Generate reference links for painless API (#22775)

Adds "Appending B. Painless API Reference", a reference of all classes
and methods available from Painless. Removes links to java packages
because they contain methods that we don't expose and don't contain
methods that we do expose (the ones in Augmentation). Instead this
generates a list of every class and every exposed method using the same
type information available to the
interpreter/compiler/whatever-we-call-it. From there you can jump to
the relevant docs.

Right now you build all the asciidoc files by running
```
gradle generatePainlessApi
```

These files are expected to be committed because we build the docs
without running `gradle`.

Also changes the output of `Debug.explain` so that it is easy to
search for the class in the generated reference documentation.

You can also run it in an IDE safely if you pass the path to the
directory in which to generate the docs as the first parameter. It'll
blow away the entire directory an recreate it from scratch so be careful.

And then you can build the docs by running something like:
```
../docs/build_docs.pl --out ../built_docs/ --doc docs/reference/index.asciidoc --open
```

That is, if you have checked out https://github.com/elastic/docs in
`../docs`. Wait a minute or two and your browser will pop open in with
all of Elasticsearch's reference documentation. If you go to
`http://localhost:8000/painless-api-reference.html` you can see this
list. Or you can get there by following the links to `Modules` and
`Scripting` and `Painless` and then clicking the link in the paragraphs
below titled `Appendix B. Painless API Reference`.

I like having these in asciidoc because we can deep link to them from the
rest of the guide with constructs like
`<<painless-api-reference-Object-hashCode-0>>` and
`<<painless-api-reference->>` and we get link checking. Then the only
brittle link maintenance bit is the link generation for javadoc. Which
sucks. But I think it is important that we link to the methods directly
so they are easy to find.

Relates to #22720

Author: nik9000

docs/reference/index.asciidoc

@@ -20,6 +20,27 @@ release-state can be: released | prerelease | unreleased
 :issue:          https://github.com/elastic/elasticsearch/issues/
 :pull:           https://github.com/elastic/elasticsearch/pull/
 
+
+///////
+Javadoc roots used to generate links from Painless's API reference
+///////
+:java8-javadoc: https://docs.oracle.com/javase/8/docs/api
+:java9-javadoc: http://download.java.net/java/jigsaw/docs/api
+:joda-time-javadoc: http://www.joda.org/joda-time/apidocs
+:lucene-core-javadoc: http://lucene.apache.org/core/6_4_0/core
+
+ifeval::["{release-state}"=="unreleased"]
+:elasticsearch-javadoc: https://snapshots.elastic.co/javadoc/org/elasticsearch/elasticsearch/{version}-SNAPSHOT
+:painless-javadoc: https://snapshots.elastic.co/javadoc/org/elasticsearch/painless/lang-painless/{version}-SNAPSHOT
+endif::[]
+
+ifeval::["{release-state}"!="unreleased"]
+:elasticsearch-javadoc: https://artifacts.elastic.co/javadoc/org/elasticsearch/elasticsearch/{version}
+:painless-javadoc: https://artifacts.elastic.co/javadoc/org/elasticsearch/painless/lang-painless/{version}
+endif::[]
+
+
+
 include::getting-started.asciidoc[]
 
 include::setup.asciidoc[]
@@ -62,4 +83,6 @@ include::glossary.asciidoc[]
  include::release-notes.asciidoc[]
 //////
 
+include::painless-api-reference.asciidoc[]
+
 include::redirects.asciidoc[]

docs/reference/modules/scripting/painless-debugging.asciidoc

@@ -38,23 +38,24 @@ POST /hockey/player/1/_explain
 // we have to override it to get a normal shaped response
 
 Which shows that the class of `doc.first` is
-`org.elasticsearch.index.fielddata.ScriptDocValues$Longs` by responding with:
+`org.elasticsearch.index.fielddata.ScriptDocValues.Longs` by responding with:
 
 [source,js]
 ---------------------------------------------------------
 {
    "error": {
       "type": "script_exception",
-      "class": "org.elasticsearch.index.fielddata.ScriptDocValues$Longs",
       "to_string": "[1, 9, 27]",
+      "painless_class": "org.elasticsearch.index.fielddata.ScriptDocValues.Longs",
+      "java_class": "org.elasticsearch.index.fielddata.ScriptDocValues$Longs",
       ...
    },
    "status": 500
 }
 ---------------------------------------------------------
 // TESTRESPONSE[s/\.\.\./"script_stack": $body.error.script_stack, "script": $body.error.script, "lang": $body.error.lang, "caused_by": $body.error.caused_by, "root_cause": $body.error.root_cause, "reason": $body.error.reason/]
 
-You can use the same trick to see that `_source` is a `java.util.LinkedHashMap`
+You can use the same trick to see that `_source` is a `LinkedHashMap`
 in the `_update` API:
 
 [source,js]
@@ -78,8 +79,9 @@ The response looks like:
     "reason": "failed to execute script",
     "caused_by": {
       "type": "script_exception",
-      "class": "java.util.LinkedHashMap",
       "to_string": "{gp=[26, 82, 1], last=gaudreau, assists=[17, 46, 0], first=johnny, goals=[9, 27, 1]}",
+      "painless_class": "LinkedHashMap",
+      "java_class": "java.util.LinkedHashMap",
       ...
     }
   },
@@ -90,19 +92,5 @@ The response looks like:
 // TESTRESPONSE[s/\.\.\./"script_stack": $body.error.caused_by.script_stack, "script": $body.error.caused_by.script, "lang": $body.error.caused_by.lang, "caused_by": $body.error.caused_by.caused_by, "reason": $body.error.caused_by.reason/]
 // TESTRESPONSE[s/"to_string": ".+"/"to_string": $body.error.caused_by.to_string/]
 
-// TODO we should build some javadoc like mashup so people don't have to jump through these hoops.
-
-Once you have the class of an object you can go
-https://github.com/elastic/elasticsearch/tree/{branch}/modules/lang-painless/src/main/resources/org/elasticsearch/painless[here]
-and check the available methods. Painless uses a strict whitelist to prevent
-scripts that don't work well with Elasticsearch and all whitelisted methods
-are listed in a file named after the package of the object (everything before
-the last `.`). So `java.util.Map` is listed in a file named `java.util.txt`
-starting on the line that looks like `class Map -> java.util.Map {`.
-
-With the list of whitelisted methods in hand you can turn to either
-https://docs.oracle.com/javase/8/docs/api/[Javadoc],
-https://github.com/elastic/elasticsearch/tree/{branch}[Elasticsearch's source tree]
-or, for whitelisted methods ending in `*`, the
-https://github.com/elastic/elasticsearch/blob/{branch}/modules/lang-painless/src/main/java/org/elasticsearch/painless/Augmentation.java[Augmentation]
-class.
+Once you have a class you can go to <<painless-api-reference>> to see a list of
+available methods.

docs/reference/modules/scripting/painless.asciidoc

@@ -10,16 +10,18 @@ default.
 
 The Painless syntax is similar to http://groovy-lang.org/index.html[Groovy].
 
-You can use Painless anywhere a script can be used in Elasticsearch--simply set the `lang` parameter
-to `painless`.
+You can use Painless anywhere a script can be used in Elasticsearch. It is the
+default if you don't set the `lang` parameter but if you want to be explicit you
+can set the `lang` parameter to `painless`.
 
 [[painless-features]]
 [float]
 == Painless Features
 
 * Fast performance: https://benchmarks.elastic.co/index.html#search_qps_scripts[several times faster] than the alternatives.
 
-* Safety: Fine-grained <<painless-api, whitelist>> with method call/field granularity.
+* Safety: Fine-grained whitelist with method call/field granularity. See
+<<painless-api-reference>> for a complete list of available classes and methods.
 
 * Optional typing: Variables and parameters can use explicit types or the dynamic `def` type.
 
@@ -320,28 +322,3 @@ Note: all of the `_update_by_query` examples above could really do with a
 <<query-dsl-script-query>> it wouldn't be as efficient as using any other query
 because script queries aren't able to use the inverted index to limit the
 documents that they have to check.
-
-[float]
-[[painless-api]]
-== Painless API
-
-The following Java packages are available for use in the Painless language:
-
-* https://docs.oracle.com/javase/8/docs/api/java/lang/package-summary.html[java.lang]
-* https://docs.oracle.com/javase/8/docs/api/java/math/package-summary.html[java.math]
-* https://docs.oracle.com/javase/8/docs/api/java/text/package-summary.html[java.text]
-* https://docs.oracle.com/javase/8/docs/api/java/time/package-summary.html[java.time]
-* https://docs.oracle.com/javase/8/docs/api/java/time/chrono/package-summary.html[java.time.chrono]
-* https://docs.oracle.com/javase/8/docs/api/java/time/format/package-summary.html[java.time.format]
-* https://docs.oracle.com/javase/8/docs/api/java/time/temporal/package-summary.html[java.time.temporal]
-* https://docs.oracle.com/javase/8/docs/api/java/time/zone/package-summary.html[java.time.zone]
-* https://docs.oracle.com/javase/8/docs/api/java/util/package-summary.html[java.util]
-* https://docs.oracle.com/javase/8/docs/api/java/util/function/package-summary.html[java.util.function]
-* https://docs.oracle.com/javase/8/docs/api/java/util/regex/package-summary.html[java.util.regex]
-* https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html[java.util.stream]
-
-Note that unsafe classes and methods are not included, there is no support for:
-
-* Manipulation of processes and threads
-* Input/Output
-* Reflection

docs/reference/painless-api-reference.asciidoc

@@ -0,0 +1,17 @@
+["appendix",id="painless-api-reference"]
+= Painless API Reference
+
+<<modules-scripting-painless,Painless>> has a strict whitelist for methods and
+classes to make sure that all painless scripts are secure and fast. Most of
+these methods are exposed directly from the JRE while others are part of
+Elasticsearch or Painless itself. Below is a list of all available methods
+grouped under the classes on which you can call them. Clicking on the method
+name takes you to the documentation for the method.
+
+NOTE: Methods defined in the JRE also have a `(java 9)` link which can be used
+to see the method's documentation in Java 9 while clicking on the method's name
+goes to the Java 8 documentation. Usually these aren't different but it is
+worth going to the version that matches the version of Java you are using to
+run Elasticsearch just in case.
+
+include::painless-api-reference/index.asciidoc[]

docs/reference/painless-api-reference/List.asciidoc

@@ -0,0 +1,22 @@
+////
+Automatically generated by PainlessDocGenerator. Do not edit.
+Rebuild by running `gradle generatePainlessApi`.
+////
+
+[[painless-api-reference-List]]++List++::
+* ++[[painless-api-reference-List-add-2]]void link:{java8-javadoc}/java/util/List.html#add%2Dint%2Djava.lang.Object%2D[add](int, def)++ (link:{java9-javadoc}/java/util/List.html#add%2Dint%2Djava.lang.Object%2D[java 9])
+* ++[[painless-api-reference-List-addAll-2]]boolean link:{java8-javadoc}/java/util/List.html#addAll%2Dint%2Djava.util.Collection%2D[addAll](int, <<painless-api-reference-Collection,Collection>>)++ (link:{java9-javadoc}/java/util/List.html#addAll%2Dint%2Djava.util.Collection%2D[java 9])
+* ++[[painless-api-reference-List-equals-1]]boolean link:{java8-javadoc}/java/util/List.html#equals%2Djava.lang.Object%2D[equals](<<painless-api-reference-Object,Object>>)++ (link:{java9-javadoc}/java/util/List.html#equals%2Djava.lang.Object%2D[java 9])
+* ++[[painless-api-reference-List-get-1]]def link:{java8-javadoc}/java/util/List.html#get%2Dint%2D[get](int)++ (link:{java9-javadoc}/java/util/List.html#get%2Dint%2D[java 9])
+* ++[[painless-api-reference-List-getLength-0]]int link:{painless-javadoc}/org/elasticsearch/painless/api/Augmentation.html#getLength%2Djava.util.List%2D[getLength]()++
+* ++[[painless-api-reference-List-hashCode-0]]int link:{java8-javadoc}/java/util/List.html#hashCode%2D%2D[hashCode]()++ (link:{java9-javadoc}/java/util/List.html#hashCode%2D%2D[java 9])
+* ++[[painless-api-reference-List-indexOf-1]]int link:{java8-javadoc}/java/util/List.html#indexOf%2Djava.lang.Object%2D[indexOf](def)++ (link:{java9-javadoc}/java/util/List.html#indexOf%2Djava.lang.Object%2D[java 9])
+* ++[[painless-api-reference-List-lastIndexOf-1]]int link:{java8-javadoc}/java/util/List.html#lastIndexOf%2Djava.lang.Object%2D[lastIndexOf](def)++ (link:{java9-javadoc}/java/util/List.html#lastIndexOf%2Djava.lang.Object%2D[java 9])
+* ++[[painless-api-reference-List-listIterator-0]]<<painless-api-reference-ListIterator,ListIterator>> link:{java8-javadoc}/java/util/List.html#listIterator%2D%2D[listIterator]()++ (link:{java9-javadoc}/java/util/List.html#listIterator%2D%2D[java 9])
+* ++[[painless-api-reference-List-listIterator-1]]<<painless-api-reference-ListIterator,ListIterator>> link:{java8-javadoc}/java/util/List.html#listIterator%2Dint%2D[listIterator](int)++ (link:{java9-javadoc}/java/util/List.html#listIterator%2Dint%2D[java 9])
+* ++[[painless-api-reference-List-remove-1]]def link:{java8-javadoc}/java/util/List.html#remove%2Dint%2D[remove](int)++ (link:{java9-javadoc}/java/util/List.html#remove%2Dint%2D[java 9])
+* ++[[painless-api-reference-List-replaceAll-1]]void link:{java8-javadoc}/java/util/List.html#replaceAll%2Djava.util.function.UnaryOperator%2D[replaceAll](<<painless-api-reference-UnaryOperator,UnaryOperator>>)++ (link:{java9-javadoc}/java/util/List.html#replaceAll%2Djava.util.function.UnaryOperator%2D[java 9])
+* ++[[painless-api-reference-List-set-2]]def link:{java8-javadoc}/java/util/List.html#set%2Dint%2Djava.lang.Object%2D[set](int, def)++ (link:{java9-javadoc}/java/util/List.html#set%2Dint%2Djava.lang.Object%2D[java 9])
+* ++[[painless-api-reference-List-sort-1]]void link:{java8-javadoc}/java/util/List.html#sort%2Djava.util.Comparator%2D[sort](<<painless-api-reference-Comparator,Comparator>>)++ (link:{java9-javadoc}/java/util/List.html#sort%2Djava.util.Comparator%2D[java 9])
+* ++[[painless-api-reference-List-subList-2]]<<painless-api-reference-List,List>> link:{java8-javadoc}/java/util/List.html#subList%2Dint%2Dint%2D[subList](int, int)++ (link:{java9-javadoc}/java/util/List.html#subList%2Dint%2Dint%2D[java 9])
+* Inherits methods from ++<<painless-api-reference-Collection,Collection>>++, ++<<painless-api-reference-Iterable,Iterable>>++, ++<<painless-api-reference-Object,Object>>++

docs/reference/painless-api-reference/Math.asciidoc

@@ -0,0 +1,46 @@
+////
+Automatically generated by PainlessDocGenerator. Do not edit.
+Rebuild by running `gradle generatePainlessApi`.
+////
+
+[[painless-api-reference-Math]]++Math++::
+** [[painless-api-reference-Math-E]]static double link:{java8-javadoc}/java/lang/Math.html#E[E] (link:{java9-javadoc}/java/lang/Math.html#E[java 9])
+** [[painless-api-reference-Math-PI]]static double link:{java8-javadoc}/java/lang/Math.html#PI[PI] (link:{java9-javadoc}/java/lang/Math.html#PI[java 9])
+* ++[[painless-api-reference-Math-IEEEremainder-2]]static double link:{java8-javadoc}/java/lang/Math.html#IEEEremainder%2Ddouble%2Ddouble%2D[IEEEremainder](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#IEEEremainder%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-abs-1]]static double link:{java8-javadoc}/java/lang/Math.html#abs%2Ddouble%2D[abs](double)++ (link:{java9-javadoc}/java/lang/Math.html#abs%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-acos-1]]static double link:{java8-javadoc}/java/lang/Math.html#acos%2Ddouble%2D[acos](double)++ (link:{java9-javadoc}/java/lang/Math.html#acos%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-asin-1]]static double link:{java8-javadoc}/java/lang/Math.html#asin%2Ddouble%2D[asin](double)++ (link:{java9-javadoc}/java/lang/Math.html#asin%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-atan-1]]static double link:{java8-javadoc}/java/lang/Math.html#atan%2Ddouble%2D[atan](double)++ (link:{java9-javadoc}/java/lang/Math.html#atan%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-atan2-2]]static double link:{java8-javadoc}/java/lang/Math.html#atan2%2Ddouble%2Ddouble%2D[atan2](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#atan2%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-cbrt-1]]static double link:{java8-javadoc}/java/lang/Math.html#cbrt%2Ddouble%2D[cbrt](double)++ (link:{java9-javadoc}/java/lang/Math.html#cbrt%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-ceil-1]]static double link:{java8-javadoc}/java/lang/Math.html#ceil%2Ddouble%2D[ceil](double)++ (link:{java9-javadoc}/java/lang/Math.html#ceil%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-copySign-2]]static double link:{java8-javadoc}/java/lang/Math.html#copySign%2Ddouble%2Ddouble%2D[copySign](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#copySign%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-cos-1]]static double link:{java8-javadoc}/java/lang/Math.html#cos%2Ddouble%2D[cos](double)++ (link:{java9-javadoc}/java/lang/Math.html#cos%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-cosh-1]]static double link:{java8-javadoc}/java/lang/Math.html#cosh%2Ddouble%2D[cosh](double)++ (link:{java9-javadoc}/java/lang/Math.html#cosh%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-exp-1]]static double link:{java8-javadoc}/java/lang/Math.html#exp%2Ddouble%2D[exp](double)++ (link:{java9-javadoc}/java/lang/Math.html#exp%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-expm1-1]]static double link:{java8-javadoc}/java/lang/Math.html#expm1%2Ddouble%2D[expm1](double)++ (link:{java9-javadoc}/java/lang/Math.html#expm1%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-floor-1]]static double link:{java8-javadoc}/java/lang/Math.html#floor%2Ddouble%2D[floor](double)++ (link:{java9-javadoc}/java/lang/Math.html#floor%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-hypot-2]]static double link:{java8-javadoc}/java/lang/Math.html#hypot%2Ddouble%2Ddouble%2D[hypot](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#hypot%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-log-1]]static double link:{java8-javadoc}/java/lang/Math.html#log%2Ddouble%2D[log](double)++ (link:{java9-javadoc}/java/lang/Math.html#log%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-log10-1]]static double link:{java8-javadoc}/java/lang/Math.html#log10%2Ddouble%2D[log10](double)++ (link:{java9-javadoc}/java/lang/Math.html#log10%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-log1p-1]]static double link:{java8-javadoc}/java/lang/Math.html#log1p%2Ddouble%2D[log1p](double)++ (link:{java9-javadoc}/java/lang/Math.html#log1p%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-max-2]]static double link:{java8-javadoc}/java/lang/Math.html#max%2Ddouble%2Ddouble%2D[max](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#max%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-min-2]]static double link:{java8-javadoc}/java/lang/Math.html#min%2Ddouble%2Ddouble%2D[min](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#min%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-nextAfter-2]]static double link:{java8-javadoc}/java/lang/Math.html#nextAfter%2Ddouble%2Ddouble%2D[nextAfter](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#nextAfter%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-nextDown-1]]static double link:{java8-javadoc}/java/lang/Math.html#nextDown%2Ddouble%2D[nextDown](double)++ (link:{java9-javadoc}/java/lang/Math.html#nextDown%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-nextUp-1]]static double link:{java8-javadoc}/java/lang/Math.html#nextUp%2Ddouble%2D[nextUp](double)++ (link:{java9-javadoc}/java/lang/Math.html#nextUp%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-pow-2]]static double link:{java8-javadoc}/java/lang/Math.html#pow%2Ddouble%2Ddouble%2D[pow](double, double)++ (link:{java9-javadoc}/java/lang/Math.html#pow%2Ddouble%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-random-0]]static double link:{java8-javadoc}/java/lang/Math.html#random%2D%2D[random]()++ (link:{java9-javadoc}/java/lang/Math.html#random%2D%2D[java 9])
+* ++[[painless-api-reference-Math-rint-1]]static double link:{java8-javadoc}/java/lang/Math.html#rint%2Ddouble%2D[rint](double)++ (link:{java9-javadoc}/java/lang/Math.html#rint%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-round-1]]static long link:{java8-javadoc}/java/lang/Math.html#round%2Ddouble%2D[round](double)++ (link:{java9-javadoc}/java/lang/Math.html#round%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-scalb-2]]static double link:{java8-javadoc}/java/lang/Math.html#scalb%2Ddouble%2Dint%2D[scalb](double, int)++ (link:{java9-javadoc}/java/lang/Math.html#scalb%2Ddouble%2Dint%2D[java 9])
+* ++[[painless-api-reference-Math-signum-1]]static double link:{java8-javadoc}/java/lang/Math.html#signum%2Ddouble%2D[signum](double)++ (link:{java9-javadoc}/java/lang/Math.html#signum%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-sin-1]]static double link:{java8-javadoc}/java/lang/Math.html#sin%2Ddouble%2D[sin](double)++ (link:{java9-javadoc}/java/lang/Math.html#sin%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-sinh-1]]static double link:{java8-javadoc}/java/lang/Math.html#sinh%2Ddouble%2D[sinh](double)++ (link:{java9-javadoc}/java/lang/Math.html#sinh%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-sqrt-1]]static double link:{java8-javadoc}/java/lang/Math.html#sqrt%2Ddouble%2D[sqrt](double)++ (link:{java9-javadoc}/java/lang/Math.html#sqrt%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-tan-1]]static double link:{java8-javadoc}/java/lang/Math.html#tan%2Ddouble%2D[tan](double)++ (link:{java9-javadoc}/java/lang/Math.html#tan%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-tanh-1]]static double link:{java8-javadoc}/java/lang/Math.html#tanh%2Ddouble%2D[tanh](double)++ (link:{java9-javadoc}/java/lang/Math.html#tanh%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-toDegrees-1]]static double link:{java8-javadoc}/java/lang/Math.html#toDegrees%2Ddouble%2D[toDegrees](double)++ (link:{java9-javadoc}/java/lang/Math.html#toDegrees%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-toRadians-1]]static double link:{java8-javadoc}/java/lang/Math.html#toRadians%2Ddouble%2D[toRadians](double)++ (link:{java9-javadoc}/java/lang/Math.html#toRadians%2Ddouble%2D[java 9])
+* ++[[painless-api-reference-Math-ulp-1]]static double link:{java8-javadoc}/java/lang/Math.html#ulp%2Ddouble%2D[ulp](double)++ (link:{java9-javadoc}/java/lang/Math.html#ulp%2Ddouble%2D[java 9])
+* Inherits methods from ++<<painless-api-reference-Object,Object>>++