2008-12-07 Gabriel Dos Reis <gdr@cs.tamu.edu>

	* interp/g-opt.boot ($simpleVMoperators): New.
	(isSimpleVMForm): Likewise.
	(isFloatableVMForm): Likewise.
	(optLET): Likewise.  Expand backend let-forms.
	* interp/c-util.boot (foldSpadcall): Look into LET and COND forms.
	(replaceSimpleFunctions): Likewise.
	(mutateCONDFormWithUnaryFunction): New.
	(mutateLETFormWithUnaryFunction): Likewise.
	* interp/compiler.boot (tryCourtesyCoercion): Split from coerce.
	(compRetractAlternative): Simplify. Now try courtesy coercions
	before retraction.  
	(compRecoverAlternative): New.
	(compMatch): Simplify.  Implement type recovery too.

2008-12-06  Gabriel Dos Reis  <gdr@cs.tamu.edu>

	* interp/compiler.boot (compRetractAlternative): New.
	(compMatch): Likewise.  Use it to implement pattern macthing
	for retractable domains.
	* interp/parse.boot (parseAtAt): New.
	* interp/postpar.boot (postAtAt): Likewise.
	(postAlternatives): Likewise.
	(postMatch): Likewise.
	* interp/metalex.lisp (Keywords): Remove `otherwise' as keyword.
	* interp/fnewmeta.lisp (|PARSE-Match|): New local parser.
	* interp/newaux.lisp (@@): New token.  Align wih interpreter.
	(otherwise): Remove binding specification.
	(case): Now also a Nud token.

1 files changed, 29 insertions, 0 deletions

diff --git a/src/interp/postpar.boot b/src/interp/postpar.boot
index 7706a257..c045ffc7 100644
--- a/src/interp/postpar.boot
+++ b/src/interp/postpar.boot
@@ -35,6 +35,8 @@
 import macros
 namespace BOOT
 
+module postpar
+
 ++ The type of parse trees.
 %ParseTree <=> 
   %Number or %Symbol or %String or cons
@@ -141,6 +143,11 @@ postPretend t ==
   t isnt ["pretend",x,y] => systemErrorHere "postPretend"
   ["pretend",postTran x,:postType y]
 
+postAtAt: %ParseTree -> %ParseForm
+postAtAt t ==
+  t isnt ["@@",x,y] => systemErrorHere "postAtAt"
+  ["@@",postTran x,:postType y]
+
 postConstruct: %ParseTree -> %ParseForm
 postConstruct u ==
   u is ["construct",b] =>
@@ -578,6 +585,26 @@ postBootNotEqual u ==
    '"is not valid Spad.  Please use",:bright '"~=",'"instead."]
   ["~=",:postTran rest u]
 
+
+--% %Match
+
+postAlternatives alts ==
+    alts is ["%Block",:cases] => ["%Block",:[tranAlt c for c in cases]]
+    tranAlt alts
+  where
+    tranAlt c ==
+      c is ["=>",pred,conseq] => 
+        ["=>",postTran pred,postTran conseq]
+      postTran c
+
+postMatch: %ParseTree -> %ParseForm
+postMatch t ==
+  t isnt ["%Match",expr,alts] => systemErrorHere "postMatch"
+  alts :=
+    alts is [";",:.] => ["%Block",:postFlattenLeft(alts,";")]
+    alts
+  ["%Match",postTran expr, postAlternatives alts]
+
 --% Register special parse tree tranformers.
 
 for x in [["with", :"postWith"],_
@@ -600,6 +627,7 @@ for x in [["with", :"postWith"],_
 	  [":", :"postColon"],_
 	  ["@", :"postAtSign"],_
 	  ["pretend", :"postPretend"],_
+          ["@@",:"postAtAt"],_
 	  ["if", :"postIf"],_
 	  ["Join", :"postJoin"],_
 	  ["%Signature", :"postSignature"],_
@@ -608,6 +636,7 @@ for x in [["with", :"postWith"],_
 	  ["==>", :"postMDef"],_
 	  ["->", :"postMapping"],_
 	  ["=>", :"postExit"],_
+          ["%Match",:"postMatch"],_
           ["^=", :"postBootNotEqual"],_
 	  ["%Comma", :"post%Comma"]] repeat
   MAKEPROP(first x, "postTran", rest x)