X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=cecacff4bda20ae7fd4940f9762541179937b1d6;hb=9094335682c3a223c21f550dc94d766827ddedee;hp=ae88b4b44d746e824a9cd0c4e6e29ae49e0a24d6;hpb=659d7bdec81c23987b40c130008633e18f7001e7;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index ae88b4b..cecacff 100644 --- a/scheme.4th +++ b/scheme.4th @@ -13,7 +13,8 @@ include defer-is.4th 4 constant nil-type 5 constant pair-type 6 constant symbol-type -7 constant primitive-type +7 constant primitive-proc-type +8 constant compound-proc-type : istype? ( obj type -- obj bool ) over = ; @@ -77,8 +78,8 @@ variable nextfree : type@ ( objvar -- type ) 1+ @ ; : value! ( newval objvar -- ) ! ; : type! ( newtype objvar -- ) 1+ ! ; -: setobj ( newobj objvar -- ) dup rot swap 1+ ! ! ; -: fetchobj ( objvar -- obj ) dup @ swap 1+ @ ; +: obj! ( newobj objvar -- ) dup rot swap 1+ ! ! ; +: obj@ ( objvar -- obj ) dup @ swap 1+ @ ; : objeq? ( obj obj -- bool ) rot = -rot = and ; @@ -140,7 +141,7 @@ objvar symbol-table : charlist>symbol ( charlist -- symbol-obj ) - symbol-table fetchobj + symbol-table obj@ begin nil? false = @@ -158,8 +159,8 @@ objvar symbol-table 2drop drop symbol-type 2dup - symbol-table fetchobj cons - symbol-table setobj + symbol-table obj@ cons + symbol-table obj! ; @@ -184,9 +185,9 @@ objvar symbol-table 2dup - symbol-table fetchobj + symbol-table obj@ cons - symbol-table setobj + symbol-table obj! create swap , , does> dup @ swap 1+ @ @@ -197,6 +198,8 @@ create-symbol define define-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 \ }}} @@ -235,19 +238,19 @@ objvar vars objvar vals : get-vars-vals-frame ( var frame -- bool ) - 2dup frame-vars vars setobj - frame-vals vals setobj + 2dup frame-vars vars obj! + frame-vals vals obj! begin - vars fetchobj nil objeq? false = + vars obj@ nil objeq? false = while - 2dup vars fetchobj car objeq? if + 2dup vars obj@ car objeq? if 2drop true exit then - vars fetchobj cdr vars setobj - vals fetchobj cdr vals setobj + vars obj@ cdr vars obj! + vals obj@ cdr vals obj! repeat 2drop false @@ -261,7 +264,7 @@ objvar vals 2over 2over first-frame get-vars-vals-frame if 2drop 2drop - vars fetchobj vals fetchobj true + vars obj@ vals obj@ true exit then @@ -296,15 +299,15 @@ hide vals objvar env : define-var ( var val env -- ) - env setobj + env obj! - 2over env fetchobj ( var val var env ) + 2over env obj@ ( var val var env ) get-vars-vals if 2swap 2drop ( var val vals ) set-car! 2drop else - env fetchobj + env obj@ first-frame ( var val frame ) add-binding then @@ -314,7 +317,7 @@ hide env objvar global-env nil nil nil extend-env -global-env setobj +global-env obj! \ }}} @@ -329,12 +332,12 @@ global-env setobj 2dup - symbol-table fetchobj + symbol-table obj@ cons - symbol-table setobj + symbol-table obj! - rot primitive-type ( var prim ) - global-env fetchobj define-var + rot primitive-proc-type ( var prim ) + global-env obj@ define-var ; : arg-count-error @@ -770,6 +773,12 @@ parse-idx-stack parse-idx-sp ! \ Anything else is parsed as a symbol readsymbol charlist>symbol + \ Replace λ with lambda + 2dup λ-symbol objeq? if + 2drop lambda-symbol + then + + ; is read \ }}} @@ -808,11 +817,23 @@ defer eval : definition? ( obj -- obj bool ) define-symbol tagged-list? ; +: make-lambda ( params body -- lambda-exp ) + lambda-symbol -2rot cons cons ; + : definition-var ( obj -- var ) - cdr car ; + cdr car + symbol-type istype? false = if car then +; : definition-val ( obj -- val ) - cdr cdr car ; + 2dup cdr car symbol-type istype? if + 2drop + cdr cdr car + else + cdr 2swap cdr cdr + make-lambda + then +; : assignment? ( obj -- obj bool ) set!-symbol tagged-list? ; @@ -879,6 +900,21 @@ defer eval : true? ( boolobj -- bool ) false? invert ; +: lambda? ( obj -- obj bool ) + lambda-symbol tagged-list? ; + +: lambda-parameters ( obj -- params ) + cdr car ; + +: lambda-body ( obj -- body ) + cdr cdr ; + +: make-procedure ( params body env -- proc ) + nil + cons cons cons + drop compound-proc-type +; + : application? ( obj -- obj bool) pair-type istype? ; @@ -909,6 +945,50 @@ defer eval then ; +: procedure-params ( proc -- params ) + drop pair-type car ; + +: procedure-body ( proc -- body ) + drop pair-type cdr car ; + +: procedure-env ( proc -- body ) + drop pair-type cdr cdr car ; + +: apply ( proc args ) + 2swap dup case + primitive-proc-type of + drop execute + endof + + compound-proc-type of + 2dup procedure-body ( args proc body ) + -2rot 2dup procedure-params ( body args proc params ) + -2rot procedure-env ( body params args procenv ) + + extend-env ( body env ) + + 2swap ( env body ) + + begin + 2dup cdr 2dup nil objeq? false = + while + -2rot car over ( nextbody env exp env ) + eval + 2drop \ discard result + 2swap ( env nextbody ) + repeat + + 2drop ( env body ) + car 2swap ( exp env ) + + eval \ TODO: tail call optimization + endof + + bold fg red ." Object not applicable. Aboring." reset-term cr + abort + endcase +; + :noname ( obj env -- result ) 2swap @@ -952,19 +1032,20 @@ defer eval 2swap ['] eval goto then + lambda? if + 2dup lambda-parameters + 2swap lambda-body + 2rot make-procedure + exit + then + application? if 2over 2over operator 2swap eval - - primitive-type istype? false = if - bold fg red ." Object not applicable. Aboring." reset-term cr - abort - then - -2rot operands 2swap list-of-vals - 2swap drop execute + apply exit then @@ -1039,6 +1120,9 @@ defer print : printprim ( primobj -- ) 2drop ." " ; +: printcomp ( primobj -- ) + 2drop ." " ; + :noname ( obj -- ) fixnum-type istype? if printnum exit then boolean-type istype? if printbool exit then @@ -1047,7 +1131,8 @@ defer print symbol-type istype? if printsymbol exit then nil-type istype? if printnil exit then pair-type istype? if ." (" printpair ." )" exit then - primitive-type istype? if printprim exit then + primitive-proc-type istype? if printprim exit then + compound-proc-type istype? if printcomp exit then bold fg red ." Error printing expression - unrecognized type. Aborting" reset-term cr abort @@ -1066,7 +1151,7 @@ defer print begin cr bold fg green ." > " reset-term read - global-env fetchobj eval + global-env obj@ eval fg cyan ." ; " print reset-term again ;