4 constant nil-type
5 constant pair-type
6 constant symbol-type
-7 constant primitive-type
+7 constant primitive-proc-type
+8 constant compound-proc-type
: istype? ( obj type -- obj bool )
over = ;
: type@ ( objvar -- type ) 1+ @ ;
: value! ( newval objvar -- ) ! ;
: type! ( newtype objvar -- ) 1+ ! ;
-: setobj ( newobj objvar -- ) dup rot swap 1+ ! ! ;
-: fetchobj ( objvar -- obj ) dup @ swap 1+ @ ;
+: obj! ( newobj objvar -- ) dup rot swap 1+ ! ! ;
+: obj@ ( objvar -- obj ) dup @ swap 1+ @ ;
: objeq? ( obj obj -- bool )
rot = -rot = and ;
objvar symbol-table
+: duplicate-charlist ( charlist -- copy )
+ 2dup nil objeq? false = if
+ 2dup car 2swap cdr recurse cons
+ then ;
+
+: charlist-equiv ( charlist charlist -- bool )
+
+ 2over 2over
+
+ \ One or both nil
+ nil? -rot 2drop
+ if
+ nil? -rot 2drop
+ if
+ 2drop 2drop true exit
+ else
+ 2drop 2drop false exit
+ then
+ else
+ nil? -rot 2drop
+ if
+ 2drop 2drop false exit
+ then
+ then
+
+ 2over 2over
+
+ \ Neither nil
+ car drop -rot car drop = if
+ cdr 2swap cdr recurse
+ else
+ 2drop 2drop false
+ then
+;
+
+: charlist>symbol ( charlist -- symbol-obj )
+
+ symbol-table obj@
+
+ begin
+ nil? false =
+ while
+ 2over 2over
+ car drop pair-type
+ charlist-equiv if
+ 2swap 2drop
+ car
+ exit
+ else
+ cdr
+ then
+ repeat
+
+ 2drop
+ drop symbol-type 2dup
+ symbol-table obj@ cons
+ symbol-table obj!
+;
+
+
: (create-symbol) ( addr n -- symbol-obj )
dup 0= if
2drop nil
2dup
- symbol-table fetchobj
+ symbol-table obj@
cons
- symbol-table setobj
+ symbol-table obj!
create swap , ,
does> dup @ swap 1+ @
create-symbol set! set!-symbol
create-symbol ok ok-symbol
create-symbol if if-symbol
+create-symbol lambda lambda-symbol
+create-symbol λ λ-symbol
\ }}}
objvar vals
: get-vars-vals-frame ( var frame -- bool )
- 2dup frame-vars vars setobj
- frame-vals vals setobj
+ 2dup frame-vars vars obj!
+ frame-vals vals obj!
begin
- vars fetchobj nil objeq? false =
+ vars obj@ nil objeq? false =
while
- 2dup vars fetchobj car objeq? if
+ 2dup vars obj@ car objeq? if
2drop true
exit
then
- vars fetchobj cdr vars setobj
- vals fetchobj cdr vals setobj
+ vars obj@ cdr vars obj!
+ vals obj@ cdr vals obj!
repeat
2drop false
2over 2over first-frame
get-vars-vals-frame if
2drop 2drop
- vars fetchobj vals fetchobj true
+ vars obj@ vals obj@ true
exit
then
objvar env
: define-var ( var val env -- )
- env setobj
+ env obj!
- 2over env fetchobj ( var val var env )
+ 2over env obj@ ( var val var env )
get-vars-vals if
2swap 2drop ( var val vals )
set-car!
2drop
else
- env fetchobj
+ env obj@
first-frame ( var val frame )
add-binding
then
objvar global-env
nil nil nil extend-env
-global-env setobj
+global-env obj!
\ }}}
2dup
- symbol-table fetchobj
+ symbol-table obj@
cons
- symbol-table setobj
+ symbol-table obj!
- rot primitive-type ( var prim )
- global-env fetchobj define-var
+ rot primitive-proc-type ( var prim )
+ global-env obj@ define-var
;
: arg-count-error
then
;
+: arg-type-error
+ bold fg red ." Incorrect argument type." reset-term cr
+ abort
+;
+
+: ensure-arg-type ( arg type -- arg )
+ istype? false = if
+ arg-type-error
+ then
+;
+
include scheme-primitives.4th
\ }}}
nextchar [char] ) = or
;
+: commentstart? ( -- bool )
+ nextchar [char] ; = ;
+
: eatspaces
+
+ false \ Indicates whether or not we're eating a comment
+
begin
- whitespace?
+ dup whitespace? or commentstart? or
while
+ dup nextchar '\n' = and if
+ invert \ Stop eating comment
+ else
+ dup false = commentstart? and if
+ invert \ Begin eating comment
+ then
+ then
+
inc-parse-idx
repeat
+ drop
;
: digit? ( -- bool )
: minus? ( -- bool )
nextchar [char] - = ;
+: plus? ( -- bool )
+ nextchar [char] + = ;
+
: fixnum? ( -- bool )
- minus? if
+ minus? plus? or if
inc-parse-idx
delim? if
nextchar [char] " = ;
: readnum ( -- num-atom )
- minus? dup if
+ plus? minus? or if
+ minus?
inc-parse-idx
+ else
+ false
then
0
cons
;
-: charlist-equiv ( charlist charlist -- bool )
-
- 2over 2over
-
- \ One or both nil
- nil? -rot 2drop
- if
- nil? -rot 2drop
- if
- 2drop 2drop true exit
- else
- 2drop 2drop false exit
- then
- else
- nil? -rot 2drop
- if
- 2drop 2drop false exit
- then
- then
-
- 2over 2over
-
- \ Neither nil
- car drop -rot car drop = if
- cdr 2swap cdr recurse
- else
- 2drop 2drop false
- then
-;
-
-: charlist>symbol ( charlist -- symbol-obj )
-
- symbol-table fetchobj
-
- begin
- nil? false =
- while
- 2over 2over
- car drop pair-type
- charlist-equiv if
- 2swap 2drop
- car
- exit
- else
- cdr
- then
- repeat
-
- 2drop
- drop symbol-type 2dup
- symbol-table fetchobj cons
- symbol-table setobj
-;
-
: readpair ( -- pairobj )
eatspaces
then
eof? if
+ inc-parse-idx
bold fg blue ." Moriturus te saluto." reset-term ." ok" cr
quit
then
\ Anything else is parsed as a symbol
readsymbol charlist>symbol
+ \ Replace λ with lambda
+ 2dup λ-symbol objeq? if
+ 2drop lambda-symbol
+ then
+
+
; is read
\ }}}
: true? ( boolobj -- bool )
false? invert ;
+: lambda? ( obj -- obj bool )
+ lambda-symbol tagged-list? ;
+
+: lambda-parameters ( obj -- params )
+ cdr car ;
+
+: lambda-body ( obj -- body )
+ cdr cdr ;
+
+: make-procedure ( params body env -- proc )
+ nil
+ cons cons cons
+ drop compound-proc-type
+;
+
: application? ( obj -- obj bool)
pair-type istype? ;
then
;
+: apply ( proc args )
+ 2swap dup case
+ primitive-proc-type of
+ drop execute
+ endof
+
+ compound-proc-type of
+ ." Compound procedures not yet implemented."
+ endof
+
+ bold fg red ." Object not applicable. Aboring." reset-term cr
+ abort
+ endcase
+;
+
:noname ( obj env -- result )
2swap
2swap ['] eval goto
then
+ lambda? if
+ 2dup lambda-body
+ 2swap lambda-parameters
+ 2rot make-procedure
+ exit
+ then
+
application? if
2over 2over
operator 2swap eval
-
- primitive-type istype? false = if
- bold fg red ." Object not applicable. Aboring." reset-term cr
- abort
- then
-
-2rot
operands 2swap list-of-vals
- 2swap drop execute
+ apply
exit
then
: printprim ( primobj -- )
2drop ." <primitive procedure>" ;
+: printcomp ( primobj -- )
+ 2drop ." <compound procedure>" ;
+
:noname ( obj -- )
fixnum-type istype? if printnum exit then
boolean-type istype? if printbool exit then
symbol-type istype? if printsymbol exit then
nil-type istype? if printnil exit then
pair-type istype? if ." (" printpair ." )" exit then
- primitive-type istype? if printprim exit then
+ primitive-proc-type istype? if printprim exit then
+ compound-proc-type istype? if printcomp exit then
bold fg red ." Error printing expression - unrecognized type. Aborting" reset-term cr
abort
begin
cr bold fg green ." > " reset-term
read
- global-env fetchobj eval
+ global-env obj@ eval
fg cyan ." ; " print reset-term
again
;
The Lambda Lab / projects / scheme.forth.jl.git / blobdiff