X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=scheme.4th;h=9a2a3ca1779e9fab029a6b6ef80893a09e621795;hb=ce188b101cbb79f55249d3eb6ff06e44ef065096;hp=72897bedbec770f312f62e273db0b0d9a45b600c;hpb=85e14c9d3e9509418125d2a7a6b7fa366a8f31ad;p=scheme.forth.jl.git diff --git a/scheme.4th b/scheme.4th index 72897be..9a2a3ca 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 ; @@ -103,6 +104,66 @@ variable nextfree objvar symbol-table +: duplicate-charlist ( charlist -- copy ) + 2dup nil objeq? false = if + 2dup car 2swap cdr recurse cons + then ; + +: charlist-equiv ( charlist charlist -- bool ) + + 2over 2over + + \ One or both nil + nil? -rot 2drop + if + nil? -rot 2drop + if + 2drop 2drop true exit + else + 2drop 2drop false exit + then + else + nil? -rot 2drop + if + 2drop 2drop false exit + then + then + + 2over 2over + + \ Neither nil + car drop -rot car drop = if + cdr 2swap cdr recurse + else + 2drop 2drop false + then +; + +: charlist>symbol ( charlist -- symbol-obj ) + + symbol-table obj@ + + begin + nil? false = + while + 2over 2over + car drop pair-type + charlist-equiv if + 2swap 2drop + car + exit + else + cdr + then + repeat + + 2drop + drop symbol-type 2dup + symbol-table obj@ cons + symbol-table obj! +; + + : (create-symbol) ( addr n -- symbol-obj ) dup 0= if 2drop nil @@ -124,9 +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+ @ @@ -137,6 +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 \ }}} @@ -175,19 +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 @@ -201,7 +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 @@ -236,15 +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 @@ -254,7 +317,7 @@ hide env objvar global-env nil nil nil extend-env -global-env setobj +global-env obj! \ }}} @@ -269,12 +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 @@ -599,60 +662,6 @@ parse-idx-stack parse-idx-sp ! cons ; -: charlist-equiv ( charlist charlist -- bool ) - - 2over 2over - - \ One or both nil - nil? -rot 2drop - if - nil? -rot 2drop - if - 2drop 2drop true exit - else - 2drop 2drop false exit - then - else - nil? -rot 2drop - if - 2drop 2drop false exit - then - then - - 2over 2over - - \ Neither nil - car drop -rot car drop = if - cdr 2swap cdr recurse - else - 2drop 2drop false - then -; - -: charlist>symbol ( charlist -- symbol-obj ) - - symbol-table fetchobj - - begin - nil? false = - while - 2over 2over - car drop pair-type - charlist-equiv if - 2swap 2drop - car - exit - else - cdr - then - repeat - - 2drop - drop symbol-type 2dup - symbol-table fetchobj cons - symbol-table setobj -; - : readpair ( -- pairobj ) eatspaces @@ -756,6 +765,7 @@ parse-idx-stack parse-idx-sp ! then eof? if + inc-parse-idx bold fg blue ." Moriturus te saluto." reset-term ." ok" cr quit then @@ -763,6 +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 \ }}} @@ -872,6 +888,21 @@ 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? ; @@ -902,6 +933,21 @@ defer eval then ; +: apply ( proc args ) + 2swap dup case + primitive-proc-type of + drop execute + endof + + compound-proc-type of + ." Compound procedures not yet implemented." + endof + + bold fg red ." Object not applicable. Aboring." reset-term cr + abort + endcase +; + :noname ( obj env -- result ) 2swap @@ -945,19 +991,20 @@ defer eval 2swap ['] eval goto then + lambda? if + 2dup lambda-body + 2swap lambda-parameters + 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 @@ -1032,6 +1079,9 @@ defer print : printprim ( primobj -- ) 2drop ." " ; +: printcomp ( primobj -- ) + 2drop ." " ; + :noname ( obj -- ) fixnum-type istype? if printnum exit then boolean-type istype? if printbool exit then @@ -1040,7 +1090,8 @@ 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 @@ -1059,7 +1110,7 @@ defer print begin cr bold fg green ." > " reset-term read - global-env fetchobj eval + global-env obj@ eval fg cyan ." ; " print reset-term again ;