Add .4TH Forth extension.

lib/linguist/languages.yml

@@ -918,6 +918,7 @@ Forth:
   color: "#341708"
   extensions:
   - .fth
+  - .4TH
   - .4th
   - .F
   - .f

samples/Forth/tools.4TH

@@ -0,0 +1,133 @@
+\ -*- forth -*- Copyright 2004, 2013 Lars Brinkhoff
+
+( Tools words. )
+
+: .s ( -- )
+    [char] < emit  depth (.)  ." > "
+    'SP @ >r r@ depth 1- cells +
+    begin
+	dup r@ <>
+    while
+	dup @ .
+	/cell -
+    repeat r> 2drop ;
+
+: ?   @ . ;
+
+: c?   c@ . ;
+
+: dump   bounds do i ? /cell +loop cr ;
+
+: cdump   bounds do i c? loop cr ;
+
+: again   postpone branch , ; immediate
+
+: see-find ( caddr -- end xt )
+    >r here lastxt @
+    begin
+	dup 0= abort" Undefined word"
+	dup r@ word= if r> drop exit then
+	nip dup >nextxt
+    again ;
+
+: cabs ( char -- |char| )   dup 127 > if 256 swap - then ;
+
+: xt. ( xt -- )
+    ( >name ) count cabs type ;
+
+: xt? ( xt -- flag )
+    >r lastxt @ begin
+	?dup
+    while
+	dup r@ = if r> 2drop -1 exit then
+	>nextxt
+    repeat r> drop 0 ;
+
+: disassemble ( x -- )
+    dup xt? if
+        ( >name ) count
+        dup 127 > if ." postpone " then
+        cabs type
+    else
+        .
+    then ;
+
+: .addr  dup . ;
+
+: see-line ( addr -- )
+    cr ."     ( " .addr ." ) "  @ disassemble ;
+
+: see-word ( end xt -- )
+    >r ." : " r@ xt.
+    r@ >body do i see-line /cell +loop
+    ."  ;" r> c@ 127 > if ."  immediate" then ;
+
+: see   bl word see-find see-word cr ;
+
+: #body   bl word see-find >body - ;
+
+: type-word ( end xt -- flag )
+    xt. space drop 0 ;
+
+: traverse-dictionary ( in.. xt -- out.. )
+    \ xt execution: ( in.. end xt2 -- in.. 0 | in.. end xt2 -- out.. true )
+    >r  here lastxt @  begin
+	?dup
+    while
+	r> 2dup >r >r execute
+	if r> r> 2drop exit then
+	r> dup >nextxt
+    repeat r> 2drop ;
+
+: words ( -- )
+    ['] type-word traverse-dictionary cr ;
+
+\ ----------------------------------------------------------------------
+
+( Tools extension words. )
+
+\ ;code
+
+\ assembler
+
+\ in kernel: bye
+
+\ code
+
+\ cs-pick
+
+\ cs-roll
+
+\ editor
+
+: forget   ' dup >nextxt lastxt !  'here !  reveal ;
+
+\ Kernel: state
+
+\ [else]
+
+\ [if]
+
+\ [then]
+
+\ ----------------------------------------------------------------------
+
+( Forth2012 tools extension words. )
+
+\ TODO: n>r
+
+\ TODO: nr>
+
+\ TODO: synonym
+
+: [undefined]   bl-word find nip 0= ; immediate
+
+: [defined]   postpone [undefined] invert ; immediate
+
+\ ----------------------------------------------------------------------
+
+: @+ ( addr -- addr+/cell x )   dup cell+ swap @ ;
+
+: !+ ( x addr -- addr+/cell )   tuck ! cell+ ;
+
+: -rot   swap >r swap r> ;