+(define-builtin-markup-command (concat layout props args) (markup-list?)
+ "Concatenate @var{args} in a horizontal line, without spaces inbetween.
+Strings and simple markups are concatenated on the input level, allowing
+ligatures. For example, @code{\\concat @{ \"f\" \\simple #\"i\" @}} is
+equivalent to @code{\"fi\"}."
+
+ (define (concat-string-args arg-list)
+ (fold-right (lambda (arg result-list)
+ (let ((result (if (pair? result-list)
+ (car result-list)
+ '())))
+ (if (and (pair? arg) (eqv? (car arg) simple-markup))
+ (set! arg (cadr arg)))
+ (if (and (string? result) (string? arg))
+ (cons (string-append arg result) (cdr result-list))
+ (cons arg result-list))))
+ '()
+ arg-list))
+
+ (interpret-markup layout
+ (prepend-alist-chain 'word-space 0 props)
+ (make-line-markup (concat-string-args args))))