X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=fc307d718b150f12e547dbbd508eb9ae7eb5f6c9;hb=7ea88126cc603f83d9bfd54816bc47e88a12e7cf;hp=12c07d2a72cbaa02dfe6f04cf54e0ef229e80420;hpb=8db1ca2b987bbea36b7f1f9a1ab1baafb49fef9e;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index 12c07d2..fc307d7 100644 --- a/scheme.4th +++ b/scheme.4th @@ -180,7 +180,7 @@ console-i/o-port obj@ current-input-port obj! objvar symbol-table : duplicate-charlist ( charlist -- copy ) - 2dup nil objeq? false = if + nil? false = if 2dup car 2swap cdr recurse cons then ; @@ -239,7 +239,7 @@ objvar symbol-table ; -: cstr>charlist ( addr n -- symbol-obj ) +: cstr>charlist ( addr n -- charlist ) dup 0= if 2drop nil else @@ -256,27 +256,24 @@ objvar symbol-table count cstr>charlist - drop symbol-type - - 2dup - - symbol-table obj@ - cons - symbol-table obj! + charlist>symbol create swap , , does> dup @ swap 1+ @ ; -create-symbol quote quote-symbol -create-symbol define define-symbol -create-symbol define-macro define-macro-symbol -create-symbol set! set!-symbol -create-symbol ok ok-symbol -create-symbol if if-symbol -create-symbol lambda lambda-symbol -create-symbol λ λ-symbol -create-symbol begin begin-symbol +create-symbol quote quote-symbol +create-symbol quasiquote quasiquote-symbol +create-symbol unquote unquote-symbol +create-symbol unquote-splicing unquote-splicing-symbol +create-symbol define define-symbol +create-symbol define-macro define-macro-symbol +create-symbol set! set!-symbol +create-symbol ok ok-symbol +create-symbol if if-symbol +create-symbol lambda lambda-symbol +create-symbol λ λ-symbol +create-symbol begin begin-symbol \ }}} @@ -336,7 +333,7 @@ objvar vals : get-vars-vals ( var env -- vars? vals? bool ) begin - 2dup nil objeq? false = + nil? false = while 2over 2over first-frame get-vars-vals-frame if @@ -402,6 +399,54 @@ objvar global-env nil nil nil extend-env global-env obj! +\ }}} + +\ ---- Primitives ---- {{{ + +: make-primitive ( cfa -- ) + bl word + count + + \ 2dup ." Defining primitive " type ." ..." cr + + cstr>charlist + charlist>symbol + + rot primitive-proc-type ( var prim ) + global-env obj@ define-var +; + +: arg-count-error + bold fg red ." Incorrect argument count." reset-term cr + abort +; + +: ensure-arg-count ( args n -- ) + dup 0= if + drop nil objeq? false = if + arg-count-error + then + else + -rot nil? if + arg-count-error + then + + cdr rot 1- recurse + then +; + +: arg-type-error + bold fg red ." Incorrect argument type." reset-term cr + abort +; + +: ensure-arg-type ( arg type -- arg ) + istype? false = if + arg-type-error + then +; + + \ }}} \ ---- Macros ---- {{{ @@ -422,7 +467,11 @@ objvar macro-table car cdr exit then + + cdr repeat + + 2swap 2drop ; : make-macro ( name_symbol params body env -- ) @@ -442,6 +491,8 @@ objvar macro-table set-cdr! exit then + + cdr repeat 2drop @@ -918,6 +969,21 @@ parse-idx-stack parse-idx-sp ! quote-symbol recurse nil cons cons exit then + nextchar [char] ` = if + inc-parse-idx + quasiquote-symbol recurse nil cons cons exit + then + + nextchar [char] , = if + inc-parse-idx + nextchar [char] @ = if + inc-parse-idx + unquote-splicing-symbol recurse nil cons cons exit + else + unquote-symbol recurse nil cons cons exit + then + then + eof? if EOF character-type inc-parse-idx @@ -974,19 +1040,34 @@ parse-idx-stack parse-idx-sp ! : make-lambda ( params body -- lambda-exp ) lambda-symbol -2rot cons cons ; -: definition-var ( obj -- var ) - cdr car - symbol-type istype? false = if car then +( 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 + + 2swap car ; -: definition-val ( obj -- val ) - 2dup cdr car symbol-type istype? if - 2drop - cdr cdr car - else - cdr 2swap cdr cdr - make-lambda - then +: eval-definition ( obj env -- res ) + 2dup 2rot ( env env obj ) + definition-var-val ( env env var val ) + 2rot eval ( env var val ) + + 2rot ( var val env ) + define-var + + ok-symbol ; : assignment? ( obj -- obj bool ) @@ -998,20 +1079,6 @@ parse-idx-stack parse-idx-sp ! : assignment-val ( obj -- val ) cdr cdr car ; -: eval-definition ( obj env -- res ) - 2swap - 2over 2over ( env obj env obj ) - definition-val 2swap ( env obj valexp env ) - eval ( env obj val ) - - 2swap definition-var 2swap ( env var val ) - - 2rot ( var val env ) - define-var - - ok-symbol -; - : eval-assignment ( obj env -- res ) 2swap 2over 2over ( env obj env obj ) @@ -1065,7 +1132,7 @@ hide env : if-alternative ( ifobj -- alt|false ) cdr cdr cdr - 2dup nil objeq? if + nil? if 2drop false else car @@ -1105,14 +1172,14 @@ hide env 2swap ( env explist ) \ Abort on empty list - 2dup nil objeq? if + nil? if 2drop none 2swap exit then begin 2dup cdr ( env explist nextexplist ) - 2dup nil objeq? false = + nil? false = while -2rot car 2over ( nextexplist env exp env ) eval @@ -1165,7 +1232,15 @@ hide env ( Ensure terminating symbol arg name is handled specially to allow for variadic procedures. ) : flatten-proc-args ( argvals argnames -- argvals' argnames' ) - nil? if exit then + nil? if + 2over nil? false = if + bold fg red ." Too many arguments supplied to compound method. Aborting." reset-term cr + abort + else + 2drop + then + exit + then symbol-type istype? if nil cons @@ -1175,17 +1250,26 @@ hide env exit then - 2over cdr 2over cdr + 2over + nil? if + bold fg red ." Too few arguments supplied to compound method. Aborting." reset-term cr + abort + else + cdr + then + + 2over cdr + recurse ( argvals argnames argvals'' argnames'' ) 2rot car 2swap cons ( argvals argvals'' argnames' ) 2rot car 2rot cons ( argnames' argvals' ) 2swap ; -: apply ( proc argvals ) +: apply ( proc argvals -- result ) 2swap dup case primitive-proc-type of - drop execute + drop execute endof compound-proc-type of @@ -1204,11 +1288,24 @@ hide env R> drop ['] eval goto-deferred \ Tail call optimization endof - bold fg red ." Object not applicable. Aboring." reset-term cr + bold fg red ." Object not applicable. Aborting." reset-term cr abort endcase ; +: 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 @@ -1274,29 +1371,32 @@ hide env application? if 2over 2over ( env exp env exp ) - operator 2dup ( env exp env opname opname ) + operator ( env exp env opname ) + + 2dup lookup-macro nil? false = if + \ Macro function evaluation + + ( env exp env opname mproc ) + 2swap 2drop -2rot 2drop cdr ( env mproc body ) + + macro-expand - lookup-macro 2dup nil objeq? if - \ Regular function application + 2swap + ['] eval goto-deferred + else + \ Regular function application 2drop ( env exp env opname ) 2swap eval ( env exp proc ) + -2rot ( proc env exp ) operands 2swap ( proc operands env ) list-of-vals ( proc argvals ) apply - else - \ Macro function evaluation - - ( env exp env opname mproc ) - 2swap 2drop -2rot 2drop ( env mproc exp ) - apply 2swap ( expanded-exp env ) - - ['] eval goto-deferred + exit then - exit then bold fg red ." Error evaluating expression - unrecognized type. Aborting." reset-term cr @@ -1499,61 +1599,6 @@ variable gc-stack-depth \ }}} -\ ---- Primitives ---- {{{ - -: make-primitive ( cfa -- ) - bl word - count - - \ 2dup ." Defining primitive " type ." ..." cr - - cstr>charlist - drop symbol-type - - 2dup - - symbol-table obj@ - cons - symbol-table obj! - - rot primitive-proc-type ( var prim ) - global-env obj@ define-var -; - -: arg-count-error - bold fg red ." Incorrect argument count." reset-term cr - abort -; - -: ensure-arg-count ( args n -- ) - dup 0= if - drop nil objeq? false = if - arg-count-error - then - else - -rot 2dup nil objeq? if - arg-count-error - then - - cdr rot 1- recurse - then -; - -: arg-type-error - bold fg red ." Incorrect argument type." reset-term cr - abort -; - -: ensure-arg-type ( arg type -- arg ) - istype? false = if - arg-type-error - then -; - -include scheme-primitives.4th - -\ }}} - \ ---- Loading files ---- {{{ : charlist>cstr ( charlist addr -- n ) @@ -1561,7 +1606,7 @@ include scheme-primitives.4th dup 2swap ( origaddr addr charlist ) begin - 2dup nil objeq? false = + nil? false = while 2dup cdr 2swap car drop ( origaddr addr charlist char ) @@ -1595,15 +1640,14 @@ include scheme-primitives.4th again ; -:noname ( args -- finalResult ) - 2dup 1 ensure-arg-count - car string-type ensure-arg-type +\ }}} - drop pair-type - pad charlist>cstr - pad swap load -; make-primitive load +\ ---- Standard Library ---- {{{ + include scheme-primitives.4th + + s" scheme-library.scm" load 2drop + \ }}} \ ---- REPL ----