: quote-body ( quote-obj -- quote-body-obj )
cdr car ;
-: quasiquote? ( obj -- obj bool )
- quasiquote-symbol tagged-list? ;
-
-: unquote? ( obj -- obj bool )
- unquote-symbol tagged-list? ;
-
-: unquote-splicing? ( obj -- obj bool )
- unquote-splicing-symbol tagged-list? ;
-
-: eval-unquote ( env obj -- res )
- cdr ( env args )
-
- nil? if
- except-message: ." no arguments to unquote." recoverable-exception throw
- then
-
- 2dup cdr
- nil? false = if
- except-message: ." too many arguments to unquote." recoverable-exception throw
- then
-
- 2drop car 2swap eval
-;
-
-( Create a new list from elements of l1 consed on to l2 )
-: join-lists ( l2 l1 -- l3 )
- nil? if 2drop exit then
-
- 2dup car
- -2rot cdr
- recurse cons
-;
-
-defer eval-quasiquote-item
-: eval-quasiquote-pair ( env obj -- res )
- 2over 2over ( env obj env obj )
-
- cdr eval-quasiquote-item
-
- -2rot car ( cdritem env objcar )
-
- unquote-splicing? if
- eval-unquote ( cdritems caritem )
-
- 2swap nil? if
- 2drop
- else
- 2swap join-lists
- then
- else
- eval-quasiquote-item ( cdritems caritem )
- 2swap cons
- then
-
-;
-
-:noname ( env obj )
- nil? if
- 2swap 2drop exit
- then
-
- unquote? if
- eval-unquote exit
- then
-
- pair-type istype? if
- eval-quasiquote-pair exit
- then
-
- 2swap 2drop
-; is eval-quasiquote-item
-
-: eval-quasiquote ( obj env -- res )
- 2swap cdr ( env args )
-
- nil? if
- except-message: ." no arguments to quasiquote." recoverable-exception throw
- then
-
- 2dup cdr ( env args args-cdr )
- nil? false = if
- except-message: ." too many arguments to quasiquote." recoverable-exception throw
- then
-
- 2drop car ( env arg )
-
- eval-quasiquote-item
-;
-
: variable? ( obj -- obj bool )
symbol-type istype? ;
exit
then
- quasiquote? if
- 2swap eval-quasiquote
- exit
- then
-
variable? if
2swap lookup-var
exit
\ ---- Analyze ----
-: evaluate-eproc ( env eproc --- res )
+: evaluate-eproc ( eproc env --- res )
+
+ >R >R
+
begin
nil? invert
while
2drop \ get rid of null
+ R> R> 2swap
+
\ Final element of eproc list is primitive procedure
drop \ dump type signifier
+
+ .s cr \ DEBUG
+
goto \ jump straight to primitive procedure (executor)
;
-: self-evaluating-executor ( env exp -- exp )
- 2swap 2drop ;
+: self-evaluating-executor ( exp env -- exp )
+ 2drop ;
: analyze-self-evaluating ( exp --- eproc )
['] self-evaluating-executor primitive-proc-type
nil cons cons
;
-: quote-executor ( env exp -- exp )
- 2swap 2drop ;
+: quote-executor ( exp env -- exp )
+ 2drop ;
: analyze-quoted ( exp -- eproc )
quote-body
nil cons cons
;
-: variable-executor ( env var -- val )
- 2swap lookup-var ;
+: variable-executor ( var env -- val )
+ lookup-var ;
: analyze-variable ( exp -- eproc )
['] variable-executor primitive-proc-type
nil cons cons
;
-: definition-executor ( env var val-eproc -- ok )
- 2rot 2dup 2rot ( var env env val-eproc )
+: definition-executor ( var val-eproc env -- ok )
+ 2swap 2over ( var env val-eproc env )
evaluate-eproc 2swap ( var val env )
define-var
ok-symbol
nil cons cons cons
;
-: assignment-executor ( env var val-eproc -- ok )
- 2rot 2dup 2rot ( var env env val-eproc )
+: assignment-executor ( var val-eproc env -- ok )
+ 2swap 2over ( var env val-eproc env )
evaluate-eproc 2swap ( var val env )
set-var
ok-symbol
nil cons cons cons
;
-: if-executor ( env pproc cproc aproc -- res )
- 2rot 3 2pick 2swap ( env cproc aproc env pproc )
+: if-executor ( cproc aproc pproc env -- res )
+ 2swap 2over ( cproc aproc env pproc env -- res )
evaluate-eproc
+
true? if
- 2drop evaluate-eproc
+ 2swap 2drop
else
- 2swap 2drop evaluate-eproc
+ 2rot 2drop
then
+
+ evaluate-eproc
;
: analyze-if ( exp -- eproc )
nil cons cons cons cons
;
+: sequence-executor ( eproc-list env -- res )
+ 2swap
+
+ begin
+ 2dup cdr ( env elist elist-rest)
+ nil? invert
+ while
+
+ -2rot car 2over ( elist-rest env elist-head env )
+ evaluate-eproc ( elist-rest env head-res )
+ 2drop 2swap ( env elist-rest )
+ repeat
+
+ 2drop car 2swap
+ ['] evaluate-eproc goto
+;
+
+
+: (analyze-sequence) ( explist -- eproc-list )
+ nil? if exit then
+
+ 2dup car analyze
+ 2swap cdr recurse
+
+ cons
+;
+
+: analyze-sequence ( explist -- eproc )
+ (analyze-sequence)
+ ['] sequence-executor primitive-proc-type
+ nil cons cons
+;
+
+: lambda-executor ( params bproc env -- res )
+ make-procedure
+ ( Although this is packaged up as a regular compound procedure,
+ the "body" element contains an _eproc_ to be evaluated in an
+ environment resulting from extending env with the parameter
+ bindings. )
+;
+
+: analyze-lambda ( exp -- eproc )
+ 2dup lambda-parameters
+ 2swap lambda-body
+
+ nil? if
+ except-message: ." encountered lambda with an empty body." recoverable-exception throw
+ then
+
+ analyze-sequence
+
+ ['] lambda-executor primitive-proc-type
+ nil cons cons cons
+;
+
+: operand-eproc-list ( operands -- eprocs )
+ nil? invert if
+ 2dup car analyze
+ 2swap cdr recurse
+ cons
+ then
+;
+
+: evaluate-operand-eprocs ( env aprocs -- vals )
+ nil? if
+ 2swap 2drop
+ else
+ 2over 2over car 2swap evaluate-eproc ( env aprocs thisval )
+ -2rot cdr recurse ( thisval restvals )
+ cons
+ then
+;
+
+: application-executor ( operator-proc arg-procs env -- res )
+ 2rot 2over ( aprocs env fproc env )
+ evaluate-eproc ( aprocs env proc )
+
+ -2rot 2swap ( proc env aprocs )
+ evaluate-operand-eprocs ( proc vals )
+
+ 2swap ( vals proc )
+
+ dup case
+ primitive-proc-type of
+ drop execute
+ endof
+
+ compound-proc-type of
+ 2dup procedure-body ( argvals proc body )
+ -2rot 2dup procedure-params ( bproc argvals proc argnames )
+ -2rot procedure-env ( bproc argnames argvals procenv )
+
+ -2rot 2swap
+ flatten-proc-args
+ 2swap 2rot
+
+ extend-env ( bproc env )
+
+ ['] evaluate-eproc goto
+ endof
+
+ except-message: ." object '" drop print ." ' not applicable." recoverable-exception throw
+ endcase
+;
+
+: analyze-application ( exp -- eproc )
+ 2dup operator analyze
+ 2swap operands operand-eproc-list
+
+ ['] application-executor primitive-proc-type
+ nil cons cons cons
+;
+
:noname ( exp --- eproc )
self-evaluating? if
exit
then
+ lambda? if
+ analyze-lambda
+ exit
+ then
+
+ application? if
+ analyze-application
+ exit
+ then
+
+
+ except-message: ." tried to analyze unknown expression type." recoverable-exception throw
+
; is analyze
R> drop ['] expand goto-deferred
;
-: expand-quasiquote-item ( exp -- result )
- nil? if exit then
-
- unquote? if
- unquote-symbol 2swap cdr car expand nil cons cons
- exit
- then
-
- unquote-splicing? if
- unquote-splicing-symbol 2swap cdr car expand nil cons cons
- exit
- then
-
- pair-type istype? if
- 2dup car recurse
- 2swap cdr recurse
- cons
- then
-;
-
-: expand-quasiquote ( exp -- result )
- quasiquote-symbol 2swap cdr
-
- expand-quasiquote-item
-
- cons ;
-
: expand-definition ( exp -- result )
define-symbol 2swap
quote? if exit then
- quasiquote? if expand-quasiquote exit then
-
definition? if expand-definition exit then
assignment? if expand-assignment exit then