-error (string "Unrecognized character: " (string/from-bytes (s pos))) pos)
(let [name (string/slice s pos end)]
(if (= name "nil") [nil end]
(if (= name "true") [true end]
@ -126,12 +156,12 @@
(defn read-string-chars [s pos end chars]
(if (>= pos end)
(error "Unterminated string")
(reader-error "Unterminated string" pos)
(let [c (s pos)]
(if (= c 92) # backslash
(let [next-pos (+ pos 1)]
(if (>= next-pos end)
(error "Unterminated escape")
(reader-error "Unterminated escape" pos)
(read-string-chars s (+ pos 2) end
(array/push chars (escape-char (s next-pos))))))
(if (= c 34) # closing quote
@ -198,19 +228,19 @@
(= (s pos) 48) (or (= (s (+ pos 1)) 120) (= (s (+ pos 1)) 88)))] # 0x / 0X
(if hex?
(let [hs (+ pos 2) he (read-hex-digits s hs hs)]
(if (= he hs) (error (string "Expected hex digits at " pos)))
(if (= he hs) (reader-error "Expected hex digits" pos))
(let [he2 (if (and (< he len) (= (s he) 78)) (+ he 1) he) # trailing N
val (scan-number (string "0x" (string/slice s hs he)))]
[(if neg (- val) val) he2]))
(let [iend (read-digits s pos pos)]
(if (= iend pos) (error (string "Expected number at " pos)))
(if (= iend pos) (reader-error "Expected number" pos))
(cond
# radix integer: <base>r<digits>, e.g. 2r1010, 16rFF, 36rZ
(and (< iend len) (or (= (s iend) 114) (= (s iend) 82)))
(let [base (scan-number (string/slice s pos iend))
ds (+ iend 1)
de (read-alnum s ds ds)]
(if (= de ds) (error (string "Expected radix digits at " ds)))
(if (= de ds) (reader-error "Expected radix digits" ds))
(var acc 0)
(var i ds)
(while (< i de) (set acc (+ (* acc base) (radix-digit-val (s i)))) (++ i))
@ -238,7 +268,7 @@
(defn read-list-items [s pos items]
(let [pos (skip-whitespace s pos)]
(if (>= pos (length s))
(error "Unterminated list"))
(reader-error "Unterminated list" pos))
(if (= (s pos) 41) # )
[items (+ pos 1)]
(let [[form new-pos] (read-form s pos)]
@ -256,7 +286,7 @@
(defn read-vec-items [s pos items]
(let [pos (skip-whitespace s pos)]
(if (>= pos (length s))
(error "Unterminated vector"))
(reader-error "Unterminated vector" pos))
(if (= (s pos) 93) # ]
[(tuple/slice (tuple ;items)) (+ pos 1)]
(let [[form new-pos] (read-form s pos)]
@ -282,7 +312,7 @@
(defn read-kvs [s pos kvs]
(let [pos (skip-whitespace s pos)]
(if (>= pos (length s))
(error "Unterminated map"))
(reader-error "Unterminated map" pos))
(if (= (s pos) 125) # }
[(reader-map kvs) (+ pos 1)]
(let [[key new-pos] (read-form s pos)]
@ -321,7 +351,7 @@
(defn read-set-items [s pos items]
(let [pos (skip-whitespace s pos)]
(if (>= pos (length s))
(error "Unterminated set"))
(reader-error "Unterminated set" pos))
(if (= (s pos) 125) # }
[{:jolt/type :jolt/set :value (tuple/slice (tuple ;items))} (+ pos 1)]
(let [[form new-pos] (read-form s pos)]
@ -477,7 +507,7 @@
(set done [(struct ;[:jolt/type :jolt/tagged :tag :regex :form (string/slice s (+ pos 2) i)])
(+ i 1)])
(++ i))))
(if done done (error "Unterminated regex literal")))
(if done done (reader-error "Unterminated regex literal" pos)))
(defn read-dispatch [s pos]
# pos is at #
@ -499,7 +529,7 @@
(= name "Inf") [math/inf end]
(= name "-Inf") [(- math/inf) end]
(= name "NaN") [math/nan end]
(error (string "Invalid symbolic value: ##" name))))
(reader-error (string "Invalid symbolic value: ##" name) pos)))
# unknown dispatch — tagged literal
(let [end (read-symbol-name s pos pos)
tag (string/slice s pos end)
@ -581,13 +611,13 @@
# unmatched closing delimiters
(= c 41)
(error (string "Unmatched closing paren at " pos))
(reader-error "Unmatched delimiter: )" pos)
(= c 93)
(error (string "Unmatched closing bracket at " pos))
(reader-error "Unmatched delimiter: ]" pos)
(= c 125)
(error (string "Unmatched closing brace at " pos))
(reader-error "Unmatched delimiter: }" pos)
# vector
(= c 91)
@ -637,10 +667,15 @@
(defn parse-string
"Parse a Clojure source string and return the first form."
[s]
(let [[form pos] (read-form s 0)]
(if (and (struct? form) (= :jolt/skip (form :jolt/type)))
(parse-string (string/slice s pos))
form)))
(try
(let [[form pos] (read-form s 0)]
(if (and (struct? form) (= :jolt/skip (form :jolt/type)))
(parse-string (string/slice s pos))
form))
([err fib]
(if (reader-error? err)
(error (format-reader-error err s nil))
(propagate err fib)))))
(defn parse-next
"Parse the first form from a string. Returns [form remaining-string]."
@ -658,7 +693,7 @@
leading trivia itself, so the form's start line is the running newline
count plus the newlines in the trivia (whitespace, commas, ; comments)
ahead of it. (jolt-2o7.4)"
[source]
[source &opt file]
(def out @[])
(var s source)
(var line 1)
@ -674,7 +709,17 @@
(or (= c (chr " ")) (= c (chr "\t")) (= c (chr "\r")) (= c (chr ","))) (++ i)
(= c (chr ";")) (while (and (< i n) (not= (in s i) (chr "\n"))) (++ i))
(set scanning false)))
(def [form rest*] (parse-next s))
(def [form rest*]
(try (parse-next s)
([err fib]
(if (reader-error? err)
# err's :pos is relative to the remaining slice — rebase onto the
# full source so line:col are absolute (jolt-2o7.5)
(error (format-reader-error
{:jolt/type :jolt/reader-error :msg (err :msg)
:pos (+ (- (length source) (length s)) (err :pos))}
source file))
(propagate err fib)))))
(def consumed (- (length s) (length rest*)))
(def form-line line)
# count newlines inside the consumed chunk past the trivia

19
test/integration/cli-test.janet
View file

@ -86,6 +86,25 @@
(run-err "-e" `(+ 1 "a")`)
(fn [s] (nil? (string/find "<eval>" s))))
# --- round 5: reader errors carry file:line:col ------------------------------
(check "unterminated string positions in -e"
(run-err "-e" `(+ 1 "abc`)
(has "Syntax error reading source at (<eval>:1:10): Unterminated string"))
(check "unterminated list names script file:line:col"
(do (spit (string r4 "/syn.clj") "(ns syn)\n\n(defn f [x]\n (+ x 1\n")
(run-err (string r4 "/syn.clj")))
(has ":5:1): Unterminated list"))
(check "unmatched delimiter positioned"
(do (spit (string r4 "/app/synreq.clj") "(ns app.synreq)\n\n(def x ])\n")
(spit (string r4 "/app/top2.clj") "(ns app.top2 (:require [app.synreq :as q]))\n(defn -main [& a] nil)\n")
(os/setenv "JOLT_PATH" r4)
(run-err "-m" "app.top2"))
(fn [s] (and (string/find "/app/synreq.clj:3:8): Unmatched delimiter: ]" s)
(string/find "/app/top2.clj:1" s))))
(check "bad token positioned"
(run-err "-e" "(def x ##Huh)")
(has "Invalid symbolic value: ##Huh"))
(check "JOLT_DEBUG restores the raw trace"
(do (os/setenv "JOLT_DEBUG" "1")
(def r (run-err "-e" `(+ 1 "a")`))