X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fscheme.4th;h=6e2c49255a788a7293646ee0c5a751aab51dd7f9;hb=5eea24f47ad60b69af59a76c7285ec232c29009c;hp=77103885d041bf90ddb2ae027365e95065d2b248;hpb=bc2450b4b29d6bb8ba5422fb9eb7a75d1b6b5a57;p=scheme.forth.jl.git

diff --git a/src/scheme.4th b/src/scheme.4th
index 7710388..6e2c492 100644
--- a/src/scheme.4th
+++ b/src/scheme.4th
@@ -51,33 +51,21 @@ variable nextexception
     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 ,
+make-exception recoverable-exception
+make-exception unrecoverable-exception
 
-    [compile] if
-        ['] -rot ,
-        ['] display-exception-msg ,
-    [compile] then
-
-    ['] throw ,
-;
+: throw reset-term throw ;
 
 \ }}}
 
 \ ---- List-structured memory ---- {{{
 
-10000 constant scheme-memsize
+20000 constant scheme-memsize
 
 create car-cells scheme-memsize allot
 create car-type-cells scheme-memsize allot
@@ -103,7 +91,7 @@ variable nextfree
     then
 
     nextfree @ scheme-memsize >= if
-        unrecoverable-exception throw s" Out of memory!"
+        except-message: ." Out of memory!" unrecoverable-exception throw
     then
 ;
 
@@ -175,37 +163,6 @@ variable nextfree
 
 \ }}}
 
-\ ---- Port I/O ----  {{{
-
-: fileport>fid ( fileport -- fid )
-    drop ;
-
-: fid>fileport ( fid -- fileport )
-    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 port-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
@@ -305,12 +262,128 @@ 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 ;
+
+\ }}}
+
 \ ---- Environments ---- {{{
 
 : enclosing-env ( env -- env )
@@ -386,24 +459,30 @@ objvar vals
 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 -- )
@@ -451,11 +530,11 @@ global-env obj!
 : 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
@@ -465,17 +544,17 @@ global-env obj!
 : 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
@@ -545,7 +624,7 @@ global-env obj!
 
 : 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
 ;
 
@@ -559,6 +638,12 @@ objvar macro-table
 ( Look up macro in macro table. Returns nil if
   no macro is found. )
 : lookup-macro ( name_symbol -- proc )
+
+    symbol-type istype? invert if
+        \ Early exit if argument is not a symbol
+        2drop nil exit
+    then
+    
     macro-table obj@
 
     begin
@@ -648,7 +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
@@ -1236,12 +1321,12 @@ parse-idx-stack parse-idx-sp !
     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
@@ -1299,12 +1384,12 @@ defer eval-quasiquote-item
     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 )
@@ -1515,7 +1600,7 @@ hide env
 : 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
@@ -1532,7 +1617,7 @@ hide env
 
     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
@@ -1567,7 +1652,7 @@ hide env
                 R> drop ['] eval goto-deferred  \ Tail call optimization
             endof
 
-            recoverable-exception throw" Object not applicable."
+            except-message: ." object not applicable." recoverable-exception throw
         endcase
 ;
 
@@ -1588,6 +1673,13 @@ hide env
 :noname ( obj env -- result )
     2swap
 
+    \ --- DEBUG ---
+    ( 
+      fg yellow ." Evaluating: " bold 2dup print reset-term
+      space fg green ." PS: " bold depth . reset-term
+      space fg blue  ." RS: " bold RSP@ RSP0 - . reset-term cr
+    )
+
     self-evaluating? if
         2swap 2drop
         exit
@@ -1683,7 +1775,7 @@ hide env
         then
     then
 
-    recoverable-exception throw" Tried to evaluate object with unknown type."
+    except-message: ." tried to evaluate object with unknown type." recoverable-exception throw
 ; is eval
 
 \ }}}
@@ -1782,7 +1874,7 @@ hide env
     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
 
 \ }}}
@@ -1809,6 +1901,7 @@ variable gc-stack-depth
     string-type istype? if true exit then
     symbol-type istype? if true exit then
     compound-proc-type istype? if true exit then
+    port-type istype? if true exit then
 
     false
 ;
@@ -1875,6 +1968,7 @@ 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
@@ -1946,7 +2040,6 @@ variable gc-stack-depth
 ;
 
 : repl
-
     empty-parse-str
 
     enable-gc