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reader (clj)
(source)function
(reader x & opts)
Attempts to coerce its argument into an open java.io.Reader.
Default implementations always return a java.io.BufferedReader.
Default implementations are provided for Reader, BufferedReader,
InputStream, File, URI, URL, Socket, byte arrays, character arrays,
and String.
If argument is a String, it tries to resolve it first as a URI, then
as a local file name. URIs with a 'file' protocol are converted to
local file names.
Should be used inside with-open to ensure the Reader is properly
closed.
Examples
clojure
(deftest t-line-column-numbers
(let [code "(ns reader-metadata-test
(:require [clojure.java.io
:refer (resource reader)]))
(deftest Instants
(testing "Instants are read as java.util.Date by default"
(is (= java.util.Date (class #inst "2010-11-12T13:14:15.666"))))
(let [s "#inst \"2010-11-12T13:14:15.666-06:00\""]
(binding [*data-readers* {'inst read-instant-date}]
(testing "read-instant-date produces java.util.Date"
(is (= java.util.Date (class (read-string s)))))
(testing "java.util.Date instants round-trips"
(is (= (-> s read-string)
(-> s read-string pr-str read-string))))
(testing "java.util.Date instants round-trip throughout the year"
(doseq [month (range 1 13) day (range 1 29) hour (range 1 23)]
(let [s (format "#inst \"2010-%02d-%02dT%02d:14:15.666-06:00\"" month day hour)]
(is (= (-> s read-string)
(-> s read-string pr-str read-string))))))
(testing "java.util.Date handling DST in time zones"
(let [dtz (TimeZone/getDefault)]
(try
;; A timezone with DST in effect during 2010-11-12
(TimeZone/setDefault (TimeZone/getTimeZone "Australia/Sydney"))
(is (= (-> s read-string)
(-> s read-string pr-str read-string)))
(finally (TimeZone/setDefault dtz)))))
(testing "java.util.Date should always print in UTC"
(let [d (read-string s)
pstr (print-str d)
len (.length pstr)]
(is (= (subs pstr (- len 7)) "-00:00\"")))))
(binding [*data-readers* {'inst read-instant-calendar}]
(testing "read-instant-calendar produces java.util.Calendar"
(is (instance? java.util.Calendar (read-string s))))
(testing "java.util.Calendar round-trips"
(is (= (-> s read-string)
(-> s read-string pr-str read-string))))
(testing "java.util.Calendar remembers timezone in literal"
(is (= "#inst \"2010-11-12T13:14:15.666-06:00\""
(-> s read-string pr-str)))
(is (= (-> s read-string)
(-> s read-string pr-str read-string))))
(testing "java.util.Calendar preserves milliseconds"
(is (= 666 (-> s read-string
(.get java.util.Calendar/MILLISECOND)))))))
(let [s "#inst \"2010-11-12T13:14:15.123456789\""
s2 "#inst \"2010-11-12T13:14:15.123\""
s3 "#inst \"2010-11-12T13:14:15.123456789123\""]
(binding [*data-readers* {'inst read-instant-timestamp}]
(testing "read-instant-timestamp produces java.sql.Timestamp"
(is (= java.sql.Timestamp (class (read-string s)))))
(testing "java.sql.Timestamp preserves nanoseconds"
(is (= 123456789 (-> s read-string .getNanos)))
(is (= 123456789 (-> s read-string pr-str read-string .getNanos)))
;; truncate at nanos for s3
(is (= 123456789 (-> s3 read-string pr-str read-string .getNanos))))
(testing "java.sql.Timestamp should compare nanos"
(is (= (read-string s) (read-string s3)))
(is (not= (read-string s) (read-string s2)))))
(binding [*data-readers* {'inst read-instant-date}]
(testing "read-instant-date should truncate at milliseconds"
(is (= (read-string s) (read-string s2) (read-string s3))))))
(let [s "#inst \"2010-11-12T03:14:15.123+05:00\""
s2 "#inst \"2010-11-11T22:14:15.123Z\""]
(binding [*data-readers* {'inst read-instant-date}]
(testing "read-instant-date should convert to UTC"
(is (= (read-string s) (read-string s2)))))
(binding [*data-readers* {'inst read-instant-timestamp}]
(testing "read-instant-timestamp should convert to UTC"
(is (= (read-string s) (read-string s2)))))
(binding [*data-readers* {'inst read-instant-calendar}]
(testing "read-instant-calendar should preserve timezone"
(is (not= (read-string s) (read-string s2)))))))
(deftest unknown-tag
(let [my-unknown (fn [tag val] {:unknown-tag tag :value val})
throw-on-unknown (fn [tag val] (throw (RuntimeException. (str "No data reader function for tag " tag))))
my-uuid (partial my-unknown 'uuid)
u "#uuid \"550e8400-e29b-41d4-a716-446655440000\""
s "#never.heard.of/some-tag [1 2]" ]
(binding [*data-readers* {'uuid my-uuid}
*default-data-reader-fn* my-unknown]
(testing "Unknown tag"
(is (= (read-string s)
{:unknown-tag 'never.heard.of/some-tag
:value [1 2]})))
(testing "Override uuid tag"
(is (= (read-string u)
{:unknown-tag 'uuid
:value "550e8400-e29b-41d4-a716-446655440000"}))))
(binding [*default-data-reader-fn* throw-on-unknown]
(testing "Unknown tag with custom throw-on-unknown"
(are [err msg form] (thrown-with-msg? err msg (read-string form))
Exception #"No data reader function for tag foo" "#foo [1 2]"
Exception #"No data reader function for tag bar/foo" "#bar/foo [1 2]"
Exception #"No data reader function for tag bar.baz/foo" "#bar.baz/foo [1 2]")))
(testing "Unknown tag out-of-the-box behavior (like Clojure 1.4)"
(are [err msg form] (thrown-with-msg? err msg (read-string form))
Exception #"No reader function for tag foo" "#foo [1 2]"
Exception #"No reader function for tag bar/foo" "#bar/foo [1 2]"
Exception #"No reader function for tag bar.baz/foo" "#bar.baz/foo [1 2]"))))
(deftest preserve-read-cond-test
(let [x (read-string {:read-cond :preserve} "#?(:clj foo :cljs bar)" )]
(is (reader-conditional? x))
(is (not (:splicing? x)))
(is (= :foo (get x :no-such-key :foo)))
(is (= (:form x) '(:clj foo :cljs bar)))
(is (= x (reader-conditional '(:clj foo :cljs bar) false))))
(let [x (read-string {:read-cond :preserve} "#?@(:clj [foo])" )]
(is (reader-conditional? x))
(is (:splicing? x))
(is (= :foo (get x :no-such-key :foo)))
(is (= (:form x) '(:clj [foo])))
(is (= x (reader-conditional '(:clj [foo]) true))))
(is (thrown-with-msg? RuntimeException #"No reader function for tag"
(read-string {:read-cond :preserve} "#js {:x 1 :y 2}" )))
(let [x (read-string {:read-cond :preserve} "#?(:cljs #js {:x 1 :y 2})")
[platform tl] (:form x)]
(is (reader-conditional? x))
(is (tagged-literal? tl))
(is (= 'js (:tag tl)))
(is (= {:x 1 :y 2} (:form tl)))
(is (= :foo (get tl :no-such-key :foo)))
(is (= tl (tagged-literal 'js {:x 1 :y 2}))))
(testing "print form roundtrips"
(doseq [s ["#?(:clj foo :cljs bar)"
"#?(:cljs #js {:x 1, :y 2})"
"#?(:clj #clojure.test_clojure.reader.TestRecord [42 85])"]]
(is (= s (pr-str (read-string {:read-cond :preserve} s)))))))
(deftest reader-conditionals
(testing "basic read-cond"
(is (= '[foo-form]
(read-string {:read-cond :allow :features #{:foo}} "[#?(:foo foo-form :bar bar-form)]")))
(is (= '[bar-form]
(read-string {:read-cond :allow :features #{:bar}} "[#?(:foo foo-form :bar bar-form)]")))
(is (= '[foo-form]
(read-string {:read-cond :allow :features #{:foo :bar}} "[#?(:foo foo-form :bar bar-form)]")))
(is (= '[]
(read-string {:read-cond :allow :features #{:baz}} "[#?( :foo foo-form :bar bar-form)]"))))
(testing "environmental features"
(is (= "clojure" #?(:clj "clojure" :cljs "clojurescript" :default "default"))))
(testing "default features"
(is (= "default" #?(:clj-clr "clr" :cljs "cljs" :default "default"))))
(testing "splicing"
(is (= [] [#?@(:clj [])]))
(is (= [:a] [#?@(:clj [:a])]))
(is (= [:a :b] [#?@(:clj [:a :b])]))
(is (= [:a :b :c] [#?@(:clj [:a :b :c])]))
(is (= [:a :b :c] [#?@(:clj [:a :b :c])])))
(testing "nested splicing"
(is (= [:a :b :c :d :e]
[#?@(:clj [:a #?@(:clj [:b #?@(:clj [:c]) :d]):e])]))
(is (= '(+ 1 (+ 2 3))
'(+ #?@(:clj [1 (+ #?@(:clj [2 3]))]))))
(is (= '(+ (+ 2 3) 1)
'(+ #?@(:clj [(+ #?@(:clj [2 3])) 1]))))
(is (= [:a [:b [:c] :d] :e]
[#?@(:clj [:a [#?@(:clj [:b #?@(:clj [[:c]]) :d])] :e])])))
(testing "bypass unknown tagged literals"
(is (= [1 2 3] #?(:cljs #js [1 2 3] :clj [1 2 3])))
(is (= :clojure #?(:foo #some.nonexistent.Record {:x 1} :clj :clojure))))
(testing "error cases"
(is (thrown-with-msg? RuntimeException #"Feature should be a keyword" (read-string {:read-cond :allow} "#?((+ 1 2) :a)")))
(is (thrown-with-msg? RuntimeException #"even number of forms" (read-string {:read-cond :allow} "#?(:cljs :a :clj)")))
(is (thrown-with-msg? RuntimeException #"read-cond-splicing must implement" (read-string {:read-cond :allow} "#?@(:clj :a)")))
(is (thrown-with-msg? RuntimeException #"is reserved" (read-string {:read-cond :allow} "#?@(:foo :a :else :b)")))
(is (thrown-with-msg? RuntimeException #"must be a list" (read-string {:read-cond :allow} "#?[:foo :a :else :b]")))
(is (thrown-with-msg? RuntimeException #"Conditional read not allowed" (read-string {:read-cond :BOGUS} "#?[:clj :a :default nil]")))
(is (thrown-with-msg? RuntimeException #"Conditional read not allowed" (read-string "#?[:clj :a :default nil]")))
(is (thrown-with-msg? RuntimeException #"Reader conditional splicing not allowed at the top level" (read-string {:read-cond :allow} "#?@(:clj [1 2])")))
(is (thrown-with-msg? RuntimeException #"Reader conditional splicing not allowed at the top level" (read-string {:read-cond :allow} "#?@(:clj [1])")))
(is (thrown-with-msg? RuntimeException #"Reader conditional splicing not allowed at the top level" (read-string {:read-cond :allow} "#?@(:clj []) 1"))))
(testing "clj-1698-regression"
(let [opts {:features #{:clj} :read-cond :allow}]
(is (= 1 (read-string opts "#?(:cljs {'a 1 'b 2} :clj 1)")))
(is (= 1 (read-string opts "#?(:cljs (let [{{b :b} :a {d :d} :c} {}]) :clj 1)")))
(is (= '(def m {}) (read-string opts "(def m #?(:cljs ^{:a :b} {} :clj ^{:a :b} {}))")))
(is (= '(def m {}) (read-string opts "(def m #?(:cljs ^{:a :b} {} :clj ^{:a :b} {}))")))
(is (= 1 (read-string opts "#?(:cljs {:a #_:b :c} :clj 1)")))))
(testing "nil expressions"
(is (nil? #?(:default nil)))
(is (nil? #?(:foo :bar :clj nil)))
(is (nil? #?(:clj nil :foo :bar)))
(is (nil? #?(:foo :bar :default nil)))))
(require '[clojure.string :as s])
(deftest namespaced-maps
(is (= #:a{1 nil, :b nil, :b/c nil, :_/d nil}
#:a {1 nil, :b nil, :b/c nil, :_/d nil}
{1 nil, :a/b nil, :b/c nil, :d nil}))
(is (= #::{1 nil, :a nil, :a/b nil, :_/d nil}
#:: {1 nil, :a nil, :a/b nil, :_/d nil}
{1 nil, :clojure.test-clojure.reader/a nil, :a/b nil, :d nil} ))
(is (= #::s{1 nil, :a nil, :a/b nil, :_/d nil}
#::s {1 nil, :a nil, :a/b nil, :_/d nil}
{1 nil, :clojure.string/a nil, :a/b nil, :d nil}))
(is (= (read-string "#:a{b 1 b/c 2}") {'a/b 1, 'b/c 2}))
(is (= (binding [*ns* (the-ns 'clojure.test-clojure.reader)] (read-string "#::{b 1, b/c 2, _/d 3}")) {'clojure.test-clojure.reader/b 1, 'b/c 2, 'd 3}))
(is (= (binding [*ns* (the-ns 'clojure.test-clojure.reader)] (read-string "#::s{b 1, b/c 2, _/d 3}")) {'clojure.string/b 1, 'b/c 2, 'd 3})))
djblue/portal
(require '[babashka.deps :as deps])
(require '[clojure.java.io :as io])
(require '[cheshire.core :as json])
(doseq [line (line-seq (io/reader *in*))]
(tap>
(try
(json/parse-string line true)
(catch Exception _ex
line))))
acmeism/RosettaCodeData
(require '[clojure.java.io :as io])
(def groups
(with-open [r (io/reader wordfile)]
(group-by sort (line-seq r))))
metosin/muuntaja
(ns muuntaja.protocols
(:require [clojure.java.io :as io]
[muuntaja.util :as util])
(:import (clojure.lang IFn AFn)
(java.io ByteArrayOutputStream ByteArrayInputStream InputStreamReader BufferedReader InputStream Writer OutputStream FileInputStream File)))
(extend StreamableResponse
io/IOFactory
(assoc io/default-streams-impl
:make-input-stream (fn [^StreamableResponse this _]
(with-open [out (ByteArrayOutputStream. 4096)]
((.f this) out)
(ByteArrayInputStream.
(.toByteArray out))))
:make-reader (fn [^StreamableResponse this _]
(with-open [out (ByteArrayOutputStream. 4096)]
((.f this) out)
(BufferedReader.
(InputStreamReader.
(ByteArrayInputStream.
(.toByteArray out))))))))
swannodette/cljs-bootstrap
(ns dotdot
(:require [clojure.java.io :as io]
[cljs.env :as env]
[cljs.analyzer :as ana]
[cljs.compiler :as comp]
[cljs.closure :as closure]
[cljs.tagged-literals :as tags]
[clojure.tools.reader :as r]
[clojure.tools.reader.reader-types :refer [string-push-back-reader]]))
;; ~42ms on work machine
(time
(let [rdr (string-push-back-reader f)
eof (Object.)]
(binding [*ns* (create-ns 'cljs.analyzer)
r/*data-readers* tags/*cljs-data-readers*]
(loop []
(let [x (r/read {:eof eof} rdr)]
(when-not (identical? eof x)
(recur)))))))
;; 2.2s
(dotimes [_ 10]
(time
(env/ensure
(closure/compile-form-seq
(ana/forms-seq*
(io/reader (io/resource "cljs/core.cljs")))))))
)
jackrusher/mundaneum
(ns mundaneum.properties
(:require [clojure.java.io :as io]
[clojure.string :as string]
[clojure.data.json :as json]))
;; Properties fetched using the wikibase command line tool:
;; https://github.com/maxlath/wikibase-cli
;; ... example invocations:
;; $ wb props > props-2021-11-04.json
;; (or via Docker):
;; $ docker run --rm -it maxlath/wikibase-cli props -e https://query.wikidata.org/sparql >props-2023-05-08.json
(def wdt
(->> (json/read (io/reader (io/resource "props-2023-05-08.json")))
(reduce (fn [m [id text]]
(assoc m
(-> text
(string/replace #"[ /]" "-")
(string/replace #"[\(\)\'\,;\"]" "")
keyword)
(keyword (str "wdt/" id))))
{})))