: definition-val ( obj -- val )
cdr cdr car ;
-: eval-definition ( obj env -- res )
- 2swap
- 2over 2over
- definition-val 2swap
- eval
-
- 2swap definition-var 2swap
-
- 2rot
- define-var
-
- ok-symbol
-;
-
: assignment? ( obj -- obj bool )
set!-symbol tagged-list? ;
: assignment-val ( obj -- val )
cdr cdr car ;
-: eval-assignment ( obj env -- res )
- 2swap
- 2over 2over ( env obj env obj )
- assignment-val 2swap ( env obj valexp env )
- eval ( env obj val )
-
- 2swap assignment-var 2swap ( env var val )
-
- 2rot ( var val env )
- set-var
-
- ok-symbol
-;
-
: macro-definition? ( obj -- obj bool )
define-macro-symbol tagged-list? ;
: macro-definition-body ( exp -- body )
cdr cdr ;
-objvar env
-: eval-define-macro ( obj env -- res )
- env obj!
-
- 2dup macro-definition-name 2swap ( name obj )
- 2dup macro-definition-params 2swap ( name params obj )
- macro-definition-body ( name params body )
-
- env obj@ ( name params body env )
-
- make-macro
-
- ok-symbol
-;
-hide env
-
: if? ( obj -- obj bool )
if-symbol tagged-list? ;
: lambda-body ( obj -- body )
cdr cdr ;
-: eval-sequence ( explist env -- finalexp env )
- ( Evaluates all bar the final expressions in
- an an expression list. The final expression
- is returned to allow for tail optimization. )
-
- 2swap ( env explist )
-
- \ Abort on empty list
- nil? if
- 2drop none
- 2swap exit
- then
-
- begin
- 2dup cdr ( env explist nextexplist )
- nil? false =
- while
- -2rot car 2over ( nextexplist env exp env )
- eval
- 2drop \ discard result
- 2swap ( env nextexplist )
- repeat
-
- 2drop car 2swap ( finalexp env )
-;
-
: application? ( obj -- obj bool )
pair-type istype? ;
: 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
-;
-
: procedure-params ( proc -- params )
drop pair-type car ;
2swap
;
-: apply ( proc argvals -- result )
- 2swap dup case
- primitive-proc-type of
- drop execute
- endof
-
- compound-proc-type of
- 2dup procedure-body ( argvals proc body )
- -2rot 2dup procedure-params ( body argvals proc argnames )
- -2rot procedure-env ( body argnames argvals procenv )
-
- -2rot 2swap
- flatten-proc-args
- 2swap 2rot
-
- extend-env ( body env )
-
- eval-sequence
-
- R> drop ['] eval goto-deferred \ Tail call optimization
- endof
-
- except-message: ." object '" drop print ." ' not applicable." recoverable-exception throw
- endcase
-;
-
-:noname ( obj env -- result )
- 2swap
-
- \ --- DEBUG ---
- (
- fg yellow ." Evaluating: " bold 2dup print reset-term
- space fg green ." PS: " bold depth . reset-term
- space fg blue ." RS: " bold RSP@ RSP0 - . reset-term cr
- )
-
- self-evaluating? if
- 2swap 2drop
- exit
- then
-
- quote? if
- quote-body
- 2swap 2drop
- exit
- then
-
- variable? if
- 2swap lookup-var
- exit
- then
-
- definition? if
- 2swap eval-definition
- exit
- then
-
- assignment? if
- 2swap eval-assignment
- exit
- then
-
- macro-definition? if
- 2swap eval-define-macro
- exit
- then
-
- if? if
- 2over 2over
- if-predicate
- 2swap eval
-
- true? if
- if-consequent
- else
- if-alternative
- then
-
- 2swap
- ['] eval goto-deferred
- then
-
- lambda? if
- 2dup lambda-parameters
- 2swap lambda-body
- 2rot make-procedure
- exit
- then
-
- application? if
-
- 2over 2over ( env exp env exp )
- operator ( env exp env opname )
-
- 2swap eval ( env exp proc )
-
- -2rot ( proc env exp )
- operands 2swap ( proc operands env )
- list-of-vals ( proc argvals )
-
- apply
- exit
- then
-
- except-message: ." tried to evaluate object with unknown type." recoverable-exception throw
-; is eval
-
\ }}}
\ ---- Analyze ----
\ Final element of eproc list is primitive procedure
drop \ dump type signifier
- .s cr \ DEBUG
-
goto \ jump straight to primitive procedure (executor)
;
nil cons cons cons
;
-: if-executor ( cproc aproc pproc env -- res )
- 2swap 2over ( cproc aproc env pproc env -- res )
- evaluate-eproc
-
- true? if
- 2swap 2drop
- else
- 2rot 2drop
- then
-
- evaluate-eproc
-;
-
-: analyze-if ( exp -- eproc )
- 2dup if-predicate analyze
- 2swap 2dup if-consequent analyze
- 2swap if-alternative analyze
-
- ['] if-executor primitive-proc-type
- nil cons cons cons cons
-;
-
: sequence-executor ( eproc-list env -- res )
2swap
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 )
nil cons cons
;
+
+: macro-definition-executor ( name params bproc env -- ok )
+ make-macro ok-symbol
+;
+
+: analyze-macro-definition ( exp -- eproc )
+ 2dup macro-definition-name
+ 2swap 2dup macro-definition-params
+ 2swap macro-definition-body analyze-sequence
+
+ ['] macro-definition-executor primitive-proc-type
+ nil cons cons cons cons
+;
+
+: if-executor ( cproc aproc pproc env -- res )
+ 2swap 2over ( cproc aproc env pproc env -- res )
+ evaluate-eproc
+
+ true? if
+ 2swap 2drop
+ else
+ 2rot 2drop
+ then
+
+ ['] evaluate-eproc goto
+;
+
+: analyze-if ( exp -- eproc )
+ 2dup if-consequent analyze
+ 2swap 2dup if-alternative analyze
+ 2swap if-predicate analyze
+
+ ['] if-executor primitive-proc-type
+ nil cons cons cons cons
+;
+
: lambda-executor ( params bproc env -- res )
make-procedure
( Although this is packaged up as a regular compound procedure,
endof
compound-proc-type of
- 2dup procedure-body ( argvals proc body )
+ 2dup procedure-body ( argvals proc bproc )
-2rot 2dup procedure-params ( bproc argvals proc argnames )
-2rot procedure-env ( bproc argnames argvals procenv )
:noname ( exp --- eproc )
- self-evaluating? if
- analyze-self-evaluating
- exit
- then
+ self-evaluating? if analyze-self-evaluating exit then
- quote? if
- analyze-quoted
- exit
- then
+ quote? if analyze-quoted exit then
- variable? if
- analyze-variable
- exit
- then
+ variable? if analyze-variable exit then
- definition? if
- analyze-definition
- exit
- then
+ definition? if analyze-definition exit then
- assignment? if
- analyze-assignment
- exit
- then
+ assignment? if analyze-assignment exit then
- if? if
- analyze-if
- exit
- then
+ macro-definition? if analyze-macro-definition exit then
- lambda? if
- analyze-lambda
- exit
- then
+ if? if analyze-if exit then
- application? if
- analyze-application
- 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
( Simply evaluates the given procedure with expbody as its argument. )
: macro-eval ( proc expbody -- result )
2swap
- 2dup procedure-body ( expbody proc procbody )
- -2rot 2dup procedure-params ( procbody expbody proc argnames )
- -2rot procedure-env ( procbody argnames expbody procenv )
+ 2dup procedure-body ( expbody proc bproc )
+ -2rot 2dup procedure-params ( bproc expbody proc argnames )
+ -2rot procedure-env ( bproc argnames expbody procenv )
-2rot 2swap
flatten-proc-args
2swap 2rot
- extend-env eval-sequence eval
+ extend-env ( bproc env )
+
+ ['] evaluate-eproc goto
;
: expand-macro ( exp -- result )
pair-type istype? invert if exit then
+
2dup car symbol-type istype? invert if 2drop exit then
-
- lookup-macro nil? if
- 2drop exit then
+
+ lookup-macro nil? if 2drop exit then
2over cdr macro-eval
\ }}}
+:noname ( exp env -- res )
+ 2swap expand analyze 2swap evaluate-eproc
+; is eval
+
\ ---- Print ---- {{{
: printfixnum ( fixnum -- ) drop 0 .R ;
2swap 2drop ( port obj )
- expand
-
global-env obj@ eval ( port res )
again
;
include scheme-primitives.4th
- \ s" scheme-library.scm" load 2drop
+ s" scheme-library.scm" load 2drop
\ }}}
true exit
then
- expand
-
global-env obj@ eval
fg cyan ." ; " print reset-term
enable-gc
\ Display welcome message
- \ welcome-symbol nil cons global-env obj@ eval 2drop
+ welcome-symbol nil cons global-env obj@ eval 2drop
begin
['] repl-body catch
The Lambda Lab / projects / scheme.forth.jl.git / blobdiff