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5a2c6f0d4f
Plugin discovery documentation contained information about installing Elasticsearch 2.0 and installing an oracle JDK, both of which is no longer valid. While noticing that the instructions used cleartext HTTP to install packages, this commit replaces HTTPs links instead of HTTP where possible. In addition a few community links have been removed, as they do not seem to exist anymore. Co-authored-by: Alexander Reelsen <alexander@reelsen.net>
21 lines
1.0 KiB
Plaintext
21 lines
1.0 KiB
Plaintext
[[painless-lang-spec]]
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== Painless Language Specification
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Painless is a scripting language designed for security and performance.
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Painless syntax is similar to Java syntax along with some additional
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features such as dynamic typing, Map and List accessor shortcuts, and array
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initializers. As a direct comparison to Java, there are some important
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differences, especially related to the casting model. For more detailed
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conceptual information about the basic constructs that Painless and Java share,
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refer to the corresponding topics in the
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https://docs.oracle.com/javase/specs/jls/se8/html/index.html[Java Language
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Specification].
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Painless scripts are parsed and compiled using the https://www.antlr.org/[ANTLR4]
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and https://asm.ow2.org/[ASM] libraries. Scripts are compiled directly
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into Java Virtual Machine (JVM) byte code and executed against a standard JVM.
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This specification uses ANTLR4 grammar notation to describe the allowed syntax.
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However, the actual Painless grammar is more compact than what is shown here.
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include::painless-lang-spec/index.asciidoc[]
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