func writeValue()

in starlark/value.go [1131:1220]
78 lines of code
24 McCabe index (conditional complexity)

func writeValue(out *strings.Builder, x Value, path []Value) {
	switch x := x.(type) {
	case nil:
		out.WriteString("<nil>") // indicates a bug

	// These four cases are duplicates of T.String(), for efficiency.
	case NoneType:
		out.WriteString("None")

	case Int:
		out.WriteString(x.String())

	case Bool:
		if x {
			out.WriteString("True")
		} else {
			out.WriteString("False")
		}

	case String:
		out.WriteString(syntax.Quote(string(x), false))

	case *List:
		out.WriteByte('[')
		if pathContains(path, x) {
			out.WriteString("...") // list contains itself
		} else {
			for i, elem := range x.elems {
				if i > 0 {
					out.WriteString(", ")
				}
				writeValue(out, elem, append(path, x))
			}
		}
		out.WriteByte(']')

	case Tuple:
		out.WriteByte('(')
		for i, elem := range x {
			if i > 0 {
				out.WriteString(", ")
			}
			writeValue(out, elem, path)
		}
		if len(x) == 1 {
			out.WriteByte(',')
		}
		out.WriteByte(')')

	case *Function:
		fmt.Fprintf(out, "<function %s>", x.Name())

	case *Builtin:
		if x.recv != nil {
			fmt.Fprintf(out, "<built-in method %s of %s value>", x.Name(), x.recv.Type())
		} else {
			fmt.Fprintf(out, "<built-in function %s>", x.Name())
		}

	case *Dict:
		out.WriteByte('{')
		if pathContains(path, x) {
			out.WriteString("...") // dict contains itself
		} else {
			sep := ""
			for e := x.ht.head; e != nil; e = e.next {
				k, v := e.key, e.value
				out.WriteString(sep)
				writeValue(out, k, path)
				out.WriteString(": ")
				writeValue(out, v, append(path, x)) // cycle check
				sep = ", "
			}
		}
		out.WriteByte('}')

	case *Set:
		out.WriteString("set([")
		for i, elem := range x.elems() {
			if i > 0 {
				out.WriteString(", ")
			}
			writeValue(out, elem, path)
		}
		out.WriteString("])")

	default:
		out.WriteString(x.String())
	}
}