\stopframedtext
}
+% Install the lambda calculus pretty-printer, as defined in pret-lam.lua.
+\installprettytype [LAM] [LAM]
+
+\definetyping[lambda][option=LAM,style=sans]
+
+% 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.
%
\item More builtin expressions should be added and these should be evaluated
by the compiler. For example, map, fold, +.
\stopitemize
+
+Initial example
+
+\startlambda
+ λx.
+ let s = foo x
+ in
+ case s of
+ (a, b) ->
+ case a of
+ High -> add
+ Low -> let
+ op' = case b of
+ High -> sub
+ Low -> λc.λd.c
+ in
+ λc.λd.op' d c
+\stoplambda
+
+After top-level η-abstraction:
+
+\startlambda
+ λx.λc.λd.
+ (let s = foo x
+ in
+ case s of
+ (a, b) ->
+ case a of
+ High -> add
+ Low -> let
+ op' = case b of
+ High -> sub
+ Low -> λc.λd.c
+ in
+ λc.λd.op' d c
+ ) c d
+\stoplambda
+
+After (extended) β-reduction:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ in
+ case s of
+ (a, b) ->
+ case a of
+ High -> add c d
+ Low -> let
+ op' = case b of
+ High -> sub
+ Low -> λc.λd.c
+ in
+ op' d c
+\stoplambda
+
+After return value extraction:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ r = case s of
+ (a, b) ->
+ case a of
+ High -> add c d
+ Low -> let
+ op' = case b of
+ High -> sub
+ Low -> λc.λd.c
+ in
+ op' d c
+ in
+ r
+\stoplambda
+
+Scrutinee simplification does not apply.
+
+After case binder wildening:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = case s of (_, _) ->
+ case a of
+ High -> add c d
+ Low -> let op' = case b of
+ High -> sub
+ Low -> λc.λd.c
+ in
+ op' d c
+ in
+ r
+\stoplambda
+
+After case value simplification
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = case s of (_, _) -> r'
+ rh = add c d
+ rl = let rll = λc.λd.c
+ op' = case b of
+ High -> sub
+ Low -> rll
+ in
+ op' d c
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r
+\stoplambda
+
+After let flattening:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = case s of (_, _) -> r'
+ rh = add c d
+ rl = op' d c
+ rll = λc.λd.c
+ op' = case b of
+ High -> sub
+ Low -> rll
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r
+\stoplambda
+
+After function inlining:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = case s of (_, _) -> r'
+ rh = add c d
+ rl = (case b of
+ High -> sub
+ Low -> λc.λd.c) d c
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r
+\stoplambda
+
+After (extended) β-reduction again:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = case s of (_, _) -> r'
+ rh = add c d
+ rl = case b of
+ High -> sub d c
+ Low -> d
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r
+\stoplambda
+
+After case value simplification again:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = case s of (_, _) -> r'
+ rh = add c d
+ rlh = sub d c
+ rl = case b of
+ High -> rlh
+ Low -> d
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r
+\stoplambda
+
+After case removal:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ r = r'
+ rh = add c d
+ rlh = sub d c
+ rl = case b of
+ High -> rlh
+ Low -> d
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r
+\stoplambda
+
+After let bind removal:
+
+\startlambda
+ λx.λc.λd.
+ let s = foo x
+ a = case s of (a, _) -> a
+ b = case s of (_, b) -> b
+ rh = add c d
+ rlh = sub d c
+ rl = case b of
+ High -> rlh
+ Low -> d
+ r' = case a of
+ High -> rh
+ Low -> rl
+ in
+ r'
+\stoplambda
+
+Application simplification is not applicable.
\stoptext
projects / matthijs / master-project / report.git / blobdiff