\ ------ Types ------
-0 constant number-type
+0 constant fixnum-type
1 constant boolean-type
2 constant character-type
3 constant string-type
4 constant nil-type
5 constant pair-type
6 constant symbol-type
+7 constant primitive-type
: istype? ( obj type -- obj bool )
over = ;
: objeq? ( obj obj -- bool )
rot = -rot = and ;
+: 2rot ( a1 a2 b1 b2 c1 c2 -- b1 b2 c1 c2 a1 a2 )
+ >R >R ( a1 a2 b1 b2 )
+ 2swap ( b1 b2 a1 a2 )
+ R> R> ( b1 b2 a1 a2 c1 c2 )
+ 2swap
+;
+
+: -2rot ( a1 a2 b1 b2 c1 c2 -- c1 c2 a1 a2 b1 b2 )
+ 2swap ( a1 a2 c1 c2 b1 b2 )
+ >R >R ( a1 a2 c1 c2 )
+ 2swap ( c1 c2 a1 a2 )
+ R> R>
+;
+
\ }}}
\ ---- Pre-defined symbols ---- {{{
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 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
+;
+
+
: (create-symbol) ( addr n -- symbol-obj )
dup 0= if
2drop nil
\ }}}
+\ ---- Primitives ---- {{{
+
+: make-primitive ( cfa -- )
+ bl word
+ count
+
+ (create-symbol)
+ drop symbol-type
+
+ 2dup
+
+ symbol-table fetchobj
+ cons
+ symbol-table setobj
+
+ rot primitive-type ( var prim )
+ global-env fetchobj define-var
+;
+
+: arg-count-error
+ bold fg red ." Incorrect argument count." reset-term cr
+ abort
+;
+
+: ensure-arg-count ( args n -- )
+ dup 0= if
+ drop nil objeq? false = if
+ arg-count-error
+ then
+ else
+ -rot 2dup nil objeq? if
+ arg-count-error
+ then
+
+ cdr rot 1- recurse
+ 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
+
+\ }}}
+
\ ---- Read ---- {{{
+defer read
+
variable parse-idx
variable stored-parse-idx
create parse-str 161 allot
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] - = ;
-: number? ( -- bool )
- digit? minus? or false = if
- false
- exit
+: plus? ( -- bool )
+ nextchar [char] + = ;
+
+: fixnum? ( -- bool )
+ minus? plus? or if
+ inc-parse-idx
+
+ delim? if
+ dec-parse-idx
+ false exit
+ else
+ dec-parse-idx
+ then
+ else
+ digit? false = if
+ false exit
+ then
then
push-parse-idx
nextchar [char] " = ;
: readnum ( -- num-atom )
- minus? dup if
+ plus? minus? or if
+ minus?
inc-parse-idx
+ else
+ false
then
0
swap if negate then
- number-type
+ fixnum-type
;
: readbool ( -- bool-atom )
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
-;
-
-defer read
-
: readpair ( -- pairobj )
eatspaces
eatspaces
- number? if
+ fixnum? if
readnum
exit
then
: self-evaluating? ( obj -- obj bool )
boolean-type istype? if true exit then
- number-type istype? if true exit then
+ fixnum-type istype? if true exit then
character-type istype? if true exit then
string-type istype? if true exit then
nil-type istype? if true exit then
2swap definition-var 2swap ( env var val )
- >R >R 2swap R> R> 2swap ( var val env )
+ 2rot ( var val env )
define-var
ok-symbol
2swap assignment-var 2swap ( env var val )
- >R >R 2swap R> R> 2swap ( var val env )
+ 2rot ( var val env )
set-var
ok-symbol
then
;
-: true? ( boolobj -- boolean )
+: true? ( boolobj -- bool )
false? invert ;
+: application? ( obj -- obj bool)
+ pair-type istype? ;
+
+: operator ( obj -- operator )
+ car ;
+
+: operands ( obj -- operands )
+ cdr ;
+
+: nooperands? ( operands -- bool )
+ nil objeq? ;
+
+: first-operand ( operands -- operand )
+ car ;
+
+: rest-operands ( operands -- other-operands )
+ cdr ;
+
+: list-of-vals ( args env -- vals )
+ 2swap
+
+ 2dup nooperands? if
+ 2swap 2drop
+ else
+ 2over 2over first-operand 2swap eval
+ -2rot rest-operands 2swap recurse
+ cons
+ then
+;
+
:noname ( obj env -- result )
2swap
2swap ['] eval goto
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
+ exit
+ then
+
bold fg red ." Error evaluating expression - unrecognized type. Aborting." reset-term cr
abort
; is eval
\ ---- Print ---- {{{
+defer print
+
: printnum ( numobj -- ) drop 0 .R ;
: printbool ( numobj -- )
: printnil ( nilobj -- )
2drop ." ()" ;
-defer print
: printpair ( pairobj -- )
2dup
car print
." . " print
;
+: printprim ( primobj -- )
+ 2drop ." <primitive procedure>" ;
+
:noname ( obj -- )
- number-type istype? if printnum exit then
+ fixnum-type istype? if printnum exit then
boolean-type istype? if printbool exit then
character-type istype? if printchar exit then
string-type istype? if printstring 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
bold fg red ." Error printing expression - unrecognized type. Aborting" reset-term cr
abort
The Lambda Lab / projects / scheme.forth.jl.git / blobdiff