X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fscheme.4th;h=5ee0dbd16a6549f8f1c588b272951ea0425a2671;hb=2899e37fdb0ecf89bb949cfcc0a9db2cac54677f;hp=5babf09388d23517af2374852eb899fcfecdfb78;hpb=18d5eef9c97da9c27bf9bb5cdaba6baf4a85f966;p=scheme.forth.jl.git

diff --git a/src/scheme.4th b/src/scheme.4th
index 5babf09..5ee0dbd 100644
--- a/src/scheme.4th
+++ b/src/scheme.4th
@@ -4,6 +4,7 @@ scheme definitions
 include term-colours.4th
 include defer-is.4th
 include catch-throw.4th
+include integer.4th
 include float.4th
 
 include debugging.4th
@@ -25,6 +26,7 @@ variable nexttype
 
 make-type fixnum-type
 make-type flonum-type
+make-type ratnum-type
 make-type boolean-type
 make-type character-type
 make-type string-type
@@ -34,7 +36,7 @@ make-type pair-type
 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 = ;
 
@@ -173,37 +175,6 @@ variable nextfree
 
 \ }}}
 
-\ ---- 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
@@ -303,6 +274,125 @@ 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
+
+\ 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 ;
 
 \ }}}
 
@@ -643,7 +733,7 @@ parse-idx-stack parse-idx-sp !
         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
@@ -786,6 +876,42 @@ parse-idx-stack parse-idx-sp !
     pop-parse-idx
 ;
 
+: ratnum? ( -- bool )
+    push-parse-idx
+
+    minus? plus? or if
+        inc-parse-idx
+    then
+
+    digit? invert if
+        pop-parse-idx false exit
+    else
+        inc-parse-idx
+    then
+
+    begin digit? while
+        inc-parse-idx
+    repeat
+
+    [char] / nextchar <> if
+        pop-parse-idx false exit
+    else
+        inc-parse-idx
+    then
+
+    digit? invert if
+        pop-parse-idx false exit
+    else
+        inc-parse-idx
+    then
+
+    begin digit? while
+        inc-parse-idx
+    repeat
+
+    delim? pop-parse-idx
+;
+
 : boolean? ( -- bool )
     nextchar [char] # <> if false exit then
 
@@ -906,6 +1032,23 @@ parse-idx-stack parse-idx-sp !
     flonum-type
 ;
 
+: make-rational ( fixnum fixnum -- ratnum|fixnum )
+    drop swap drop
+    simplify
+
+    dup 1 = if
+        drop fixnum-type
+    else
+        fixnum-type swap fixnum-type
+        cons drop ratnum-type
+    then
+;
+
+: readratnum ( -- ratnum )
+    readfixnum inc-parse-idx readfixnum
+    make-rational
+;
+
 : readbool ( -- bool-obj )
     inc-parse-idx
     
@@ -934,35 +1077,51 @@ parse-idx-stack parse-idx-sp !
 ;
 
 : readstring ( -- charlist )
-    nextchar [char] " = if
-        inc-parse-idx
 
-        delim? false = if
-            bold fg red
-            ." No delimiter following right double quote. Aborting." cr
-            reset-term abort
+    nil nil
+
+    begin
+        nextchar [char] " <>
+    while
+        nextchar [char] \ = if
+            inc-parse-idx
+            nextchar case
+                [char] n of '\n' endof
+                [char] " of [char] " endof
+                [char] \
+            endcase
+        else
+            nextchar
         then
+        inc-parse-idx character-type
+        nil cons
 
-        dec-parse-idx
+        ( firstchar prevchar thischar )
 
-        0 nil-type exit
-    then
+        2swap nil? if
+            2drop 2swap 2drop 2dup  ( thischar thischar )
+        else
+            ( firstchar thischar prevchar )
+            2over 2swap  set-cdr! ( firstchar thischar )
+        then
+    repeat
 
-    nextchar [char] \ = if
-        inc-parse-idx
-        nextchar case
-            [char] n of '\n' endof
-            [char] " of [char] " endof
-            [char] \
-        endcase
-    else
-        nextchar
+    \ Discard previous character
+    2drop
+
+    inc-parse-idx
+    delim? false = if
+        bold fg red
+        ." No delimiter following right double quote. Aborting." cr
+        reset-term abort
     then
-    inc-parse-idx character-type
 
-    recurse
+    dec-parse-idx
 
-    cons
+    nil? if
+        nil cons
+    then
+    drop string-type
 ;
 
 : readsymbol ( -- charlist )
@@ -1032,6 +1191,11 @@ parse-idx-stack parse-idx-sp !
         exit
     then
 
+    ratnum? if
+        readratnum
+        exit
+    then
+
     boolean? if
         readbool
         exit
@@ -1046,7 +1210,6 @@ parse-idx-stack parse-idx-sp !
         inc-parse-idx
 
         readstring
-        drop string-type
 
         nextchar [char] " <> if
             bold red ." Missing closing double-quote." reset-term cr
@@ -1122,6 +1285,7 @@ parse-idx-stack parse-idx-sp !
     boolean-type istype? if true exit then
     fixnum-type istype? if true exit then
     flonum-type istype? if true exit then
+    ratnum-type istype? if true exit then
     character-type istype? if true exit then
     string-type istype? if true exit then
     nil-type istype? if true exit then
@@ -1615,6 +1779,11 @@ hide env
 
 : printflonum ( flonum -- ) drop f. ;
 
+: printratnum ( ratnum -- )
+    drop pair-type 2dup
+    car print ." /" cdr print
+;
+
 : printbool ( bool -- )
     drop if
         ." #t"
@@ -1686,6 +1855,7 @@ hide env
 :noname ( obj -- )
     fixnum-type istype? if printfixnum exit then
     flonum-type istype? if printflonum exit then
+    ratnum-type istype? if printratnum exit then
     boolean-type istype? if printbool exit then
     character-type istype? if printchar exit then
     string-type istype? if printstring exit then
@@ -1695,6 +1865,7 @@ hide env
     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."
 ; is print
@@ -1789,6 +1960,7 @@ variable gc-stack-depth
 
     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
@@ -1807,24 +1979,6 @@ variable gc-stack-depth
 
 \ ---- 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
 
@@ -1878,13 +2032,14 @@ variable gc-stack-depth
 ;
 
 : repl
-    cr ." Welcome to scheme.forth.jl!" cr
-       ." Use Ctrl-D to exit." cr
 
     empty-parse-str
 
     enable-gc
 
+    \ Display welcome message
+    welcome-symbol nil cons global-env obj@ eval 2drop
+
     begin
         ['] repl-body catch
         case