`eq' package: Added support for Lout's new `eq2'.

* src/guile/skribilo/package/eq.scm (*use-lout-eq2?*): New.
  (direct-equation-child?): New.

* src/guile/skribilo/package/eq/lout.scm (Initialization): Use `eq2' if
  asked to.
  (simple-lout-markup-writer): Use `direct-equation-child?' to decide on
  whether the issue the `^' character.  This is to avoid issuing too many
  `^', which could result in broken layout.
  (eq:limit): Adapated.
  (range-lout-markup-writer): Likewise.

git-archimport-id: skribilo@sv.gnu.org--2006/skribilo--devo--1.2--patch-89

2 files changed, 30 insertions, 5 deletions

diff --git a/src/guile/skribilo/package/eq.scm b/src/guile/skribilo/package/eq.scm
index 8b4d325..90db17b 100644
--- a/src/guile/skribilo/package/eq.scm
+++ b/src/guile/skribilo/package/eq.scm
@@ -60,6 +60,11 @@
   ;; native engine.
   (make-parameter #f))
 
+(define-public *use-lout-eq2?*
+  ;; Whether the use the new Lout `eq2' package instead of `eq'.
+  (make-parameter #f))
+
+
 (define %operators
   '(/ * + - = != ~= < > <= >= sqrt expt sum product script
     in notin apply limit combinations set))
@@ -130,6 +135,16 @@ a symbol representing the mathematical operator denoted by @var{m} (e.g.,
            ((#t) #t)
            (else #f)))))
 
+(define-public (direct-equation-child? m)
+  "Return @code{#t} if @var{m} is a direct child of an @code{eq} markup."
+  (let ((parent (ast-parent m)))
+    (and (is-markup? parent 'eq)
+         (let ((body (markup-body parent)))
+           (or (eq? body m)
+               (and (list? body)
+                    (memq m body)))))))
+
+
 
 ;;;
 ;;; Operator precedence.
diff --git a/src/guile/skribilo/package/eq/lout.scm b/src/guile/skribilo/package/eq/lout.scm
index d0d9570..bd4ccc7 100644
--- a/src/guile/skribilo/package/eq/lout.scm
+++ b/src/guile/skribilo/package/eq/lout.scm
@@ -45,7 +45,9 @@
 	;; Append the `eq' include file
 	(engine-custom-set! lout 'includes
 			    (string-append includes "\n"
-					   "@SysInclude { eq }\n")))))
+					   "@SysInclude { "
+                                           (if (*use-lout-eq2?*) "eq2" "eq")
+                                           " }\n")))))
 
 
 ;;;
@@ -131,7 +133,8 @@
                                   (and first?
                                        (is-markup? eq-parent 'eq-display)
                                        (eq? ',sym
-                                            (markup-option eq :align-with))))
+                                            (markup-option eq :align-with))
+                                       (direct-equation-child? node)))
                                  (op (car operands))
                                  (eq-op? (equation-markup? op))
                                  (need-paren?
@@ -232,9 +235,12 @@
              (let ((body  (markup-body node))
                    (var   (markup-option node :var))
                    (limit (markup-option node :limit)))
-               (display "{ lim from { ")
+               (format #t "{ lim ~a { { "
+                       (if (*use-lout-eq2?*)
+                           "atop @SubScriptStyle"
+                           "from"))
                (output var engine)
-               (display " --> ")
+               (display " } --> ")
                (output limit engine)
                (display (string-append " } } @VContract { " %left-paren))
                (output body engine)
@@ -262,7 +268,11 @@
 		(let ((from (markup-option node :from))
 		      (to (markup-option node :to))
 		      (body (markup-body node)))
-		  (display ,(string-append " { big " lout-name
+		  (display ,(string-append " { "
+                                           (if (*use-lout-eq2?*)
+                                               ""
+                                               "big ")
+                                           lout-name
 					   " from { "))
 		  (output from engine)
 		  (display " } to { ")