eq: Added `limit' and `combinations'.

* src/guile/skribilo/package/eq.scm (%operators): Added `limit' and
  `combinations'.
  (eq:limit): New.
  (eq:combinations): New.
  (eq:limit): New text-based writer.
  (eq:combinations): Likewise.

* src/guile/skribilo/package/eq/lout.scm (eq:limit): New.
  (eq:combinations): New.

git-archimport-id: skribilo@sv.gnu.org--2006/skribilo--devo--1.2--patch-24

2 files changed, 63 insertions, 1 deletions

diff --git a/src/guile/skribilo/package/eq.scm b/src/guile/skribilo/package/eq.scm
index 58fb77c..c45f698 100644
--- a/src/guile/skribilo/package/eq.scm
+++ b/src/guile/skribilo/package/eq.scm
@@ -54,7 +54,7 @@
 
 (define %operators
   '(/ * + - = != ~= < > <= >= sqrt expt sum product script
-    in notin apply))
+    in notin apply limit combinations))
 
 (define %symbols
   ;; A set of symbols that are automatically recognized within an `eq' quoted
@@ -264,6 +264,22 @@ a symbol representing the mathematical operator denoted by @var{m} (e.g.,
 			 (loop (cdr body) (cons first result)))))))))
 
 
+(define-markup (eq:limit var lim :rest body :key (ident #f))
+  (new markup
+       (markup 'eq:limit)
+       (ident (or ident (symbol->string (gensym "eq:limit"))))
+       (options `((:var ,var) (:limit ,lim)
+                  ,@(the-options body :ident)))
+       (body (the-body body))))
+
+(define-markup (eq:combinations x y :rest opts :key (ident #f))
+  (new markup
+       (markup 'eq:combinations)
+       (ident (or ident (symbol->string (gensym "eq:combinations"))))
+       (options `((:of ,x) (:among ,y)
+                  ,@(the-options opts :ident)))
+       (body (the-body opts))))
+
 
 ;;;
 ;;; Text-based rendering.
@@ -434,6 +450,28 @@ a symbol representing the mathematical operator denoted by @var{m} (e.g.,
 	       (output (sup sup*) engine)
 	       (output (sub sub*) engine))))
 
+(markup-writer 'eq:limit (find-engine 'base)
+   :action (lambda (node engine)
+             (let ((body  (markup-body node))
+                   (var   (markup-option node :var))
+                   (limit (markup-option node :limit)))
+               (display "lim (")
+               (output var engine)
+               (output (symbol "->") engine)
+               (output limit engine)
+               (display ", ")
+               (output body engine)
+               (display ")"))))
+
+(markup-writer 'eq:combinations (find-engine 'base)
+   :action (lambda (node engine)
+             (let ((of    (markup-option node :of))
+                   (among (markup-option node :among)))
+               (display "combinations(")
+               (output of engine)
+               (display ", ")
+               (output among engine)
+               (display ")"))))
 
 
 
diff --git a/src/guile/skribilo/package/eq/lout.scm b/src/guile/skribilo/package/eq/lout.scm
index cce5124..563fdbf 100644
--- a/src/guile/skribilo/package/eq/lout.scm
+++ b/src/guile/skribilo/package/eq/lout.scm
@@ -191,6 +191,30 @@
 	       (display ")"))))
 
 
+(markup-writer 'eq:limit (find-engine 'lout)
+   :action (lambda (node engine)
+             (let ((body  (markup-body node))
+                   (var   (markup-option node :var))
+                   (limit (markup-option node :limit)))
+               (display "{ lim on { ")
+               (output var engine)
+               (display " --> ")
+               (output limit engine)
+               (display " } } (")
+               (output body engine)
+               (display ") "))))
+
+(markup-writer 'eq:combinations (find-engine 'lout)
+   :action (lambda (node engine)
+             (let ((of    (markup-option node :of))
+                   (among (markup-option node :among)))
+               (display " { matrix atleft { blpar } atright { brpar } { ")
+               (display "row col { ")
+               (output among engine)
+               (display " } row col { ")
+               (output of engine)
+               (display " } } }\n"))))
+
 
 ;;;
 ;;; Sums, products, integrals, etc.