include debugging.4th
defer read
+defer expand
defer eval
defer print
make-type symbol-type
make-type primitive-proc-type
make-type compound-proc-type
-make-type fileport-type
+make-type port-type
: istype? ( obj type -- obj bool )
over = ;
1 nextexception +!
does> @ ;
-make-exception recoverable-exception
-make-exception unrecoverable-exception
-
-: display-exception-msg ( addr count -- )
+: except-message:
bold fg red
." Exception: "
- type
- reset-term ;
-
-: throw" immediate
- [compile] s"
+;
- ['] rot , ['] dup ,
+make-exception recoverable-exception
+make-exception unrecoverable-exception
- [compile] if
- ['] -rot ,
- ['] display-exception-msg ,
- [compile] then
-
- ['] throw ,
-;
+: throw reset-term throw ;
\ }}}
\ ---- List-structured memory ---- {{{
-10000 constant scheme-memsize
+20000 constant scheme-memsize
create car-cells scheme-memsize allot
create car-type-cells scheme-memsize allot
then
nextfree @ scheme-memsize >= if
- unrecoverable-exception throw s" Out of memory!"
+ except-message: ." Out of memory!" unrecoverable-exception throw
then
;
\ }}}
-\ ---- Port I/O ---- {{{
-
-: fileport>fid ( fileport -- fid )
- drop ;
-
-: fid>fileport ( fid -- fileport )
- fileport-type ;
-
-: open-input-file ( addr n -- fileport )
- r/o open-file drop fid>fileport
-;
-
-: close-port ( fileport -- )
- fileport>fid close-file drop
-;
-
-objvar console-i/o-port
-0 fileport-type console-i/o-port obj!
-
-objvar current-input-port
-console-i/o-port obj@ current-input-port obj!
-
-: read-port ( fileport -- obj )
- current-input-port obj!
- read ;
-
-: read-console ( -- obj )
- console-i/o-port obj@ read-port ;
-
-\ }}}
-
\ ---- Pre-defined symbols ---- {{{
objvar symbol-table
create-symbol if if-symbol
create-symbol lambda lambda-symbol
create-symbol λ λ-symbol
-create-symbol begin begin-symbol
+create-symbol eof eof-symbol
+create-symbol no-match no-match-symbol
\ Symbol to be bound to welcome message procedure by library
create-symbol welcome welcome-symbol
\ }}}
+\ ---- Port I/O ---- {{{
+
+( Ports are pairs with the fid in the car and the peek buffer in the cdr. )
+
+: fileport>fid ( fileport -- fid )
+ drop pair-type car drop ;
+
+: get-last-peek ( fileport -- char/nil )
+ drop pair-type cdr ;
+
+: set-last-peek ( char/nil fileport -- )
+ drop pair-type set-cdr!
+;
+
+: fid>fileport ( fid -- fileport )
+ fixnum-type nil cons drop port-type ;
+
+: open-input-file ( addr n -- fileport )
+ r/o open-file drop fid>fileport
+;
+
+: close-port ( fileport -- )
+ fileport>fid close-file drop
+;
+
+objvar console-i/o-port
+0 fixnum-type nil cons drop port-type console-i/o-port obj!
+
+objvar current-input-port
+console-i/o-port obj@ current-input-port obj!
+
+: read-char ( port -- char )
+ 2dup get-last-peek nil? if
+ 2drop
+ 2dup console-i/o-port obj@ objeq? if
+ 2drop
+ key character-type
+ else
+ fileport>fid pad 1 rot read-file 0= if
+ eof-symbol
+ else
+ pad @ character-type
+ then
+ then
+ else
+ nil 2rot set-cdr!
+ then
+;
+
+: peek-char ( port -- char )
+ 2dup get-last-peek nil? if
+ 2drop 2dup read-char
+ 2dup 2rot set-last-peek
+ else
+ 2swap 2drop
+ then
+;
+
+variable read-line-buffer-span
+variable read-line-buffer-offset
+
+( Hack to save original read-line while we transition to new one. )
+: orig-read-line immediate
+ ['] read-line , ;
+
+: read-line ( port -- string )
+
+ 2dup get-last-peek
+ nil? if
+ 2drop
+ 0 read-line-buffer-offset !
+ else
+ 2over nil 2swap set-last-peek
+ 2dup drop '\n' = if
+ 2drop nil nil cons exit
+ else
+ drop pad !
+ 1 read-line-buffer-offset !
+ then
+ then
+
+ 2dup console-i/o-port obj@ objeq? if
+ 2drop
+ pad read-line-buffer-offset @ + 200 expect cr
+ span @ read-line-buffer-offset @ + read-line-buffer-span !
+ else
+ pad read-line-buffer-offset @ + 200 2over fileport>fid orig-read-line
+ drop swap read-line-buffer-offset @ + read-line-buffer-span !
+ then
+
+ nil
+
+ begin
+ read-line-buffer-span @ 0>
+ while
+ pad read-line-buffer-span @ 1- + @ character-type 2swap cons
+ -1 read-line-buffer-span +!
+ repeat
+
+ nil? if
+ nil cons drop string-type
+ else
+ drop string-type
+ then
+;
+
+: read-port ( fileport -- obj )
+ current-input-port obj!
+ read ;
+
+: read-console ( -- obj )
+ console-i/o-port obj@ read-port ;
+
+\ }}}
+
\ ---- Environments ---- {{{
: enclosing-env ( env -- env )
hide vars
hide vals
+objvar var
+
: lookup-var ( var env -- val )
+ 2over var obj!
get-vars-vals if
2swap 2drop car
else
- recoverable-exception throw" Tried to read unbound variable."
+ except-message: ." tried to read unbound variable '" var obj@ print ." '." recoverable-exception throw
then
;
: set-var ( var val env -- )
>R >R 2swap R> R> ( val var env )
+ 2over var obj!
get-vars-vals if
2swap 2drop ( val vals )
set-car!
else
- recoverable-exception throw" Tried to set unbound variable."
+ except-message: ." tried to set unbound variable '" var obj@ print ." '." recoverable-exception throw
then
;
+hide var
+
objvar env
: define-var ( var val env -- )
: ensure-arg-count ( args n -- )
dup 0= if
drop nil objeq? false = if
- recoverable-exception throw" Too many arguments for primitive procedure."
+ except-message: ." Too many arguments for primitive procedure." recoverable-exception throw
then
else
-rot nil? if
- recoverable-exception throw" Too few arguments for primitive procedure."
+ except-message: ." Too few arguments for primitive procedure." recoverable-exception throw
then
cdr rot 1- recurse
: ensure-arg-type-and-count ( tn tn-1 ... t2 t1 args n -- )
dup 0= if
drop nil objeq? false = if
- recoverable-exception throw" Too many arguments for primitive procedure."
+ except-message: ." Too many arguments for primitive procedure." recoverable-exception throw
then
else
-rot nil? if
- recoverable-exception throw" Too few arguments for primitive procedure."
+ except-message: ." Too few arguments for primitive procedure." recoverable-exception throw
then
2dup cdr 2swap car ( ... t1 n args' arg1 )
2rot 1- swap 2swap rot ( ... args' n-1 arg1 t1 )
istype? false = if
- recoverable-exception throw" Incorrect type for primitive procedure."
+ except-message: ." Incorrect type for primitive procedure." recoverable-exception throw
then
2drop recurse
: ensure-arg-type ( arg type -- arg )
istype? false = if
- recoverable-exception throw" Incorrect argument type for primitive procedure."
+ except-message: ." Incorrect argument type for primitive procedure." recoverable-exception throw
then
;
( Look up macro in macro table. Returns nil if
no macro is found. )
: lookup-macro ( name_symbol -- proc )
+
+ symbol-type istype? invert if
+ \ Early exit if argument is not a symbol
+ 2drop nil exit
+ then
+
macro-table obj@
begin
parse-str 160 expect cr
span @ parse-str-span !
else
- parse-str 160 current-input-port obj@ fileport>fid read-line
+ parse-str 160 current-input-port obj@ fileport>fid orig-read-line
drop swap parse-str-span !
parse-str-span @ 0= and if append-eof then
cdr ( env args )
nil? if
- recoverable-exception throw" no arguments to unquote."
+ except-message: ." no arguments to unquote." recoverable-exception throw
then
2dup cdr
nil? false = if
- recoverable-exception throw" too many arguments to unquote."
+ except-message: ." too many arguments to unquote." recoverable-exception throw
then
2drop car 2swap eval
2swap cdr ( env args )
nil? if
- recoverable-exception throw" no arguments to quasiquote."
+ except-message: ." no arguments to quasiquote." recoverable-exception throw
then
2dup cdr ( env args args-cdr )
nil? false = if
- recoverable-exception throw" too many arguments to quasiquote."
+ except-message: ." too many arguments to quasiquote." recoverable-exception throw
then
2drop car ( env arg )
: definition? ( obj -- obj bool )
define-symbol tagged-list? ;
-: make-lambda ( params body -- lambda-exp )
- lambda-symbol -2rot cons cons ;
-
-( Handles iterative expansion of defines in
- terms of nested lambdas. Most Schemes only
- handle one iteration of expansion! )
-: definition-var-val ( obj -- var val )
-
- cdr 2dup cdr 2swap car ( val var )
-
- begin
- symbol-type istype? false =
- while
- 2dup cdr 2swap car ( val formals var' )
- -2rot 2swap ( var' formals val )
- make-lambda nil cons ( var' val' )
- 2swap ( val' var' )
- repeat
+: definition-var ( obj -- var )
+ cdr car ;
- 2swap car
-;
+: definition-val ( obj -- val )
+ cdr cdr car ;
: eval-definition ( obj env -- res )
- 2dup 2rot ( env env obj )
- definition-var-val ( env env var val )
- 2rot eval ( env var val )
+ 2swap
+ 2over 2over
+ definition-val 2swap
+ eval
- 2rot ( var val env )
+ 2swap definition-var 2swap
+
+ 2rot
define-var
ok-symbol
: lambda-body ( obj -- body )
cdr cdr ;
-: begin? ( obj -- obj bool )
- begin-symbol tagged-list? ;
-
-: begin-actions ( obj -- actions )
- cdr ;
-
: eval-sequence ( explist env -- finalexp env )
( Evaluates all bar the final expressions in
an an expression list. The final expression
: flatten-proc-args ( argvals argnames -- argvals' argnames' )
nil? if
2over nil? false = if
- recoverable-exception throw" Too many arguments for compound procedure."
+ except-message: ." Too many arguments for compound procedure." recoverable-exception throw
else
2drop
then
2over
nil? if
- recoverable-exception throw" Too few arguments for compound procedure."
+ except-message: ." Too few arguments for compound procedure." recoverable-exception throw
else
cdr
then
R> drop ['] eval goto-deferred \ Tail call optimization
endof
- recoverable-exception throw" Object not applicable."
+ except-message: ." object '" drop print ." ' not applicable." recoverable-exception throw
endcase
;
-( Simply evaluates the given procedure with expbody as its argument. )
-: macro-expand ( 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 )
-
- -2rot 2swap
- flatten-proc-args
- 2swap 2rot
-
- extend-env eval-sequence eval
-;
-
: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
exit
then
- begin? if
- begin-actions 2swap
- eval-sequence
- ['] eval goto-deferred
- then
-
application? if
2over 2over ( env exp env exp )
operator ( env exp env opname )
- 2dup lookup-macro nil? false = if
- \ Macro function evaluation
+ 2swap eval ( env exp proc )
- ( env exp env opname mproc )
- 2swap 2drop -2rot 2drop cdr ( env mproc body )
+ -2rot ( proc env exp )
+ operands 2swap ( proc operands env )
+ list-of-vals ( proc argvals )
- macro-expand
+ apply
+ exit
+ then
- 2swap
- ['] eval goto-deferred
- else
- \ Regular function application
+ except-message: ." tried to evaluate object with unknown type." recoverable-exception throw
+; is eval
- 2drop ( env exp env opname )
+\ }}}
- 2swap eval ( env exp proc )
+\ ---- Macro Expansion ---- {{{
- -2rot ( proc env exp )
- operands 2swap ( proc operands env )
- list-of-vals ( proc argvals )
+( 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 )
+
+ -2rot 2swap
+ flatten-proc-args
+ 2swap 2rot
- apply
- exit
- then
+ extend-env eval-sequence eval
+;
+
+: 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
+
+ 2over cdr macro-eval
+
+ 2dup no-match-symbol objeq? if
+ 2drop exit
+ else
+ 2swap 2drop
then
- recoverable-exception throw" Tried to evaluate object with unknown type."
-; is eval
+ 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
+
+ 2dup definition-var
+ 2swap definition-val expand
+ nil ( define var val' nil )
+
+ cons cons cons ;
+
+: expand-assignment ( exp -- result )
+ set!-symbol 2swap
+
+ 2dup assignment-var
+ 2swap assignment-val expand
+ nil ( define var val' nil )
+
+ cons cons cons ;
+
+: expand-list ( exp -- res )
+ nil? if exit then
+
+ 2dup car expand
+ 2swap cdr recurse
+
+ cons ;
+
+: macro-definition-nameparams
+ cdr car ;
+
+: expand-define-macro ( exp -- res )
+ define-macro-symbol 2swap
+ 2dup macro-definition-nameparams
+ 2swap macro-definition-body expand-list
+
+ cons cons ;
+
+: expand-lambda ( exp -- res )
+ lambda-symbol 2swap
+ 2dup lambda-parameters
+ 2swap lambda-body expand-list
+
+ cons cons ;
+
+: expand-if ( exp -- res )
+ if-symbol 2swap
+
+ 2dup if-predicate expand
+ 2swap 2dup if-consequent expand
+ 2swap if-alternative none? if
+ 2drop nil
+ else
+ expand nil cons
+ then
+
+ cons cons cons ;
+
+: expand-application ( exp -- res )
+ 2dup operator expand
+ 2swap operands expand-list
+
+ cons ;
+
+:noname ( exp -- result )
+ expand-macro
+
+ self-evaluating? if exit then
+
+ quote? if exit then
+
+ quasiquote? if expand-quasiquote exit then
+
+ definition? if expand-definition exit then
+
+ assignment? if expand-assignment exit then
+
+ macro-definition? if expand-define-macro exit then
+
+ lambda? if expand-lambda exit then
+
+ if? if expand-if exit then
+
+ application? if expand-application exit then
+
+; is expand
\ }}}
primitive-proc-type istype? if printprim exit then
compound-proc-type istype? if printcomp exit then
none-type istype? if printnone exit then
+ port-type istype? if printport exit then
- recoverable-exception throw" Tried to print object with unknown type."
+ except-message: ." tried to print object with unknown type." recoverable-exception throw
; is print
\ }}}
string-type istype? if true exit then
symbol-type istype? if true exit then
compound-proc-type istype? if true exit then
+ port-type istype? if true exit then
false
;
symbol-table obj@ gc-mark-obj
macro-table obj@ gc-mark-obj
+ console-i/o-port obj@ gc-mark-obj
global-env obj@ gc-mark-obj
depth gc-stack-depth @ do
\ ---- Loading files ---- {{{
-: charlist>cstr ( charlist addr -- n )
-
- dup 2swap ( origaddr addr charlist )
-
- begin
- nil? false =
- while
- 2dup cdr 2swap car
- drop ( origaddr addr charlist char )
- -rot 2swap ( origaddr charlist addr char )
- over !
- 1+ -rot ( origaddr nextaddr charlist )
- repeat
-
- 2drop ( origaddr finaladdr )
- swap -
-;
-
: load ( addr n -- finalResult )
open-input-file
2swap 2drop ( port obj )
+ expand
+
global-env obj@ eval ( port res )
again
;
true exit
then
+ expand
+
global-env obj@ eval
fg cyan ." ; " print reset-term
;
: repl
-
empty-parse-str
enable-gc
The Lambda Lab / projects / scheme.forth.jl.git / blobdiff