include term-colours.4th
include defer-is.4th
+include goto.4th
include catch-throw.4th
include integer.4th
include float.4th
include debugging.4th
defer read
+defer expand
+defer analyze
defer eval
defer print
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 ,
+;
- [compile] if
- ['] -rot ,
- ['] display-exception-msg ,
- [compile] then
+make-exception recoverable-exception
+make-exception unrecoverable-exception
- ['] throw ,
-;
+: throw reset-term throw ;
\ }}}
then
nextfree @ scheme-memsize >= if
- unrecoverable-exception throw s" Out of memory!"
+ except-message: ." Out of memory!" unrecoverable-exception throw
then
;
R> R>
;
+: 2pick ( an bn an-1 bn-1 ... a0 b0 n -- an bn an-1 bn-1 ... a0 b0 an bn )
+ 2* 1+ dup
+ >R pick R> pick ;
+
\ }}}
\ ---- Pre-defined symbols ---- {{{
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
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
;
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
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 )
+\ ---- Analyze ----
- -2rot ( proc env exp )
- operands 2swap ( proc operands env )
- list-of-vals ( proc argvals )
+: evaluate-eproc ( eproc env --- res )
- apply
- exit
- then
+ >R >R
+
+ begin
+ nil? invert
+ while
+ 2dup car
+ 2swap cdr
+ repeat
+
+ 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 ( exp env -- exp )
+ 2drop ;
+
+: analyze-self-evaluating ( exp --- eproc )
+ ['] self-evaluating-executor primitive-proc-type
+ nil cons cons
+;
+
+: quote-executor ( exp env -- exp )
+ 2drop ;
+
+: analyze-quoted ( exp -- eproc )
+ quote-body
+
+ ['] quote-executor primitive-proc-type
+ nil cons cons
+;
+
+: variable-executor ( var env -- val )
+ lookup-var ;
+
+: analyze-variable ( exp -- eproc )
+ ['] variable-executor primitive-proc-type
+ nil cons cons
+;
+
+: definition-executor ( var val-eproc env -- ok )
+ 2swap 2over ( var env val-eproc env )
+ evaluate-eproc 2swap ( var val env )
+ define-var
+ ok-symbol
+;
+
+: analyze-definition ( exp -- eproc )
+ 2dup definition-var
+ 2swap definition-val analyze
+
+ ['] definition-executor primitive-proc-type
+ nil cons cons cons
+;
+
+: assignment-executor ( var val-eproc env -- ok )
+ 2swap 2over ( var env val-eproc env )
+ evaluate-eproc 2swap ( var val env )
+ set-var
+ ok-symbol
+;
+
+: analyze-assignment ( exp -- eproc )
+ 2dup assignment-var
+ 2swap assignment-val analyze ( var val-eproc )
+
+ ['] assignment-executor primitive-proc-type
+ 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
- recoverable-exception throw" Tried to evaluate object with unknown type."
-; is eval
+ 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
+
+ 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? 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
+ analyze-self-evaluating
+ exit
+ then
+
+ quote? if
+ analyze-quoted
+ exit
+ then
+
+ variable? if
+ analyze-variable
+ exit
+ then
+
+ definition? if
+ analyze-definition
+ exit
+ then
+
+ assignment? if
+ analyze-assignment
+ exit
+ then
+
+ if? if
+ analyze-if
+ exit
+ then
+
+ lambda? if
+ analyze-lambda
+ exit
+ then
+
+; is analyze
+
+
+\ ---- Macro Expansion ---- {{{
+
+( 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
+
+ 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
+
+ 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
\ }}}
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
\ }}}
;
:noname
- ." GC! "
+ \ ." GC! "
gc-unmark
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