Add a \trans command that uses the lam pretty printing.

diff --git a/Core2Core.tex b/Core2Core.tex
index bc385a68324b210e435dbe1f42cbfed975099f8a..1b1a7826577f1418cfc8d4a281dc1e1dc9f24d6e 100644 (file)
--- a/Core2Core.tex
+++ b/Core2Core.tex
@@ -39,6 +39,33 @@
 % Install the lambda calculus pretty-printer, as defined in pret-lam.lua.
 \installprettytype [LAM] [LAM]
 
+% An (invisible) frame to hold a lambda expression
+\define[1]\lamframe{
+        % Put a frame around lambda expressions, so they can have multiple
+        % lines and still appear inline.
+        % The align=right option really does left-alignment, but without the
+        % program will end up on a single line. The strut=no option prevents a
+        % bunch of empty space at the start of the frame.
+        \framed[offset=0mm,location=middle,strut=no,align=right,frame=off]{#1}
+}
+
+\define[2]\trans{
+        % Make \typebuffer uses the LAM pretty printer and a sans-serif font
+        % Also prevent any extra spacing above and below caused by the default
+        % before=\blank and after=\blank.
+        \setuptyping[option=LAM,style=sans,before=,after=]
+        % Prevent the arrow from ending up below the first frame (a \framed
+        % at the start of a line defaults to using vmode).
+        \dontleavehmode
+        % Put the elements in frames, so they can have multiple lines and be
+        % middle-aligned
+        \lamframe{\typebuffer[#1]}
+        \lamframe{\Rightarrow}
+        \lamframe{\typebuffer[#2]}
+        % Reset the typing settings to their defaults
+        \setuptyping[option=none,style=\tttf]
+}
+
 % A helper to print a single example in the half the page width. The example
 % text should be in a buffer whose name is given in an argument.
 %