Back
binding (clj)
(source)macro
(binding bindings & body)
binding => var-symbol init-expr
Creates new bindings for the (already-existing) vars, with the
supplied initial values, executes the exprs in an implicit do, then
re-establishes the bindings that existed before. The new bindings
are made in parallel (unlike let); all init-exprs are evaluated
before the vars are bound to their new values.
Examples
clojure
(deftest division
(is (= clojure.core// /))
(binding [*ns* *ns*]
(eval '(do (ns foo
(:require [clojure.core :as bar])
(:use [clojure.test]))
(is (= clojure.core// bar//))))))
(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]")))
(defn roundtrip
"Print an object and read it back. Returns rather than throws
any exceptions."
[o]
(binding [*print-length* nil
*print-dup* nil
*print-level* nil]
(try
(-> o pr-str read-string)
(catch Throwable t t))))
(defn roundtrip-dup
"Print an object with print-dup and read it back.
Returns rather than throws any exceptions."
[o]
(binding [*print-length* nil
*print-dup* true
*print-level* nil]
(try
(-> o pr-str read-string)
(catch Throwable t t))))
(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})))
penpot/penpot
#_:clj-kondo/ignore
(ns app.common.data.macros
"Data retrieval & manipulation specific macros."
(:refer-clojure :exclude [get-in select-keys str with-open min max])
#?(:cljs (:require-macros [app.common.data.macros]))
(:require
#?(:clj [clojure.core :as c]
:cljs [cljs.core :as c])
[app.common.data :as d]
[cljs.analyzer.api :as aapi]
[cuerdas.core :as str]))
(defmacro with-open
[bindings & body]
{:pre [(vector? bindings)
(even? (count bindings))
(pos? (count bindings))]}
(reduce (fn [acc bindings]
`(let ~(vec bindings)
(try
~acc
(finally
(d/close! ~(first bindings))))))
`(do ~@body)
(reverse (partition 2 bindings))))
:else
(str "expr assert: " (pr-str expr)))]
(when *assert*
`(binding [*assert-context* ~hint]
(when-not ~expr
(let [hint# ~hint
params# {:type :assertion
:code :expr-validation
:hint hint#}]
(throw (ex-info hint# params#)))))))))
:else
(str "expr assert: " (pr-str expr)))]
`(binding [*assert-context* ~hint]
(when-not ~expr
(let [hint# ~hint
params# {:type :assertion
:code :expr-validation
:hint hint#}]
(throw (ex-info hint# params#))))))))
pedestal/pedestal
(ns io.pedestal.interceptor.error
(:require [io.pedestal.interceptor :as interceptor]
[clojure.core.match :as match]))
`:exception-type` is a keyword of the exception's type, for example,
`:java.lang.ArithmeticException
"
[binding-vector & match-forms]
`(io.pedestal.interceptor/interceptor
{:error (fn ~binding-vector
(clojure.core.match/match [(ex-data ~(second binding-vector))]
~@match-forms))}))
hoplon/hoplon
(ns hoplon.binding
(:refer-clojure :exclude [binding bound-fn])
(:require [clojure.core :as clj]
[cljs.analyzer :as a]))
(defmacro binding
"See clojure.core/binding."
[bindings & body]
(let [env (assoc &env :ns (a/get-namespace a/*cljs-ns*))
value-exprs (take-nth 2 (rest bindings))
bind-syms (map #(:name (a/resolve-existing-var env %)) (take-nth 2 bindings))
bind-syms' (map (partial list 'quote) bind-syms)
set-syms (repeatedly (count bind-syms) gensym)
setfn (fn [x y]
{:push! `(fn []
(let [z# ~x]
(set! ~x ~y)
(fn [] (set! ~x z#))))})
thunkmaps (map setfn bind-syms set-syms)]
(a/confirm-bindings env bind-syms)
`(let [~@(interleave set-syms value-exprs)]
(hoplon.binding/push-thread-bindings ~(zipmap bind-syms' thunkmaps))
(try ~@body (finally (hoplon.binding/pop-thread-bindings))))))
(defmacro bound-fn
"See clojure.core/bound-fn."
[args & body]
`(hoplon.binding/bound-fn* (fn [~@args] ~@body)))
mikera/core.matrix
(ns clojure.core.matrix.macros-clj
"Namespace for core.matrix macros. Keeping them separate allows us to do conditional
macros that can handle the differences between Clojure and Clojurescript."
(:require [clojure.core.matrix.macros :refer [TODO c-for]])
(:import [java.util Arrays]))
(defmacro try-current-implementation
[sym form]
`(if clojure.core.matrix.impl.defaults/*trying-current-implementation*
(TODO (str "Not yet implemented: " ~(str form) " for " (class ~sym)))
(binding [clojure.core.matrix.impl.defaults/*trying-current-implementation* true]
(let [imp# (imp/get-canonical-object)
~sym (mp/coerce-param imp# ~sym)]
~form))))
mikera/core.matrix
(ns clojure.core.matrix.macros-cljs
"Namespace for core.matrix macros. Keeping them separate allows us to do conditional
macros that can handle the differences between Clojure and Clojurescript."
(:require [clojure.core.matrix.macros :refer [c-for TODO]]))
(defmacro try-current-implementation
[sym form]
`(if clojure.core.matrix.impl.defaults/*trying-current-implementation*
;(TODO (str "Not yet implemented: " ~(str form) " for " (type ~sym)))
(binding [clojure.core.matrix.impl.defaults/*trying-current-implementation* true]
(let [imp# (imp/get-canonical-object)
~sym (mp/coerce-param imp# ~sym)]
~form))))