jolt/jolt-core/clojure/core/50-io.clj
Yogthos 6445f461bb core: the last seven missing-portable vars — coverage gap closed (jolt-brh)
The dashboard's missing-portable category is now EMPTY (was 35 when the issue
was filed; this session's io/leaf work had already landed most of them).
The final seven:

- extenders — ctx-capturing clojure.core fn over the protocol type-registry:
  the type-tags implementing a protocol, as symbols; nil when none
- find-keyword — keyword: jolt keywords have no intern table, so it always
  finds (babashka makes the same call)
- inst-ms* — the raw Inst method; one inst representation, so = inst-ms
- read+string — over the 50-io readers, which now expose :buf and :fill-fn;
  returns [form exact-text-consumed], EOF throws or yields [eof-value ""]
  with the 3-arity, works for string AND stdin readers
- with-local-vars — fresh free-standing var cells (__local-var seam) bound as
  locals; var-get/var-set work on any cell
- with-open — canonical recursive expansion closing through the __close seam:
  a map-like value's :close fn or a host file (no .close interop here);
  nested closes run inner-first, finally runs on throw
- with-precision — body evaluates with precision/:rounding accepted and
  ignored (doubles, no BigDecimal context) — documented divergence

30 new spec rows (test/spec/missing-vars-spec.janet); coverage.md
regenerated: implemented+tested 426 -> 433, missing-portable 7 -> 0.
Gate: jpm exit 0, all tests passed.
2026-06-10 17:22:28 -04:00

129 lines
4.3 KiB
Clojure

;; clojure.core — IO tier: the *in* reader family (jolt-0d9).
;;
;; *in* is a dynamic var holding a READER: a plain map whose two ops close
;; over their source — :read-line-fn (next line, newline
;; stripped, nil at EOF) and :read-fn (next FORM, advancing past exactly that
;; form; the eof sentinel at end of input). The default *in* reads real stdin
;; through the host seam __stdin-read-line, with a shared leftover buffer so
;; read and read-line interleave; with-in-str rebinds *in* to a string reader
;; over one atom-held buffer, so (read) consumes its form and a following
;; (read-line) returns the REST of that line — as in Clojure.
;;
;; Forms are parsed by the host seam __parse-next (one form + the rest of the
;; string, nil when only whitespace remains). Known wart shared with that
;; contract: input that is only a comment reads as nil rather than EOF.
(def ^:private reader-eof :jolt/reader-eof)
(defn __string-reader
"A reader over string s (the with-in-str expansion calls this)."
[s]
(let [buf (atom s)]
{:buf buf
:fill-fn nil
:read-line-fn
(fn []
(let [cur @buf]
(when (pos? (count cur))
(let [i (str-find "\n" cur)]
(if (nil? i)
(do (reset! buf "") cur)
(do (reset! buf (subs cur (inc i))) (subs cur 0 i)))))))
:read-fn
(fn []
(let [r (__parse-next @buf)]
(if (nil? r)
reader-eof
(do (reset! buf (nth r 1)) (nth r 0)))))}))
;; Real stdin, with a leftover buffer shared by read and read-line: read may
;; pull a whole line to parse a form and must hand the remainder to the next
;; read/read-line.
(def ^:private stdin-buf (atom ""))
(def ^:dynamic *in*
{:buf stdin-buf
:fill-fn (fn []
(let [line (__stdin-read-line)]
(if (nil? line)
false
(do (swap! stdin-buf (fn [b] (str b line "\n"))) true))))
:read-line-fn
(fn []
(let [cur @stdin-buf]
(if (pos? (count cur))
(let [i (str-find "\n" cur)]
(if (nil? i)
(do (reset! stdin-buf "") cur)
(do (reset! stdin-buf (subs cur (inc i))) (subs cur 0 i))))
(__stdin-read-line))))
:read-fn
(fn []
(loop []
(let [r (__parse-next @stdin-buf)]
(if (nil? r)
(let [line (__stdin-read-line)]
(if (nil? line)
reader-eof
(do (swap! stdin-buf (fn [b] (str b line "\n"))) (recur))))
(do (reset! stdin-buf (nth r 1)) (nth r 0))))))})
(defn read-line
"Reads the next line from the stream that is the current value of *in*.
Returns nil at EOF."
[]
((:read-line-fn *in*)))
(defn read
"Reads the next object from stream (defaults to *in*). At EOF, throws —
or returns eof-value when eof-error? is false."
([] (read *in*))
([stream]
(let [v ((:read-fn stream))]
(if (= v reader-eof)
(throw (ex-info "EOF while reading" {}))
v)))
([stream eof-error? eof-value]
(let [v ((:read-fn stream))]
(if (= v reader-eof)
(if eof-error? (throw (ex-info "EOF while reading" {})) eof-value)
v))))
(defmacro with-in-str
"Evaluates body with *in* bound to a fresh reader over string s."
[s & body]
`(binding [*in* (__string-reader ~s)]
~@body))
;; Like read, and also returns the exact text consumed for the form (leading
;; whitespace included). On EOF: throws, or returns [eof-value ""] when
;; eof-error? is false.
(defn read+string
([] (read+string *in*))
([stream] (read+string stream true nil))
([stream eof-error? eof-value]
(let [buf (get stream :buf)
fill (get stream :fill-fn)]
(loop []
(let [s (deref buf)
r (__parse-next s)]
(if (nil? r)
(if (and fill (fill))
(recur)
(if eof-error?
(throw (ex-info "EOF while reading" {}))
[eof-value ""]))
(do (reset! buf (nth r 1))
[(nth r 0) (subs s 0 (- (count s) (count (nth r 1))))])))))))
(defn line-seq
"Returns the lines of text from rdr as a lazy sequence of strings, as by
read-line. (Jolt extension kept from the old kernel stub: a plain string
splits into its lines.)"
[rdr]
(if (string? rdr)
(seq (str-split "\n" rdr))
(lazy-seq
(let [line ((:read-line-fn rdr))]
(when line
(cons line (line-seq rdr)))))))