\ ---- Analyze ----
-: evaluate-eproc ( env eproc --- res )
+: evaluate-eproc ( eproc env --- res )
+
+ >R >R
+
begin
nil? invert
while
2drop \ get rid of null
+ R> R>
+
\ Final element of eproc list is primitive procedure
drop \ dump type signifier
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
;
-: sequential-executor ( env eproc1 eproc2 -- res )
- 2swap 2 2pick 2swap ( env eproc2 env eproc1 )
- evaluate-eproc 2drop
- evaluate-eproc
+: 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 )
- nil? if
- except-message: ." Tried to analyze empty expression sequence." recoverable-exception throw
- then
+
+: (analyze-sequence) ( explist -- eproc-list )
+ nil? if exit then
2dup car analyze
- 2swap cdr
- nil? if
- 2drop
- else
- recurse
- ['] sequential-executor
- nil cons cons
- then
+ 2swap cdr recurse
+
+ cons
;
-: lambda-executor ( env params bproc -- res )
- 2rot make-procedure
+: 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
: analyze-lambda ( exp -- eproc )
2dup lambda-parameters
- 2swap lambda-body analyze-sequence
+ 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? invert if
+ 2over 2over car evaluate-eproc ( env aprocs thisres )
+ -rot cdr recurse
+;
+
+: application-executor ( operator-proc arg-procs env -- res )
+ 2rot 2over ( aprocs env fproc env )
+ evaluate-eproc ( aprocs env proc )
+ 2swap -2rot 2over 2swap ( proc env env aprocs )
+ evaluate-operand-eprocs ( proc env vals )
+
+ 2rot ( env vals proc )
+
+ dup case
+ primitive-proc-type of
+ 2rot 2drop 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
+ nil cons cons cons
+;
+
:noname ( exp --- eproc )
self-evaluating? if