 : read-chunk ( -- byte-array/f )
     4 ensured-read [ 4 ensured-read* dup le> ensured-read* 3append ] [ f ] if* ;
 : read-riff-chunk ( -- byte-array/f )
-    "riff-chunk" heap-size ensured-read* ;
+    riff-chunk heap-size ensured-read* ;
 
 : id= ( chunk id -- ? )
-    [ 4 head ] dip sequence= ;
+    [ 4 head ] dip sequence= ; inline
 
-: check-chunk ( chunk id min-size -- ? )
-    [ id= ] [ [ length ] dip >= ] bi-curry* bi and ;
+: check-chunk ( chunk id class -- ? )
+    heap-size [ id= ] [ [ length ] dip >= ] bi-curry* bi and ;
 
 :: read-wav-chunks ( -- fmt data )
     f :> fmt! f :> data!
     [ { [ fmt data and not ] [ read-chunk ] } 0&& dup ]
     [ {
-        { [ dup FMT-MAGIC  "wav-fmt-chunk"  heap-size check-chunk ] [ fmt!  ] }
-        { [ dup DATA-MAGIC "wav-data-chunk" heap-size check-chunk ] [ data! ] }
+        { [ dup FMT-MAGIC  wav-fmt-chunk  check-chunk ] [ wav-fmt-chunk  memory>struct fmt!  ] }
+        { [ dup DATA-MAGIC wav-data-chunk check-chunk ] [ wav-data-chunk memory>struct data! ] }
     } cond ] while drop
     fmt data 2dup and [ invalid-wav-file ] unless ;
 
 : verify-wav ( chunk -- )
     {
         [ RIFF-MAGIC id= ]
-        [ riff-chunk-format 4 memory>byte-array WAVE-MAGIC id= ]
+        [ riff-chunk memory>struct format>> 4 memory>byte-array WAVE-MAGIC id= ]
     } 1&&
     [ invalid-wav-file ] unless ;
 
 : (read-wav) ( -- audio )
     read-wav-chunks
     [
-        [ wav-fmt-chunk-num-channels    2 memory>byte-array le> ]
-        [ wav-fmt-chunk-bits-per-sample 2 memory>byte-array le> ]
-        [ wav-fmt-chunk-sample-rate     4 memory>byte-array le> ] tri
+        [ num-channels>>    2 memory>byte-array le> ]
+        [ bits-per-sample>> 2 memory>byte-array le> ]
+        [ sample-rate>>     4 memory>byte-array le> ] tri
     ] [
-        [ riff-chunk-header-size 4 memory>byte-array le> dup ]
-        [ wav-data-chunk-body ] bi swap memory>byte-array
+        [ header>> size>> 4 memory>byte-array le> dup ]
+        [ body>> >c-ptr ] bi swap memory>byte-array
     ] bi* <audio> ;
 
 : read-wav ( filename -- audio )

USING: alien.c-types alien.syntax audio combinators
combinators.short-circuit io io.binary io.encodings.binary
io.files io.streams.byte-array kernel locals math
sequences alien.data ;
IN: audio.wav

CONSTANT: RIFF-MAGIC "RIFF"

CONSTANT: FMT-MAGIC  "fmt "
CONSTANT: DATA-MAGIC "data"

STRUCT: riff-chunk-header
    { id char[4] }
    { size char[4] } ;

STRUCT: riff-chunk
    { header riff-chunk-header }
    { format char[4] } ;

STRUCT: wav-fmt-chunk
    { header riff-chunk-header }
    { audio-format uchar[2] }
    { num-channels uchar[2] }
    { sample-rate uchar[4] }
    { byte-rate uchar[4] }
    { block-align uchar[2] }
    { bits-per-sample uchar[2] } ;

STRUCT: wav-data-chunk
    { header riff-chunk-header }
    { body uchar[0] } ;

ERROR: invalid-wav-file ;

