--- /dev/null
+\ Decompilation
+
+
+: CLOSESTLINK ( addr vcfa -- lfa )
+
+ vocab>latest dup ( addr link link )
+ rot dup -rot ( link addr link addr )
+ < if
+ 2drop
+ 0 exit
+ then
+
+ swap ( addr link )
+ 0 -rot ( 0 addr link )
+
+ begin
+ rot drop ( addr link )
+ dup -rot @ ( link addr nextlink )
+ 2dup ( link addr nextlink addr nextlink)
+ > until
+
+ 2drop
+;
+
+: MIN ( n m -- max )
+ 2dup - 0> if
+ swap drop
+ else
+ drop
+ then
+;
+
+: BODYLEN ( cfa -- len )
+
+ here swap ( clink addr )
+ context dup #context @ + swap
+ do
+ dup i @
+
+ closestlink ( clink addr clink' )
+
+ ?dup 0> if
+ rot min
+ swap
+ then
+ loop
+
+ -
+;
+
+: ?IMMEDIATE
+ 1+ ( skip over the link pointer )
+ @ ( get the flags/length byte )
+ F_IMMED AND ( mask the F_IMMED flag and return it (as a truth value) )
+;
+
+: SEE
+ BL WORD FIND ( find the dictionary entry to decompile )
+
+ CR
+
+ 0= IF
+ ." Word '" COUNT TYPE ." ' not found in dictionary."
+ CR ABORT
+ THEN
+
+ DUP DUP BODYLEN + SWAP >LINK
+
+ DUP LINK> @ CASE
+ DOCOL OF
+ \ Colon definition
+ [CHAR] : EMIT SPACE DUP 1+ .NAME SPACE
+ DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR
+ ENDOF
+ DOVAR OF
+ \ Variable definition
+ ." Variable " DUP 1+ .NAME CR
+ 2DROP EXIT
+ ENDOF
+ DOCON OF
+ \ Constant definition
+ ." Constant " DUP 1+ .NAME CR
+ 2DROP EXIT
+ ENDOF
+
+ \ Unknown codeword
+ ." Primitive or word with unrecognized codeword." CR
+ DROP 2DROP EXIT
+ ENDCASE
+
+ 4 SPACES
+
+ LINK> >BODY ( get the data address, ie. points after DOCOL | end-of-word start-of-data )
+
+ ( now we start decompiling until we hit the end of the word )
+ BEGIN ( end start )
+ 2DUP >
+ WHILE
+ DUP @ ( end start codeword )
+
+ CASE
+ ['] LIT OF ( is it LIT ? )
+ 1+ DUP @ ( get next word which is the integer constant )
+ . ( and print it )
+ ENDOF
+ ['] LITSTRING OF ( is it LITSTRING ? )
+ [CHAR] S EMIT [CHAR] " EMIT SPACE ( print S"<space> )
+ 1+ DUP @ ( get the length word )
+ SWAP 1+ SWAP ( end start+1 length )
+ 2DUP TYPE ( print the string )
+ [CHAR] " EMIT SPACE ( finish the string with a final quote )
+ + ( end start+1+len, aligned )
+ 1- ( because we're about to add 4 below )
+ ENDOF
+ ['] 0BRANCH OF ( is it 0BRANCH ? )
+ ." 0BRANCH ( "
+ 1+ DUP @ ( print the offset )
+ .
+ ." ) "
+ ENDOF
+ ['] BRANCH OF ( is it BRANCH ? )
+ ." BRANCH ( "
+ 1+ DUP @ ( print the offset )
+ .
+ ." ) "
+ ENDOF
+ ['] ['] OF ( is it ['] ? )
+ ." ['] "
+ 1+ DUP @ ( get the next codeword )
+ >NAME ( and force it to be printed as a dictionary entry )
+ .NAME SPACE
+ ENDOF
+ ['] EXIT OF ( is it EXIT? )
+ ( We expect the last word to be EXIT, and if it is then we don't print it
+ because EXIT is normally implied by ;. EXIT can also appear in the middle
+ of words, and then it needs to be printed. )
+ 2DUP ( end start end start )
+ 1+ ( end start end start+1 )
+ <> IF ( end start | we're not at the end )
+ ." EXIT "
+ THEN
+ ENDOF
+ ( default case: )
+ DUP ( in the default case we always need to DUP before using )
+ >NAME ( look up the codeword to get the dictionary entry )
+ .NAME SPACE ( and print it )
+ ENDCASE
+
+ 1+ ( end start+1 )
+ REPEAT
+
+ [CHAR] ; EMIT CR
+
+ 2DROP ( restore stack )
+;
+