Merge branch 'master' of git://factorcode.org/git/factor

diff --combined basis/struct-arrays/struct-arrays.factor
index a378754590596f7b131679c3facf51aae4634bf8,390a03455d75d63066bf4f30fc2a56a17993f7f8..53815c7da4f052b0f7b4570eff9e91b53b9253c2
--- 1/basis/struct-arrays/struct-arrays.factor
--- 2/basis/struct-arrays/struct-arrays.factor
+++ b/basis/struct-arrays/struct-arrays.factor
@@@ -1,7 -1,8 +1,8 @@@
  ! Copyright (C) 2008 Slava Pestov.
  ! See http://factorcode.org/license.txt for BSD license.
  USING: accessors alien alien.c-types alien.structs byte-arrays
- classes.struct kernel libc math parser sequences sequences.private ;
+ classes.struct kernel libc math parser sequences
+ sequences.private words fry memoize compiler.units ;
  IN: struct-arrays
  
  : c-type-struct-class ( c-type -- class )
@@@ -11,7 -12,8 +12,8 @@@ TUPLE: struct-arra
  { underlying c-ptr read-only }
  { length array-capacity read-only }
  { element-size array-capacity read-only }
- { class read-only } ;
+ { class read-only }
+ { ctor read-only } ;
  
  M: struct-array length length>> ; inline
  M: struct-array byte-length [ length>> ] [ element-size>> ] bi * ; inline
@@@ -20,38 -22,50 +22,53 @@@
      [ element-size>> * >fixnum ] [ underlying>> ] bi <displaced-alien> ; inline
  
  M: struct-array nth-unsafe
-     [ (nth-ptr) ] [ class>> dup struct-class? ] bi [ memory>struct ] [ drop ] if ; inline
+     [ (nth-ptr) ] [ ctor>> ] bi execute( alien -- object ) ; inline
  
  M: struct-array set-nth-unsafe
      [ (nth-ptr) swap ] [ element-size>> ] bi memcpy ; inline
  
+ : (struct-element-constructor) ( c-type -- word )
+     [
+         "struct-array-ctor" f <word>
+         [
+             swap dup struct-class?
+             [ '[ _ memory>struct ] [ ] like ] [ drop [ ] ] if
+             (( alien -- object )) define-inline
+         ] keep
+     ] with-compilation-unit ;
+ 
+ ! Foldable memo word. This is an optimization; by precompiling a
+ ! constructor for array elements, we avoid memory>struct's slow path.
+ MEMO: struct-element-constructor ( c-type -- word )
+     (struct-element-constructor) ; foldable
+ 
+ : <direct-struct-array> ( alien length c-type -- struct-array )
+     [ heap-size ] [ c-type-struct-class ] [ struct-element-constructor ]
+     tri struct-array boa ; inline
+ 
  M: struct-array new-sequence
-     [ element-size>> [ * (byte-array) ] 2keep ]
-     [ class>> ] bi struct-array boa ; inline
+     [ element-size>> * (byte-array) ] [ length>> ] [ class>> ] tri
+     <direct-struct-array> ; inline
  
  M: struct-array resize ( n seq -- newseq )
-     [ [ element-size>> * ] [ underlying>> ] bi resize ]
-     [ [ element-size>> ] [ class>> ] bi ] 2bi
-     struct-array boa ;
+     [ [ element-size>> * ] [ underlying>> ] bi resize ] [ class>> ] 2bi
+     <direct-struct-array> ; inline
  
  : <struct-array> ( length c-type -- struct-array )
-     [ heap-size [ * <byte-array> ] 2keep ]
-     [ c-type-struct-class ] bi struct-array boa ; inline
+     [ heap-size * <byte-array> ] 2keep <direct-struct-array> ; inline
  
  ERROR: bad-byte-array-length byte-array ;
  
  : byte-array>struct-array ( byte-array c-type -- struct-array )
-     [ heap-size [
+     [
+         heap-size
          [ dup length ] dip /mod 0 =
          [ drop bad-byte-array-length ] unless
-     ] keep ] [ c-type-struct-class ] bi struct-array boa ; inline
- 
- : <direct-struct-array> ( alien length c-type -- struct-array )
-     [ heap-size ] [ c-type-struct-class ] bi struct-array boa ; inline
+     ] keep <direct-struct-array> ; inline
  
 +: struct-array-on ( struct length -- struct-array )
 +    [ [ >c-ptr ] [ class ] bi ] dip swap <direct-struct-array> ; inline    
 +
  : malloc-struct-array ( length c-type -- struct-array )
      [ heap-size calloc ] 2keep <direct-struct-array> ; inline