h3	Literal text replacement using "{...}"
	Literal text replacement, Literal replacement, text replacement, replacement
p.i	since version 4.2.6: in macros
	since version 4.4.6: everywhere

p	Before a source line is assembled, expressions between "{" and "}" are resolved.

p	Literal text replacement is typically used to create calculated label names and can solve a common problem with macros.

pre	mx = 0	; a counter which serves as a seed for labels in all macros
	;
	.macro extend_sign	; a macro with a forward jump
		ld	h,0
		ld	a,l
		add	a
		jr	nc,L{mx}	; jump forward
		dec	h
	L{mx}:
	mx = mx+1			; next use of macro will use next number
	.endm

p	While backward jumps in labels can simply use a redefinable label to jump to, this is not possible with forward jumps. Besides other solutions (you could create a <tt>.local</tt> context in your macro) you can generate label names using a counter. In the above example the first use of the macro would use label <tt>L0</tt>, the second <tt>L1</tt> and so on.

p	You can also iterate over a range of programmatically named labels:

pre	_n = 0
	.rept mx
		.dw	L{_n}
	_n = _n +1
	.endm

p	This will generate an array with all addresses where label <tt>L{mx}</tt> in the above example was used.
	Actually you can implement arrays of labels this way e.g. to automatically create jump tables.