/**
 * {@link String}用の変換ユーティリティです。
 *
 * @author higa
 */
public abstract class StringConversionUtil {

    /** WAVE DASH */
    public static final char WAVE_DASH = '\u301C';

    /** FULLWIDTH TILDE */
    public static final char FULLWIDTH_TILDE = '\uFF5E';

    /** DOUBLE VERTICAL LINE */
    public static final char DOUBLE_VERTICAL_LINE = '\u2016';

    /** PARALLEL TO */

func (s *_TypeSet) underIs(f func(Type) bool) bool {
	if !s.hasTerms() {
		return f(nil)
	}
	for _, t := range s.terms {
		assert(t.typ != nil)
		// x == under(x) for ~x terms
		u := t.typ
		if !t.tilde {
			u = under(u)
		}
		if debug {
			assert(Identical(u, under(u)))
		}
		if !f(u) {
			return false
		}
	}
	return true
}

func (s *_TypeSet) underIs(f func(Type) bool) bool {
	if !s.hasTerms() {
		return f(nil)
	}
	for _, t := range s.terms {
		assert(t.typ != nil)
		// x == under(x) for ~x terms
		u := t.typ
		if !t.tilde {
			u = under(u)
		}
		if debug {
			assert(Identical(u, under(u)))
		}
		if !f(u) {
			return false
		}
	}
	return true
}

  pymdownx.superfences:
    custom_fences:
    - name: mermaid
      class: mermaid
      format: !!python/name:pymdownx.superfences.fence_code_format ''
  pymdownx.tabbed:
    alternate_style: true
  pymdownx.tilde: null
  attr_list: null
  md_in_html: null
extra:
  analytics:
    provider: google
    property: G-YNEVN69SC3
  social:
  - icon: fontawesome/brands/github-alt

}

// EmbeddedTerm = [ "~" ] Type .
func (p *parser) embeddedTerm() Expr {
	if trace {
		defer p.trace("embeddedTerm")()
	}

	if p.tok == _Operator && p.op == Tilde {
		t := new(Operation)
		t.pos = p.pos()
		t.Op = Tilde
		p.next()
		t.X = p.type_()
		return t
	}

	t := p.typeOrNil()
	if t == nil {
		t = p.badExpr()
		p.syntaxError("expected ~ term or type")

		// parameters.
		reportReason := len(m.seen) == 1

		for _, term := range terms {
			if !m.match(term.Type(), topLevel) {
				if reportReason {
					if term.Tilde() {
						m.reason = fmt.Sprintf("contains ~%s", term.Type())
					} else {
						m.reason = fmt.Sprintf("contains %s", term.Type())
					}
				}
				return false
			}
		}
		return true
	}

			// representable by each specific type in the type set of T.
			return Tp.is(func(t *term) bool {
				if t == nil {
					return false
				}
				// A term may be a tilde term but the underlying
				// type of an untyped value doesn't change so we
				// don't need to do anything special.
				newType, _, _ := check.implicitTypeAndValue(x, t.typ)
				return newType != nil

				// first function that got substituted => allocate new out slice
				// and copy all functions
				new := make([]*Term, len(in))
				copy(new, out)
				out = new
				copied = true
			}
			out[i] = NewTerm(t.tilde, u)
		}
	}
	return
}

// replaceRecvType updates any function receivers that have type old to have
// type new. It does not modify the input slice; if modifications are required,

			// representable by each specific type in the type set of T.
			return Tp.is(func(t *term) bool {
				if t == nil {
					return false
				}
				// A term may be a tilde term but the underlying
				// type of an untyped value doesn't change so we
				// don't need to do anything special.
				newType, _, _ := check.implicitTypeAndValue(x, t.typ)
				return newType != nil

				// first function that got substituted => allocate new out slice
				// and copy all functions
				new := make([]*Term, len(in))
				copy(new, out)
				out = new
				copied = true
			}
			out[i] = NewTerm(t.tilde, u)
		}
	}
	return
}

// replaceRecvType updates any function receivers that have type old to have
// type new. It does not modify the input slice; if modifications are required,