if as, ok := s.(*AssignStmt); ok && as.Op == 0 {
			// Emphasize complex Lhs and Rhs of assignment with parentheses to highlight '='.
			str = "assignment " + emphasize(as.Lhs) + " = " + emphasize(as.Rhs)
		} else {
			str = String(s)
		}
		p.syntaxErrorAt(s.Pos(), fmt.Sprintf("cannot use %s as value", str))
	}

	p.xnest = outer
	return
}

// emphasize returns a string representation of x, with (top-level)

@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
// TODO(kevinb): I think we should push everything down to "BaseImmutableCollection" or something,
// just to do everything we can to emphasize the "practically an interface" nature of this class.
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  /*

@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
// TODO(kevinb): I think we should push everything down to "BaseImmutableCollection" or something,
// just to do everything we can to emphasize the "practically an interface" nature of this class.
public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  /*

        List<Color> colors = new ArrayList<Color>();
        for (Style.Emphasis emphasis : style.getEmphasises()) {
            if (emphasis.equals(Style.Emphasis.BOLD)) {
                colors.add(newBoldColor());
            } else if (emphasis.equals(Style.Emphasis.REVERSE)) {
                colors.add(newReverseColor());
            } else if (emphasis.equals(Style.Emphasis.ITALIC)) {
                colors.add(newItalicColor());
            }

    private static String expected(String text) {
        return emphatize(text, "blue");
    }

    private static String actual(String text) {
        return emphatize(text, "#ee442f");
    }

    private static String warning(String text) {
        return emphatize(text, "#c59434");
    }

    private static String grey(String text) {
        return emphatize(text, "#cccccc");
    }

	case '*', '~':
		// “A single * character can open emphasis iff
		// it is part of a left-flanking delimiter run.”

		// “A double ** can open strong emphasis iff
		// it is part of a left-flanking delimiter run.”
		canOpen = leftFlank

		// “A single * character can close emphasis iff
		// it is part of a right-flanking delimiter run.”

		// “A double ** can close strong emphasis iff

layout: article
---

<!--
This document is kept in the Go repo, not x/website,
because it documents the full list of known GODEBUG settings,
which are tied to a specific release.
-->

## Introduction {#intro}

Go's emphasis on backwards compatibility is one of its key strengths.
There are, however, times when we cannot maintain complete compatibility.
If code depends on buggy (including insecure) behavior,
then fixing the bug will break that code.

// autoLinkMore rewrites any extended autolinks in the body
// and returns the result.
//
// body is a list of Plain, Emph, Strong, and Del nodes.
// Two Plains only appear consecutively when one is a
// potential emphasis marker that ended up being plain after all, like "_" or "**".
// There are no Link nodes.
//
// The GitHub “spec” declares that “autolinks can only come at the

    margin-top: 0;
    margin-bottom: 0.6rem;
}

.example-contents > p {
    margin: 0;
}

.example-break, .figure-break {
    display: none;
}

.exampleLocation .emphasis em {
    font-style: normal;
    font-weight: bold;
}

.appendix h1 {
    margin-bottom: 1.0em;
}

.footnote sup {
    vertical-align: baseline;
    font-size: 100%;
}

of final Grid Layout. Use grid-column.",{node:f});return}else if(p==="display"&&m==="box"){t.warn("You should write display: flex by final spec instead of display: box",{node:f});return}else if(p==="text-emphasis-position")(m==="under"||m==="over")&&t.warn("You should use 2 values for text-emphasis-position For example, `under left` instead of just `under`.",{node:f});else if(/^(align|justify|place)-(items|content)$/.test(p)&&u(f))(m==="start"||m==="end")&&t.warn(`${m} value has mixed support, consider...