<!--{
	"Title": "The Go Programming Language Specification",
	"Subtitle": "Language version go1.26 (Dec 2, 2025)",
	"Path": "/ref/spec"
}-->

<h2 id="Introduction">Introduction</h2>

<p>
This is the reference manual for the Go programming language.
For more information and other documents, see <a href="/">go.dev</a>.
</p>

<p>
Go is a general-purpose language designed with systems programming

// - implement filters and create a test where a plugin fails if the right classes are not filtered
// - plugins with a dependency the same as the core but different versions, make it fail then fix it

  /*
 *
 * h2. Concerns for the plugin manager
 *
 * h3. resolving the dependencies of a plugin - these could be resolved remotely at runtime or, -
 * they could be resolved from a local repository - I think we need a simple dependency model here

        {@code excludes} elements. The kind of sources (codes, resources, <i>etc.</i>) and their
        usage (main code, tests, <i>etc.</i>) is specified by the {@code scope} element.

        <h2>Default source directories</h2>
        If no source directories are specified, the default values depend on whether module names are specified:
        <ul>
          <li>{@code src/${scope}/${lang}} if no module is specified</li>

		return FormatUnknown, nil, headerError{"cannot manually encode TypeXHeader, TypeGNULongName, or TypeGNULongLink headers"}
	case TypeXGlobalHeader:
		h2 := Header{Name: h.Name, Typeflag: h.Typeflag, Xattrs: h.Xattrs, PAXRecords: h.PAXRecords, Format: h.Format}
		if !reflect.DeepEqual(h, h2) {
			return FormatUnknown, nil, headerError{"only PAXRecords should be set for TypeXGlobalHeader"}
		}
		whyOnlyPAX = "only PAX supports TypeXGlobalHeader"

import java.util.logging.Logger;
import org.jspecify.annotations.Nullable;

/**
 * A builder of {@link LoadingCache} and {@link Cache} instances.
 *
 * <h2>Prefer <a href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a> over Guava's caching
 * API</h2>
 *
 * <p>The successor to Guava's caching API is <a
 * href="https://github.com/ben-manes/caffeine/wiki">Caffeine</a>. Its API is designed to make it a

<!--{
	"Title": "A Quick Guide to Go's Assembler",
	"Path":  "/doc/asm"
}-->

<h2 id="introduction">A Quick Guide to Go's Assembler</h2>

<p>
This document is a quick outline of the unusual form of assembly language used by the <code>gc</code> Go compiler.
The document is not comprehensive.
</p>

<p>
The assembler is based on the input style of the Plan 9 assemblers, which is documented in detail

    introduction to this new API.

 *  New: APIs to iterate and selectively clear the response cache.
 *  New: Support for SOCKS proxies.
 *  New: Support for `TLS_FALLBACK_SCSV`.
 *  New: Update HTTP/2 support to `h2-16` and `hpack-10`.
 *  New: APIs to prevent retrying non-idempotent requests.
 *  Fix: Drop NPN support. Going forward we support ALPN only.
 *  Fix: The hostname verifier is now strict. This is consistent with the hostname

     *     represented as a combination of scheme, host and port. When empty, the origin is that of
     *     the `streamId`.
     * @param protocol an ALPN protocol, such as `h2`.
     * @param host an IP address or hostname.
     * @param port the IP port associated with the service.
     * @param maxAge time in seconds that this alternative is considered fresh.
     */
    fun alternateService(

}\n}\n","// stylelint-disable selector-list-comma-newline-after\n\n//\n// Headings\n//\n\nh1, h2, h3, h4, h5, h6,\n.h1, .h2, .h3, .h4, .h5, .h6 {\n  margin-bottom: $headings-margin-bottom;\n  font-family: $headings-font-family;\n  font-weight: $headings-font-weight;\n  line-height: $headings-line-height;\n  color: $headings-color;\n}\n\nh1, .h1 { @include font-size($h1-font-size); }\nh2, .h2 { @include font-size($h2-font-size); }\nh3, .h3 { @include font-size($h3-font-size); }\nh4, .h4 { @include font-...

utton{font:inherit;-webkit-appearance:button}output{display:inline-block}summary{display:list-item;cursor:pointer}template{display:none}[hidden]{display:none!important}.h1,.h2,.h3,.h4,.h5,.h6,h1,h2,h3,h4,h5,h6{margin-bottom:.5rem;font-family:inherit;font-weight:500;line-height:1.2;color:inherit}.h1,h1{font-size:2.5rem}.h2,h2{font-size:2rem}.h3,h3{font-size:1.75rem}.h4,h4{font-size:1.5rem}.h5,h5{font-size:1.25rem}.h6,h6{font-size:1rem}.lead{font-size:1.25rem;font-weight:300}.display-1{font-size:6...