Because XML external entity (XXE) attacks can be used to disclose local files using file schemes or relative paths in the system identifier, clojure.xml/parse
now disables external entity processing by default.
See: https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing
This change disables the following SAX parser features:
http://apache.org/xml/features/nonvalidating/load-external-dtd
http://xml.org/sax/features/external-general-entities
http://xml.org/sax/features/external-parameter-entities
If you rely on these features, modify your calls to clojure.xml/parse
to explicitly
supply startparse-sax
function as the final argument:
(clojure.xml/parse the-string clojure.xml/startparse-sax)
This modification also works on prior Clojure versions.
Updated dependencies:
Keyword arguments are optional trailing variadic arguments of the form akey aval bkey bval....
In Clojure 1.11, functions taking keyword arguments can now be passed a map instead of or in addition
to and following the key/value pairs. When a lone map is passed, it is used for destructuring, else
a trailing map is added to the key/value pair map by conj
.
Also see: https://clojure.org/news/2021/03/18/apis-serving-people-and-programs
:as-alias
in require
Spec (and other libs) rely on qualified keywords as spec names.
Namespace aliasing in ns
makes long names shorter but required namespaces to be loadable.
This change adds :as-alias
to require
, which is like :as
but does not require the namespace to load.
Added a new clojure.math namespace which provides wrappers for the functions available in java.lang.Math.
These functions are narrowed to only long
and double
overloads and provide primitive support without reflection.
In addition, the following functions were added to clojure.core:
abs
- absolute value in optimized form for all Clojure numeric types (long, double, ratio, bigint, bigdecimal)
NaN?
- predicate for doubles to check whether "not a number"
infinite?
- predicate for doubles to check whether positive or negative infinity
CLJ-2668 Add NaN? and infinite? predicates
CLJ-2664 Add clojure.java.math namespace, wrappers for java.lang.Math
CLJ-2673 Add abs
, and update min
and max
to use Math impls when possible
CLJ-2677 clojure.math - fix method reflection in bodies and inlines, fix docstrings, renamed
CLJ-2689 Fix clojure.math tests to be more tolerant of floating point comparisons
Added the following parsing functions to clojure.core:
parse-double
- parses floating point number, including scientific notationparse-long
- parses integer in long rangeparse-boolean
- parses "true"
or "false"
to the canonical boolean valuesparse-uuid
- parses a UUID string to java.util.UUIDAll of these functions expect a string argument and return either the parsed value or nil
if the value
is in invalid format.
random-uuid
Added random-uuid
, a function to construct a random java.util.UUID.
update-keys
and update-vals
Added:
update-keys
- applies a function to every key in a map, m f => {(f k) v ...}
update-vals
- applies a function to every value in a map, m f => {k (f v) ...}
CLJ-1959 Add implementation of update-keys
CLJ-2651 Add implementation of update-vals
iteration
Added iteration
, to repeatedly apply a (possibly impure) step function with continuation state.
This can be used e.g. to consume APIs that return paginated or batched data.
iteration
generator functioniteration
docstring and arg namesiteration
generative test failuredefprotocol
=
not terminating when called with infinite sequencecase
expressions on symbolsrealized?
of delay
on pending resultsome-fn
and every-pred
for 3 predicate case to match other unrollingsinto
completion so halt-when
worksmap-invert
should use reduce-kv
and transient*clojure-version*
Compiler.load()
get
docstring regarding sets, strings, arrays, ILookupreify
docstringclojure.string/split
docstring regarding trailing empty partstest-vars
docstringbrowse-url
hanging on call to xdg-openrun-test
and run-test-var
to run single test with fixtures and report:actual
form in :pass
maps:exception
:val
s in prepl
Updated dependencies:
*print-meta*
is trueRecent builds of Java 8 (u202), 11 (11.0.2), 12, and 13 included some changes that drastically affect optimization performance of calls from static initializers to static fields. Clojure provides support for loading code on startup from a user.clj file and this occurred in the static initializer of the Clojure runtime (RT) class and was thus affected.
This issue may eventually be resolved in Java, but in Clojure we have modified runtime initialization to avoid loading user.clj in a static initializer, which mitigates the case where this caused a performance degradation.
clojure.main is frequently used as a Clojure program launcher by external tools. Previously, uncaught exceptions would be automatically printed by the JVM, which would also print the stack trace.
This release will now catch exceptions and use the same error triage and printing functionality as the Clojure repl. The full stack trace, ex-info, and other information will be printed to a target specified by the configuration.
The three available error targets are:
These error targets can be specified either as options to clojure.main, or as
Java system properties (flags take precedence). When invoking clojure.main
(or using the clj tool), use --report <target>
. For Java system property,
use -Dclojure.main.report=<target>
.
Clojure 1.10 now requires Java 8 or above. There were a number of updates related to this change and/or Java compatibility fixes for Java 8, 9, 10, and 11:
Updated dependencies:
Clojure errors can occur in several distinct "phases" - reading source, macroexpansion, compilation, execution, and result printing. Clojure (and the REPL) now identify these phases in the exception and the message.
The read/macroexpand/compile phases produce a CompilerException and indicate the location in the caller source code where the problem occurred (previously macroexpansion reported the error in the macroexpansion stack). CompilerException now implements IExceptionInfo and ex-data will report exception data including the following (optional) keys:
clojure.main also contains two new functions: ex-triage
and ex-str
that can be used by external tools to mimic some or all of the Clojure repl reporting. ex-triage
takes the output of Throwable->map
and produces a concise analysis of the error phase, cause, etc (same keys as above). ex-str
takes that analysis data and produces a message to print at the repl.
ex-triage
, execution error line reportingdefprotocol
has a new option :extend-via-metadata
. When :extend-via-metadata is true, values can extend protocols by adding metadata where keys are fully-qualified protocol function symbols and values are function implementations. Protocol implementations are checked first for direct definitions (defrecord, deftype, reify), then metadata definitions, then external extensions (extend, extend-type, extend-protocol).
tap is a shared, globally accessible system for distributing a series of informational or diagnostic values to a set of (presumably effectful) handler functions. It can be used as a better debug prn, or for facilities like logging etc.
tap>
sends a value to the set of taps. Taps can be added with add-tap
and will be called with any value sent to tap>
. The tap function may (briefly) block (e.g. for streams) and will never impede calls to tap>
, but blocking indefinitely may cause tap values to be dropped. If no taps are registered, tap>
discards. Remove taps with remove-tap
.
read+string
is a new function that mimics read
but also captures the string that is read and returns both the read value and the (whitespace-trimmed) read string. read+string
requires a LineNumberingPushbackReader.
prepl is a new stream-based REPL with structured output (suitable for programmatic use). Forms are read from the reader, evaluated, and return data maps for the return value (if successful), output to *out*
(possibly many), output to *err*
(possibly many), or tap> values (possibly many).
New functions in clojure.core.server:
prepl
- the replio-prepl
- a prepl bound to *in*
and *out*
suitable for use with the Clojure socket serverremote-prepl
- a prepl that can be connected to a remote prepl over a socketprepl is alpha and subject to change.
clojure.datafy is a facility for object to data transformation. The datafy
and nav
functions can be used used to transform and (lazily) navigate through object graphs. The data transformation process can be influenced by consumers using protocols or metadata.
datafy is alpha and subject to change.
These functions have been added to match existing functions in ClojureScript to increase the portability of error-handling code:
ex-cause
- extract the cause exceptionex-message
- extract the cause messageThis function has been added to construct a PrintWriter implementation whose behavior on flush and close is provided as functions:
PrintWriter-on
- create a PrintWriter from flush-fn and close-fnThe following function has been added, extending resolve
:
requiring-resolve
- resolve or, if needed, require symbol's namespace, then resolveserialized-require
- like require
but for use in asynchronous load usesproxy
- fix typoremove-tap
- fix repetitionflatten
- describe result as lazysome
with-meta
should return identity when new meta is identical to priorsymbol
can now take a var or a keyword argumentsort
and sort-by
should retain metawithout
spec is a new core library for describing, validating, and testing the structure of data and functions.
For more information, see:
Note that spec is in alpha state and API compatibility is not guaranteed. Also, spec and the specs for the Clojure core API are distributed as external libraries that must be included to use Clojure.
Several enhancements have been made to add support for working with maps with qualified keys:
#:car{:make "Jeep" :model "Wrangler"}
. For more information see https://clojure.org/reference/reader#_maps (CLJ-1910)*print-namespace-maps*
- by default maps will not print with the map namespace syntax except in the clojure.main repl. This dynamic var is a flag to allow you to control whether the namespace map syntax is used.Specs rely heavily on predicates and many new type and value oriented predicates have been added to clojure.core:
boolean?
int?
pos-int?
neg-int?
nat-int?
double?
ident?
simple-ident?
qualified-ident?
simple-symbol?
qualified-symbol?
simple-keyword?
qualified-keyword?
bytes?
(for byte[]
)indexed?
uuid?
uri?
seqable?
any?
More support has been added for the notion of instants in time:
Inst
for instant typesInst
is extended for java.util.Date
Inst
is optionally extended for java.time.Instant
in Java 1.8+inst?
, inst-ms
These are some other new functions in clojure.core:
bounded-count
- a count that avoids realizing the entire collection beyond a boundswap-vals!
and reset-vals!
- new atom functions that return both the old and new values (CLJ-1454)halt-when
- new transducer that ends transduction when pred is satisfied*reader-resolver*
to an impl of LispReader$Resolver to control the reader’s use of namespace interactions when resolving autoresolved keywords and maps.If a macro has a spec defined via fdef, that spec will be checked at compile time. Specs have been defined for many clojure.core macros and errors will be reported for these based on the specs at compile time.
doc
will now report specs for functions with specs defined using fdef
doc
can now be invoked with a fully-qualified keyword representing a spec nameslurp
- mark return type as Stringclojure.core/delay
- improve performanceamap
- should call alength only oncemin-key
and max-key
- evaluate k on each arg at most onceinto
now has a 0-arity (returns []
) and 1-arity (returns the coll that's passed)clojure.repl/dir-fn
now works on namespace aliasesclojure.java.io/copy
- doc char[] supportclojure.pprint
docstring - fix typoclojure.instant/validated
docstring - fix typodeftype
- fix typo in docstringfilter
, filterv
, remove
, take-while
- fix docstringsawait
- improve docstring re shutdown-agents
require
, *data-readers*
- add .cljc files to docstringszero?
, pos?
, neg?
- fix docstringsindex-of
, last-index-of
- clarify docstringsdrop-last
- fix docstringclojure.java.io/delete-file
- improve docstringclojure.core/Throwable->map
formerly returned StackTraceElement
s which were later handled by the printer. Now the StackTraceElements are converted to data such that the return value is pure Clojure data, as intended.clojure.lang.APersistentVector#hashCode
is not thread-saferange
realizationIPersistentVector.length()
- implement missing methoddefmulti
removes metadata on the varbean
- iterator was brokenvector-of
- fix NullPointerException if given unrecognized typeclojure.java.javadoc/javadoc
- update doc urlsNumbers.divide(Object, Object)
- add checks for NaNdoc
- does not expand special cases properly (try, catch)contains?
, get
, and find
broken for transient collectionsDirect linking can be enabled with -Dclojure.compiler.direct-linking=true
Direct linking allows functions compiled with direct linking on to make direct static method calls to most other functions, instead of going through the var and the Fn object. This can enable further optimization by the jit, at a cost in dynamism. In particular, directly-linked calls will not see redefinitions.
With this change, clojure.core itself is compiled with direct linking and therefore other namespaces cannot redefine core fns and have those redefinitions seen by core code.
A new metadata key ^:redef is provided. A function declared with this key can be redefined and will never be direct linked. Also, functions declared as ^:dynamic will never be direct linked.
Several new string functions were added to clojure.string to increase portability and reduce the need for Java interop calls:
index-of - search for the index of a char or string in a string
last-index-of - search for the index of a char or string backwards in a string
starts-with? - true if string starts with a substring
ends-with? - true if string ends with a substring
includes? - true if string includes a substring
The Clojure runtime now has the ability to start a socket server at initialization based on system properties. One expected use for this is serving a socket-based REPL, but it also has many other potential uses for dynamically adding server capability to existing programs without code changes.
A socket server will be started for each JVM system property like
clojure.server.<server-name>
. The value for this property is an edn map
representing the configuration of the socket server with the following properties:
*err*
to socket out streamAdditionally, there is a repl function provided that is slightly customized for
use with the socket server in clojure.core.server/repl
.
Following is an example of starting a socket server with a repl listener. This can be added to any existing Clojure program to allow it to accept external REPL clients.
-Dclojure.server.repl="{:port 5555 :accept clojure.core.server/repl}"
An example client you can use to connect to this socket repl is telnet:
$ telnet 127.0.0.1 5555
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
user=> (println "hello")
hello
See:
are
and anon fn
Please be aware of the following issues when upgrading to Clojure 1.7.
Seqs are fundamentally incompatible with Java iterators that return the same mutating object on every call to next(). Some Clojure libraries incorrectly rely on calling seq on such iterators.
In 1.7, iterator-seqs are chunked, which will cause many of these incorrect usages to return incorrect results immediately.
The seq
and iterator-seq
docstrings have been updated to include
an explicit warning. Libraries that incorrectly use seq
and
iterator-seq
will need to be fixed before running against 1.7.
Prior to Clojure 1.7, transients would allow modification only from the thread that created the transient. This check has been removed. It is still a requirement that transients should be updated by only a single thread at a time.
This constraint was relaxed to allow transients to be used in cases where code is multiplexed across multiple threads in a pool (such as go blocks in core.async).
Invoking keys
or vals
on a custom map type that implements IPersistentMap
will now use the Iterable iterator() method instead of accessing entries
via the seq of the map. There have been no changes in the type hierarchy
(IPersistentMap has always extended Iterable) but former map-like instances
may have skipped implementing this method in the past.
Transducers is a new way to decouple algorithmic transformations from their application in different contexts. Transducers are functions that transform reducing functions to build up a "recipe" for transformation.
Also see: http://clojure.org/transducers
Many existing sequence functions now have a new arity (one fewer argument than before). This arity will return a transducer that represents the same logic but is independent of lazy sequence processing. Functions included are:
Additionally some new transducer functions have been added:
And this function can be used to make completing transforms:
There are also several new or modified functions that can be used to apply transducers in different ways:
There have been a number of internal changes to support transducers:
Some related issues addressed during development:
Reader Conditionals are a new capability to support portable code that can run on multiple Clojure platforms with only small changes. In particular, this feature aims to support the increasingly common case of libraries targeting both Clojure and ClojureScript.
Code intended to be common across multiple platforms should use a new supported file extension: ".cljc". When requested to load a namespace, the platform-specific file extension (.clj, .cljs) will be checked prior to .cljc.
A new reader form can be used to specify "reader conditional" code in cljc files (and only cljc files). Each platform defines a feature identifying the platform (:clj, :cljs, :cljr). The reader conditional specifies code that is read conditionally based on the feature. The REPL also allows reader conditionals.
Form #? takes a list of alternating feature and expression. These are
checked like cond and the selected expression is read and returned. Other
branches are read but skipped. If no branch is selected, the reader reads
nothing (not nil, but literally as if reading no form). An optional
:default
branch can be used as a fallthrough.
Reader conditional with 2 features and a default:
#?(:clj Double/NaN
:cljs js/NaN
:default nil)
There is also a reader conditional splicing form. The evaluated expression should be sequential and will be spliced into the surrounded code, similar to unquote-splicing.
For example:
[1 2 #?@(:clj [3 4] :cljs [5 6])]
This form would read as [1 2 3 4] on Clojure, [1 2 5 6] on ClojureScript, and [1 2] on any other platform. Splicing is not allowed at the top level.
Additionally, the reader can now be invoked with options for the features to use and how to interpret reader conditionals. By default, reader conditionals are not allowed, but that can be turned on, or a "preserve" mode can be used to preserve all branches (most likely useful for tooling or source transforms).
In the preserve mode, the reader conditional itself and any tagged literals within the unselected branches are returned as tagged literal data.
For more information, see: http://dev.clojure.org/display/design/Reader+Conditionals
In response to issues raised in CLJ-1439, several changes have been made in symbol and keyword construction:
The main bottleneck in construction of symbols (which also occurs inside keywords) was interning of the name and namespace strings. This interning has been removed, resulting in a performance increase.
Keywords are cached and keyword construction includes a cache check. A change was made to only clear the cache reference queue when there is a cache miss.
One source of performance issues is the (unintended) use of arithmetic operations on boxed numbers. To make detecting the presence of boxed math easier, a warning will now be emitted about boxed math if *unchecked-math* is set to :warn-on-boxed (any truthy value will enable unchecked-math, only this specific value enables the warning).
Example use:
user> (defn plus-2 [x] (+ x 2)) ;; no warning, but boxed
#'user/plus-2
user> (set! *unchecked-math* :warn-on-boxed)
true
user> (defn plus-2 [x] (+ x 2)) ;; now we see a warning
Boxed math warning, NO_SOURCE_PATH:10:18 - call: public static java.lang.Number
clojure.lang.Numbers.unchecked_add(java.lang.Object,long).
#'user/plus-2
user> (defn plus-2 [^long x] (+ x 2)) ;; use a hint to avoid boxing
#'user/plus-2
update
is a new function that is like update-in specifically for first-level keys:
(update m k f args...)
Example use:
user> (update {:a 1} :a inc)
{:a 2}
user> (update {:a 1} :a + 2)
{:a 3}
user> (update {} :a identity) ;; missing returns nil
{:a nil}
Several important Clojure functions now return sequences that also contain fast reduce() (or in some cases iterator()) paths. In many cases, the new implementations are also faster for lazy sequences
Additionally, hash-maps and hash-sets now provide iterators that walk the data structure directly rather than via a sequence.
A new interface (IMapIterable) for direct key and val iterators on maps was added. External data structures can use this interface to provide direct key and val iterators via keys and vals.
These enhancements are particularly effective when used in tandem with transducers via transduce, sequence, into, and eduction.
There have been enhancements in how the REPL prints values without a print-method, specifically Throwable and the fallthrough Object case. Both cases now print in a tagged literal data form that can be read by the reader.
Unhandled objects print with the class, hash code, and toString:
user=> *ns*
#object[clojure.lang.Namespace 0x55aa628 "user"]
Thrown exceptions will still be printed in the normal way by the default REPL but printing them to a stream will show a different form:
user=> (/ 1 0)
ArithmeticException Divide by zero clojure.lang.Numbers.divide (Numbers.java:158)
user=> (println *e)
#error {
:cause Divide by zero
:via
[{:type java.lang.ArithmeticException
:message Divide by zero
:at [clojure.lang.Numbers divide Numbers.java 158]}]
:trace
[[clojure.lang.Numbers divide Numbers.java 158]
[clojure.lang.Numbers divide Numbers.java 3808]
;; ... elided frames
]}
Additionally, there is a new function available to obtain a Throwable as
map data: Throwable->map
.
run! is a new function that takes a side effect reducing function and runs it for all items in a collection via reduce. The accumulator is ignored and nil is returned.
(run! println (range 10))
Clojure now builds with Java SE 1.6 and emits bytecode requiring Java SE 1.6 instead of Java SE 1.5. [CLJ-1268]
The embedded version of the ASM bytecode library has been upgraded to ASM 4.1. [CLJ-713]
The following features are no longer marked Alpha in Clojure:
The clojure.java.api package provides a minimal interface to bootstrap Clojure access from other JVM languages. It does this by providing:
IFns provide complete access to Clojure's APIs. You can also access any other library written in Clojure, after adding either its source or compiled form to the classpath.
The public Java API for Clojure consists of the following classes and interfaces:
All other Java classes should be treated as implementation details, and applications should avoid relying on them.
To look up and call a Clojure function:
IFn plus = Clojure.var("clojure.core", "+");
plus.invoke(1, 2);
Functions in clojure.core are automatically loaded. Other namespaces can be loaded via require:
IFn require = Clojure.var("clojure.core", "require");
require.invoke(Clojure.read("clojure.set"));
IFns can be passed to higher order functions, e.g. the example below passes plus to read:
IFn map = Clojure.var("clojure.core", "map");
IFn inc = Clojure.var("clojure.core", "inc");
map.invoke(inc, Clojure.read("[1 2 3]"));
Most IFns in Clojure refer to functions. A few, however, refer to non-function data values. To access these, use deref instead of fn:
IFn printLength = Clojure.var("clojure.core", "*print-length*");
Clojure.var("clojure.core", "deref").invoke(printLength);
In the past, map destructuring with :keys and :syms would not work with maps containing namespaced keys or symbols. The :keys and :syms forms have been updated to allow them to match namespaced keys and bind to a local variable based on the name.
Examples:
(let [m {:x/a 1, :y/b 2}
{:keys [x/a y/b]} m]
(+ a b))
(let [m {'x/a 1, 'y/b 2}
{:syms [x/a y/b]} m]
(+ a b))
Additionally, the :keys form can now take keywords instead of symbols. This provides support specifically for auto-resolved keywords:
(let [m {:x/a 1, :y/b 2}
{:keys [:x/a :y/b]} m]
(+ a b))
(let [m {::x 1}
{:keys [::x]} m]
x)
Many conditional functions rely on logical truth (where "falsey" values are nil or false). Sometimes it is useful to have functions that rely on "not nilness" instead. These functions have been added to support these cases [CLJ-1343]:
Clojure 1.6 provides new hashing algorithms for primitives and collections, accessible via IHashEq/hasheq (in Java) or the clojure.core/hash function (in Clojure). In general, these changes should be transparent to users, except hash codes used inside hashed collections like maps and sets will have better properties.
Hash codes returned by the Java .hashCode() method are unchanged and continue to match Java behavior or conform to the Java specification as appropriate.
Any collections implementing IHashEq or wishing to interoperate with
Clojure collections should conform to the hashing algorithms specified
in http://clojure.org/data_structures#hash and use the new function
mix-collection-hash
for the final mixing operation. Alternatively,
you may call the helper functions hash-ordered-coll
and
hash-unordered-coll
.
Any details of the current hashing algorithm not specified on that page should be considered subject to future change.
Related tickets for dev and regressions:
A new unsigned-bit-shift-right (Java's >>>) has been added to the core library. The shift distance is truncated to the least 6 bits (per the Java specification for long >>>).
Examples: (unsigned-bit-shift-right 2r100 1) ;; 2r010 (unsigned-bit-shift-right 2r100 2) ;; 2r001 (unsigned-bit-shift-right 2r100 3) ;; 2r000
Added a new clojure.test/test-vars function that takes a list of vars, groups them by namespace, and runs them with their fixtures.
1 Deprecated and Removed Features 1.1 Clojure 1.5 reducers library requires Java 6 or later 2 New and Improved Features 2.1 Reducers 2.2 Reader Literals improved 2.3 clojure.core/set-agent-send-executor!, set-agent-send-off-executor!, and send-via 2.4 New threading macros 2.5 Column metadata captured by reader 2.6 gen-class improvements 2.7 Support added for marker protocols 2.8 clojure.pprint/print-table output compatible with Emacs Org mode 2.9 clojure.string/replace and replace-first handle special characters more predictably 2.10 Set and map constructor functions allow duplicates 2.11 More functions preserve metadata 2.12 New edn reader, improvements to *read-eval* 3 Performance Enhancements 4 Improved error messages 5 Improved documentation strings 6 Bug Fixes 7 Binary Compatibility Notes
The new reducers library (see below) requires Java 6 plus a ForkJoin library, or Java 7 or later. Clojure 1.5 can still be compiled and run with Java 5. The only limitations with Java 5 are that the new reducers library will not work, and building Clojure requires skipping the test suite (e.g. by using the command "ant jar").
Reducers provide a set of high performance functions for working with collections. The actual fold/reduce algorithms are specified via the collection being reduced. This allows each collection to define the most efficient way to reduce its contents.
The implementation details of reducers are available at the Clojure blog and therefore won't be repeated in these change notes. However, as a summary:
Examples:
user=> (require '[clojure.core.reducers :as r])
user=> (reduce + (r/filter even? (r/map inc [1 1 1 2])))
;=> 6
;;red is a reducer awaiting a collection
user=> (def red (comp (r/filter even?) (r/map inc)))
user=> (reduce + (red [1 1 1 2]))
;=> 6
user=> (into #{} (r/filter even? (r/map inc [1 1 1 2])))
;=> #{2}
CLJ-1034 "Conflicting data-reader mapping" should no longer be thrown where there really isn't a conflict. Until this patch, having data_readers.clj on the classpath twice would cause the above exception.
CLJ-927
Added *default-data-reader-fn*
to clojure.core. When no data reader is found for a tag and *default-data-reader-fn*
is non-nil, it will be called with two arguments, the tag and the value. If *default-data-reader-fn*
is nil (the default), an exception will be thrown for the unknown tag.
Added two new functions:
clojure.core/set-agent-send-executor!
Allows the user to set the java.util.concurrent.Executor
used when calling clojure.core/send
. Defaults to a fixed thread pool of size: (numCores + 2)
clojure.core/set-agent-send-off-executor!
Allows the user to set the java.util.concurrent.Executor
used when calling clojure.core/send-off
. Defaults to a cached thread pool.
clojure.core/send-via
Like send
, and send-off
, except the first argument to this function is an executor to use when sending.
clojure.core/cond-> [expr & clauses]
Takes an expression and a set of test/form pairs. Threads the expression (via ->) through each form for which the corresponding test expression (not threaded) is true.
Example:
user=> (cond-> 1
true inc
false (* 42)
(= 2 2) (* 3))
6
clojure.core/cond->> [expr & clauses]
Takes an expression and a set of test/form pairs. Threads expr (via ->>) through each form for which the corresponding test expression (not threaded) is true.
Example:
user=> (def d [0 1 2 3])
#'user/d
user=> (cond->> d
true (map inc)
(seq? d) (map dec)
(= (count d) 4) (reduce +)) ;; no threading in the test expr
;; so d must be passed in explicitly
10
Binds name to expr, evaluates the first form in the lexical context of that binding, then binds name to that result, repeating for each successive form
Note: this form does not actually perform any threading. Instead it allows the user to assign a name and lexical context to a value created by a parent threading form.
Example:
user=> (-> 84
(/ 4)
(as-> twenty-one ;; uses the value from ->
(* 2 twenty-one))) ;; no threading here
42
When expr is not nil, threads it into the first form (via ->), and when that result is not nil, through the next etc.
Example:
user=> (defn die [x] (assert false))
#'user/die
user=> (-> 1 inc range next next next die)
AssertionError Assert failed: false user/die (NO_SOURCE_FILE:65)
user=> (some-> 1 inc range next next next die)
nil
clojure.core/some->> [expr & forms]
When expr is not nil, threads it into the first form (via ->>), and when that result is not nil, through the next etc.
Same as some-> except the value is threaded as the last argument in each form.
:exposes-methods
in gen-class
. This allows Clojure classes created via gen-class to access protected methods of its parent class.Example:
(gen-class :name clojure.test_clojure.genclass.examples.ProtectedFinalTester
:extends java.lang.ClassLoader
:main false
:prefix "pf-"
:exposes-methods {findSystemClass superFindSystemClass})
gen-class
.Example:
(gen-class :name foo.Bar
:extends clojure.lang.Box
:constructors {^{Deprecated true} [Object] [Object]}
:init init
:prefix "foo")
defprotocol
no longer requires that at least one method be given in the definition of the protocol. This allows for marker protocols, whose sole reason of existence is to allow satisfies?
to be true for a given type.Example:
user=> (defprotocol P (hi [_]))
P
user=> (defprotocol M) ; marker protocol
M
user=> (deftype T [a] M P (hi [_] "hi there"))
user.T
user=> (satisfies? P (T. 1))
true
user=> (satisfies? M (T. 1))
true
user=> (hi (T. 1))
"hi there"
user=> (defprotocol M2 "marker for 2") ; marker protocol again
M2
user=> (extend-type T M2)
nil
user=> (satisfies? M2 (T. 1))
true
For the convenience of those that use Emacs Org mode,
clojure.pprint/print-table
now prints tables in the form used by
that mode. Emacs Org mode has features to make it easy to edit such
tables, and even to do spreadsheet-like calculations on their
contents. See the Org mode documentation on
tables for details.
user=> (clojure.pprint/print-table [:name :initial-impression]
[{:name "Rich" :initial-impression "rock star"}
{:name "Andy" :initial-impression "engineer"}])
| :name | :initial-impression |
|-------+---------------------|
| Rich | rock star |
| Andy | engineer |
clojure.string/replace
and clojure.string/replace-first
are now
consistent in the way that they handle the replacement strings: all
characters in the replacement strings are treated literally, including
backslash and dollar sign characters.
user=> (require '[clojure.string :as s])
user=> (s/replace-first "munge.this" "." "$")
;=> "munge$this"
user=> (s/replace "/my/home/dir" #"/" (fn [s] "\\"))
;=> "\\my\\home\\dir"
There is one exception, which is described in the doc strings. If you
call these functions with a regex to search for and a string as the
replacement, then dollar sign and backslash characters in the
replacement string are treated specially. Occurrences of $1
in the
replacement string are replaced with the string that matched the first
parenthesized subexpression of the regex, occurrences of $2
are
replaced with the match of the second parenthesized subexpression,
etc.
user=> (s/replace "x12, b4" #"([a-z]+)([0-9]+)" "$1 <- $2")
;=> "x <- 12, b <- 4"
Individual occurrences of $
or \
in the replacement string that
you wish to be treated literally can be escaped by prefixing them with
a \
. If you wish your replacement string to be treated literally
and its contents are unknown to you at compile time (or you don't wish
to tarnish your constant string with lots of backslashes), you can use
the new function clojure.string/re-quote-replacement
to do the
necessary escaping of special characters for you.
user=> (s/replace "x12, b4" #"([a-z]+)([0-9]+)"
(s/re-quote-replacement "$1 <- $2"))
;=> "$1 <- $2, $1 <- $2"
All of the functions that construct sets such as set
and
sorted-set
allow duplicate elements to appear in their arguments,
and they are documented to treat this case as if by repeated uses of
conj
.
Similarly, all map constructor functions such as hash-map
,
array-map
, and sorted-map
allow duplicate keys, and are documented
to treat this case as if by repeated uses of assoc
.
As before, literal sets, e.g. #{1 2 3}
, do not allow duplicate
elements, and while elements can be expressions evaluated at run time
such as #{(inc x) (dec y)}
, this leads to a check for duplicates at
run time whenever the set needs to be constructed, throwing an
exception if any duplicates are found.
Similarly, literal maps do not allow duplicate keys. New to Clojure 1.5 is a performance optimization: if all keys are compile time constants but one or more values are expressions requiring evaluation at run time, duplicate keys are checked for once at compile time only, not each time a map is constructed at run time.
Most functions that take a collection and return a "modified" version
of that collection preserve the metadata that was on the input
collection, e.g. conj
, assoc
, dissoc
, etc. One notable
exception was into
, which would return a collection with metadata
nil
for several common types of input collections.
Now the functions into
, select-keys
, clojure.set/project
, and
clojure.set/rename
return collections with the same metadata as
their input collections.
*read-eval*
The new clojure.edn
namespace reads edn (http://edn-format.org) data,
and should be used for reading data from untrusted sources.
Clojure's core read* functions can evaluate code, and should not be
used to read data from untrusted sources. As of 1.5, *read-eval*
supports a documented set of thread-local bindings, see the doc string
for details.
*read-eval*
's default can be set to false by setting a system property:
-Dclojure.read.eval=false
when-first
now evaluates its expression only once.PersistentVector$ChunkedSeq
now implements Counted
interface, to avoid some cases where vector elements were being counted by iterating over their elements.assoc
now throws an exception if the last key argument is missing a value.*ns*
public static inner class LispReader.ReaderException(int line, Throwable cause)
Constructor changed to ReaderException(int line, int column, Throwable cause)
public Object clojure.lang.Agent.dispatch(IFn fn, ISeq args, boolean solo)
Replaced with dispatch(IFn fn, ISeq args, Executor exec)
1 Deprecated and Removed Features 1.1 Fields that Start With a Dash Can No Longer Be Accessed Using Dot Syntax 2 New/Improved Features 2.1 Reader Literals 2.2 clojure.core/mapv 2.3 clojure.core/filterv 2.4 clojure.core/ex-info and clojure.core/ex-data 2.5 clojure.core/reduce-kv 2.6 clojure.core/contains? Improved 2.7 clojure.core/min and clojure.core/max prefer NaN 2.8 clojure.java.io/as-file and clojure.java.io/as-url Handle URL-Escaping Better 2.9 New Dot Syntax for Record and Type Field Access 2.10 Record Factory Methods Available Inside defrecord 2.11 assert-args Displays Namespace and Line Number on Errors 2.12 File and Line Number Added to Earmuff Dynamic Warning 2.13 require Can Take a :refer Option 2.14 *compiler-options* Var 2.15 Improved Reporting of Invalid Characters in Unicode String Literals 2.16 clojure.core/hash No Longer Relies on .hashCode 2.17 Java 7 Documentation 2.18 loadLibrary Loads Library Using System ClassLoader 2.19 Java int is boxed as java.lang.Integer 3 Performance Enhancements 4 Bug Fixes
Clojure 1.4 introduces a field accessor syntax for the dot special form that aligns Clojure field lookup syntax with ClojureScript's.
For example, in Clojure 1.3, one can declare a record with a field starting with dash and access it like this:
(defrecord Bar [-a]) ;=> user.Bar
(.-a (Bar. 10)) ;=> 10
In 1.4, the above code results in IllegalArgumentException No matching field found: a for class user.Bar
However, the field may still be accessed as a keyword:
(:-a (Bar. 10)) ;=> 10
Clojure 1.4 supports reader literals, which are data structures tagged by a symbol to denote how they will be read.
When Clojure starts, it searches for files named data_readers.clj
at the root of the classpath. Each such file must contain a Clojure
map of symbols, like this:
{foo/bar my.project.foo/bar
foo/baz my.project/baz}
The key in each pair is a tag that will be recognized by the Clojure reader. The value in the pair is the fully-qualified name of a Var which will be invoked by the reader to parse the form following the tag. For example, given the data_readers.clj file above, the Clojure reader would parse this form:
#foo/bar [1 2 3]
by invoking the Var #'my.project.foo/bar
on the vector [1 2 3]
. The
data reader function is invoked on the form AFTER it has been read
as a normal Clojure data structure by the reader.
Reader tags without namespace qualifiers are reserved for Clojure. Default
reader tags are defined in clojure.core/default-data-readers
but may be
overridden in data_readers.clj
or by rebinding *data-readers*
.
Clojure supports literals for instants in the form
#inst "yyyy-mm-ddThh:mm:ss.fff+hh:mm"
. These literals are parsed as java.util.Date
s
by default. They can be parsed as java.util.Calendar
s or java.util.Timestamp
s
by binding *data-readers*
to use clojure.instant/read-instant-calendar
or
clojure.instant/read-instant-timestamp
.
(def instant "#inst \"@2010-11-12T13:14:15.666\"")
; Instants are read as java.util.Date by default
(= java.util.Date (class (read-string instant)))
;=> true
; Instants can be read as java.util.Calendar or java.util.Timestamp
(binding [*data-readers* {'inst read-instant-calendar}]
(= java.util.Calendar (class (read-string instant))))
;=> true
(binding [*data-readers* {'inst read-instant-timestamp}]
(= java.util.Timestamp (class (read-string instant))))
;=> true
Clojure supports literals for UUIDs in the form #uuid "uuid-string"
. These
literals are parsed as java.util.UUID
s.
mapv
takes a function f
and one or more collections and returns a
vector consisting of the result of applying f
to the set of first items of
each collection, followed by applying f
to the set of second items in each
collection, until any one of the collections is exhausted. Any remaining
items in other collections are ignored. f
should accept a number of arguments
equal to the number of collections.
(= [1 2 3] (mapv + [1 2 3]))
;=> true
(= [2 3 4] (mapv + [1 2 3] (repeat 1)))
;=> true
filterv
takes a predicate pred
and a collection and returns a vector
of the items in the collection for which (pred item)
returns true. pred
must be free of side-effects.
(= [] (filterv even? [1 3 5]))
;=> true
(= [2 4] (filterv even? [1 2 3 4 5]))
;=> true
ex-info
creates an instance of ExceptionInfo
. ExceptionInfo
is a
RuntimeException
subclass that takes a string msg
and a map of data.
(ex-info "Invalid use of robots" {:robots false})
;=> #<ExceptionInfo clojure.lang.ExceptionInfo: Invalid use of robots {:robots false}>
ex-data
is called with an exception and will retrieve that map of data
if the exception is an instance of ExceptionInfo
.
(ex-data (ex-info "Invalid use of robots" {:robots false}))
;=> {:robots false}
reduce-kv
reduces an associative collection. It takes a function f
,
an initial value init
and an associative collection coll
. f
should
be a function of 3 arguments. Returns the result of applying f
to init
,
the first key and the first value in coll
, then applying f
to that result
and the 2nd key and value, etc. If coll
contains no entries, returns init
and f is not called. Note that reduce-kv
is supported on vectors,
where the keys will be the ordinals.
(reduce-kv str "Hello " {:w \o :r \l :d \!})
;=> "Hello :rl:d!:wo"
(reduce-kv str "Hello " [\w \o \r \l \d \!])
;=> "Hello 0w1o2r3l4d5!"
contains?
now works with java.util.Set
.
min
and max
now give preference to returning NaN if either of their
arguments is NaN.
as-file
and as-url
now handle URL-escaping in both directions.
Clojure 1.4 introduces a field accessor syntax for the dot special form that aligns Clojure field lookup syntax with ClojureScript's.
In 1.4, to declare a record type and access its property x
, one can
write:
(defrecord Foo [x]) ;=> user.Foo
(.-x (Foo. 10)) ;=> 10
This addition makes it easier to write code that will run as expected in both Clojure and ClojureScript.
Prior to 1.4, you could not use the factory functions (->RecordClass
and map->RecordClass
) to construct a new record from inside a
defrecord
definition.
The following example did not work prior to 1.4, but is now
valid. This example makes use of ->Mean
which would have not yet
been available.
(defrecord Mean [last-winner]
Player
(choose [_] (if last-winner last-winner (random-choice)))
(update-strategy [_ me you] (->Mean (when (iwon? me you) me))))
assert-args
now uses &form to report the namespace and line number where
macro syntax errors occur.
When a variable is defined using earmuffs but is not declared dynamic, Clojure emits a warning. That warning now includes the file and line number.
require
can now take a :refer
option. :refer
takes a list of symbols
to refer from the namespace or :all
to bring in all public vars.
The dynamic var *compiler-options*
contains a map of options to send
to the Clojure compiler.
Supported options:
:elide-meta
: Have certain metadata elided during compilation. This
should be set to a collection of keywords.:disable-locals-clearing
: Set to true to disable clearing. Useful for
using a debugger.The main function of the Clojure compiler sets the
*compiler-options*
from properties prefixed by clojure.compiler
,
e.g.
java -Dclojure.compiler.elide-meta='[:doc :file :line]'
When the reader finds an invalid character in a Unicode string literal, it now reports the character instead of its numerical representation.
hash
no longer directly uses .hashCode() to return the hash of a Clojure
data structure. It calls clojure.lang.Util.hasheq
, which has its own implementation
for Integer, Short, Byte, and Clojure collections. This ensures that the hash code
returned is consistent with =
.
*core-java-api*
will now return the URL for the Java 7 Javadoc when you are
running Java 7.
A static method, loadLibrary
, was added to clojure.lang.RT
to load a
library using the system ClassLoader instead of Clojure's class loader.
Java int
s are now boxed as java.lang.Integer
s. See
the discussion on clojure-dev
for more information.
(= char char)
is now optimizedequiv
is inlined in variadic =toString
cached on keywords and symbols1 Deprecated and Removed Features 1.1 Earmuffed Vars are No Longer Automatically Considered Dynamic 1.2 ISeq No Longer Inherits from Sequential 1.3 Removed Bit Operation Support for Boxed Numbers 1.4 Ancillary Namespaces No Longer Auto-Load on Startup 1.5 Replicate Deprecated 2 New/Improved Features 2.1 Enhanced Primitive Support 2.2 defrecord and deftype Improvements 2.3 Better Exception Reporting 2.4 clojure.reflect/reflect 2.5 clojure.data/diff 2.6 clojure.core/every-pred and clojure.core/some-fn Combinators 2.7 clojure.core/realized? 2.8 clojure.core/with-redefs-fn & with-redefs 2.9 clojure.core/find-keyword 2.10 clojure.repl/pst 2.11 clojure.pprint/print-table 2.12 pprint respects *print-length* 2.13 compilation and deployment via Maven 2.14 internal keyword map uses weak refs 2.15 ^:const defs 2.16 Message Bearing Assert 2.17 Error Checking for defmulti Options 2.18 Removed Checked Exceptions 2.19 vector-of Takes Multiple Arguments 2.20 deref with timeout 2.21 Walk Support for sorted-by Collections 2.22 string.join Enhanced to Work with Sets 2.23 clojure.test-helper 2.24 Newline outputs platform-specific newline sequence 2.25 init-proxy and update-proxy return proxy 2.26 doc & find-doc moved to REPL 2.27 clojure.java.shell/sh accepts as input anything that clojure.java.io/copy does 2.28 InterruptedHandler Promoted to clojure.repl 2.29 Add support for running -main namespaces from clojure.main 2.30 Set thread names on agent thread pools 2.31 Add docstring support to def 2.32 Comp function returns identity when called with zero arity 2.33 Type hints can be applied to arg vectors 2.34 Binding Conveyance 3 Performance Enhancements 4 Bug Fixes 5 Modular Contrib
(def *fred*)
=> Warning: *fred* not declared dynamic and thus is not dynamically rebindable, but its name suggests otherwise. Please either indicate ^:dynamic ** or change the name.
This allows ISeq implementers to be in the map or set equality partition.
Bit Operations map directly to primitive operations
The following namespaces are no longer loaded on startup: clojure.set, clojure.xml, clojure.zip
Use repeat instead.
Full details here:
Details here: Defrecord Improvements
Details here: Error Handling
Additionally:
Better error messages:
Full details here: Reflection API
Recursively compares a and b, returning a tuple of [things-only-in-a things-only-in-b things-in-both]
(diff {:a 1 :b 2} {:a 1 :b 22 :c 3})
=> ({:b 2} {:c 3, :b 22} {:a 1})
every-pred takes a set of predicates and returns a function f that returns true if all of its composing predicates return a logical true value against all of its arguments, else it returns false.
((every-pred even?) 2 4 6)
=> true
((every-pred even?) 2 4 5)
=>false
some-fn takes a set of predicates and returns a function f that returns the first logical true value returned by one of its composing predicates against any of its arguments, else it returns logical false.
((some-fn even?) 2 4 5)
=> true
((some-fn odd?) 2 4 6)
=> false
Returns true if a value has been produced for a promise, delay, future or lazy sequence.
(let [x (range 5)]
(println (realized? x))
(first x)
(println (realized? x)))
=> false
=> true
with-redefs-fn temporarily redefines Vars during a call to func. with-redefs temporarily redefines Vars while executing the body.
(with-redefs [nil? :temp] (println nil?))
=> :temp
Returns a Keyword with the given namespace and name if one already exists.
(find-keyword "def")
=> :def
(find-keyword "fred")
=> nil
Prints a stack trace of the exception
(pst (IllegalArgumentException.))
IllegalArgumentException
user/eval27 (NO_SOURCE_FILE:18)
clojure.lang.Compiler.eval (Compiler.java:6355)
clojure.lang.Compiler.eval (Compiler.java:6322)
clojure.core/eval (core.clj:2699)
clojure.main/repl/read-eval-print--5906 (main.clj:244)
clojure.main/repl/fn--5911 (main.clj:265)
clojure.main/repl (main.clj:265)
clojure.main/repl-opt (main.clj:331)
clojure.main/main (main.clj:427)
clojure.lang.Var.invoke (Var.java:397)
clojure.lang.Var.applyTo (Var.java:518)
clojure.main.main (main.java:37)
Prints a collection of maps in a textual table.
(print-table [:fred :barney]
[{:fred "ethel"}
{:fred "wilma" :barney "betty"}])
===============
:fred | :barney
===============
ethel |
wilma | betty
===============
Assigning *print-length* now affects output of pprint
See the following pages for more information:
^:const lets you name primitive values with speedier reference.
(def constants
{:pi 3.14
:e 2.71})
(def ^:const pi (:pi constants))
(def ^:const e (:e constants))
The overhead of looking up :e and :pi in the map happens at compile time, as (:pi constants) and (:e constants) are evaluated when their parent def forms are evaluated.
Assert can take a second argument which will be printed when the assert fails
(assert (= 1 2) "1 is not equal to 2")
=> AssertionError Assert failed: 1 is not equal to 2
defmulti will check to verify that its options are valid. For example, the following code will throw an exception:
(defmulti fred :ethel :lucy :ricky)
=> IllegalArgumentException
Clojure does not throw checked exceptions
vector-of takes multiple args used to populate the array
(vector-of :int 1 2 3)
=> [1 2 3]
deref now takes a timeout option - when given with a blocking reference, will return the timeout-val if the timeout (in milliseconds) is reached before value is available.
(deref (promise) 10 :ethel)
=> :ethel
Walk modified to work on sorted-by collections
let [x (sorted-set-by > 1 2 3)] (walk inc reverse x))
=> (2 3 4)
Just like join works on other collections
(join " and " #{:fred :ethel :lucy})
=> ":lucy and :fred and :ethel"
All test helpers moved into clojure.test-helper
Newline sequence is output as \r\n on Windows now.
Now you can chain calls on the proxy
Adds special form docs to the REPL
This adds InputStream, Reader, File, byte[] to the list of inputs for clojure.java.shell/sh
Promoting this library eliminates the need for a dependency on old contrib.
This patch allows clojure.main to accept an argument pointing to a namespace to look for a -main function in. This allows users to write -main functions that will work the same whether the code is AOT-compiled for use in an executable jar or just run from source.
It's a best practice to name the threads in an executor thread pool with a custom ThreadFactory so that the purpose of these threads is clear in thread dumps and other runtime operational tools.
Patch causes thread names like:
clojure-agent-send-pool-%d (should be fixed # of threads)
clojure-agent-send-off-pool-%d (will be added and removed over time)
A def can now have a docstring between name and value.
(def foo "a foo" :foo)
(= (comp) identity)
=> true
You can hint different arities separately:
(defn hinted
(^String [])
(^Integer [a])
(^java.util.List [a & args]))
This is preferred over hinting the function name. Hinting the function name is still allowed for backward compatibility, but will likely be deprecated in a future release.
Clojure APIs that pass work off to other threads (e.g. send, send-off, pmap, future) now convey the dynamic bindings of the calling thread:
(def ^:dynamic *num* 1)
(binding [*num* 2] (future (println *num*)))
;; prints "2", not "1"
Complete list of Tickets for 1.3 Release.
CLJ-8 detect and report cyclic load dependencies
CLJ-31 compiler now correctly rejects attempts to recur across try (fn [x] (try (recur 1))) => CompilerException
CLJ-286 *out* being used as java.io.PrintWriter
CLJ-292 LazySeq.sval() nests RuntimeExceptions
CLJ-390 sends from agent error-handlers should be allowed
CLJ-426 case should handle hash collision
CLJ-430 clojure.java.io URL Coercion throws java.lang.ClassCastException
CLJ-432 deftype does not work if containing ns contains dashes
CLJ-433 munge should not munge $ (which isJavaIdentifierPart), should munge ' (which is not)
CLJ-435 stackoverflow exception in printing meta with :type
CLJ-437 Bugs in clojure.set/subset? and superset? for sets with false/nil elements
CLJ-439 Automatic type translation from Integer to Long
CLJ-444 Infinite recursion in Keyword.intern leads to stack overflow
CLJ-673 use system class loader when base loader is null
CLJ-678 into-array should work with all primitive types
CLJ-680 printing promises should not block
CLJ-682 cl-format: ~w throws an exception when not wrapped in a pretty-writer
CLJ-693 VerifyError with symbol metadata, macros, and defrecord
CLJ-702 case gives NPE when used with nil
CLJ-734 starting scope of let bindings seems incorrect from jdi perspective
CLJ-739 version.properties file is not closed
CLJ-751 cl-format: ~( throws an exception with an empty string
CLJ-780 race condition in reference cache on Java 5
floats were being boxed as Doubles, now they are boxed as Floats
several "holding onto head" fixes
In 1.3, the monolithic clojure-contrib.jar has been replaced by a modular system of contrib libraries, so that production systems can include only the code they actually need. This also allows individual contribs to have their own release cycles. Many contribs have moved forward by several point versions already. Documentation for updating applications to use the new contrib libraries is at http://dev.clojure.org/display/design/Where+Did+Clojure.Contrib+Go
Important Note: Many of the new modular contribs are compatible with both 1.2 and 1.3. This offers an incremental migration path: First, upgrade your contrib libraries while holding Clojure at 1.2, Then, in a separate step, upgrade to Clojure 1.3.
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