func (s *Slice) Line() int {
	return s.line
}

func (s *Slice) Col() int {
	// TODO: Col is only called when defining a macro and all it cares about is increasing
	// position to discover whether there is a blank before the parenthesis.
	// We only get here if defining a macro inside a macro.
	// This imperfect implementation means we cannot tell the difference between
	//	#define A #define B(x) x
	// and
	//	#define A #define B (x) x

You only give `Depends` a single parameter.

This parameter must be something like a function.

You **don't call it** directly (don't add the parenthesis at the end), you just pass it as a parameter to `Depends()`.

And that function takes parameters in the same way that *path operation functions* do.

/// tip

Le das a `Depends` un solo parámetro.

Este parámetro debe ser algo como una función.

**No la llames** directamente (no agregues los paréntesis al final), solo pásala como un parámetro a `Depends()`.

Y esa función toma parámetros de la misma manera que las *path operation functions*.

/// tip | Consejo

Você fornece um único parâmetro para `Depends`.

Esse parâmetro deve ser algo como uma função.

Você **não chama a função** diretamente (não adicione os parênteses no final), apenas a passe como parâmetro de `Depends()`.

E essa função vai receber os parâmetros da mesma forma que uma *função de operação de rota*.

/// tip | Dica

		Code:           "ParseExpectedLeftParenAfterCast",
		Description:    "Did not find expected the left parenthesis in the SQL expression.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrParseExpectedLeftParenValueConstructor: {
		Code:           "ParseExpectedLeftParenValueConstructor",
		Description:    "Did not find expected the left parenthesis in the SQL expression.",
		HTTPStatusCode: http.StatusBadRequest,
	},

		tokens = append(tokens, substitution...)
	}
	in.Push(NewSlice(in.Base(), in.Line(), tokens))
}

// argsFor returns a map from formal name to actual value for this argumented macro invocation.
// The opening parenthesis has been absorbed.
func (in *Input) argsFor(macro *Macro) map[string][]Token {
	var args [][]Token
	// One macro argument per iteration. Collect them all and check counts afterwards.
	for argNum := 0; ; argNum++ {

		haveConstant = true
	case '(':
		// Could be parenthesized expression or (R). Must be something, though.
		tok := p.next()
		if tok.ScanToken == scanner.EOF {
			p.errorf("missing right parenthesis")
			return
		}
		rname := tok.String()
		p.back()
		haveConstant = !p.atStartOfRegister(rname)
		if !haveConstant {
			p.back() // Put back the '('.
		}
	}
	if haveConstant {
		p.back()

 * side, this yields nine basic types of ranges, enumerated below. (Notation: a square bracket
 * ({@code [ ]}) indicates that the range is closed on that side; a parenthesis ({@code ( )}) means
 * it is either open or unbounded. The construct {@code {x | statement}} is read "the set of all
 * <i>x</i> such that <i>statement</i>.")
 *
 * <blockquote>
 *
 * <table>