X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=scheme.forth.jl.git;a=blobdiff_plain;f=src%2Fscheme.4th;h=ec97f09761c26f8603c14001277cd08b6f5e7dd8;hp=0722208250945ab9165d8d6b1c410711ee65cdc8;hb=724ff46a1b082bef48b310a85d5a82037c2a914c;hpb=f1bd626bdb02170b189891d8f8f3f3cc6b592209

diff --git a/src/scheme.4th b/src/scheme.4th
index 0722208..ec97f09 100644
--- a/src/scheme.4th
+++ b/src/scheme.4th
@@ -10,6 +10,7 @@ include float.4th
 include debugging.4th
 
 defer read
+defer expand
 defer eval
 defer print
 
@@ -261,7 +262,6 @@ 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 eof               eof-symbol
 create-symbol no-match          no-match-symbol
 
@@ -1512,12 +1512,6 @@ hide env
 : lambda-body ( obj -- body )
     cdr cdr ;
 
-: begin? ( obj -- obj bool )
-    begin-symbol tagged-list? ;
-
-: begin-actions ( obj -- actions )
-    cdr ;
-
 : eval-sequence ( explist env -- finalexp env )
     ( Evaluates all bar the final expressions in
       an an expression list. The final expression
@@ -1712,12 +1706,6 @@ hide env
         exit
     then
 
-    begin? if
-        begin-actions 2swap
-        eval-sequence
-        ['] eval goto-deferred
-    then
-
     application? if
 
         2over 2over ( env exp env exp )
@@ -1754,14 +1742,6 @@ hide env
     extend-env eval-sequence eval
 ;
 
-defer expand
-
-: expand-quasiquote ;
-: expand-define-macro ;
-: expand-if ;
-: expand-lambda ;
-: expand-application ;
-
 : expand-macro ( exp -- result )
     pair-type istype? invert if exit then
     2dup car symbol-type istype? invert if 2drop exit then
@@ -1780,6 +1760,33 @@ defer expand
     R> drop ['] expand goto-deferred
 ;
 
+: expand-quasiquote-item ( exp -- result )
+    nil? if exit then
+
+    unquote? if
+        unquote-symbol 2swap cdr car expand nil cons cons
+        exit
+    then
+
+    unquote-splicing? if
+        unquote-splicing-symbol 2swap cdr car expand nil cons cons
+        exit
+    then
+    
+    pair-type istype? if
+        2dup car recurse
+        2swap cdr recurse
+        cons
+    then
+;
+
+: expand-quasiquote ( exp -- result )
+    quasiquote-symbol 2swap cdr
+
+    expand-quasiquote-item
+
+    cons ;
+
 : expand-definition ( exp -- result )
     define-symbol 2swap
 
@@ -1798,7 +1805,7 @@ defer expand
 
     cons cons cons ;
 
-: expand-sequence ( exp -- res )
+: expand-list ( exp -- res )
     nil? if exit then
 
     2dup car expand
@@ -1806,23 +1813,47 @@ defer expand
 
     cons ;
 
-: expand-begin ( exp -- res )
-    begin-symbol 2swap
-    begin-actions expand-sequence
+: macro-definition-nameparams
+    cdr car ;
 
-    cons ;
+: expand-define-macro ( exp -- res )
+    define-macro-symbol 2swap
+    2dup macro-definition-nameparams
+    2swap macro-definition-body expand-list
+
+    cons cons ;
 
 : expand-lambda ( exp -- res )
     lambda-symbol 2swap
     2dup lambda-parameters
-    2swap lambda-body expand-sequence
+    2swap lambda-body expand-list
 
     cons cons ;
 
-:noname ( exp -- result )
+: expand-if ( exp -- res )
+    if-symbol 2swap
+    
+    2dup if-predicate expand
+    2swap 2dup if-consequent expand
+    2swap if-alternative none? if
+        2drop nil
+    else
+        expand nil cons
+    then
+
+    cons cons cons ;
+
+: expand-application ( exp -- res )
+    2dup operator expand
+    2swap operands expand-list
+
+    cons ;
 
+:noname ( exp -- result )
     expand-macro
 
+    self-evaluating? if exit then
+
     quote? if exit then
 
     quasiquote? if expand-quasiquote exit then
@@ -1833,11 +1864,9 @@ defer expand
 
     macro-definition? if expand-define-macro exit then
 
-    if? if expand-if exit then
-
     lambda? if expand-lambda exit then
 
-    begin? if expand-begin exit then
+    if? if expand-if exit then
 
     application? if expand-application exit then
 
@@ -2081,9 +2110,7 @@ variable gc-stack-depth
 
     include scheme-primitives.4th
 
-    s" scheme-derived-forms.scm" load 2drop
-
-\    s" scheme-library.scm" load 2drop
+    s" scheme-library.scm" load 2drop
     
 \ }}}
 
@@ -2116,7 +2143,7 @@ variable gc-stack-depth
     enable-gc
 
     \ Display welcome message
-    \ welcome-symbol nil cons global-env obj@ eval 2drop
+    welcome-symbol nil cons global-env obj@ eval 2drop
 
     begin
         ['] repl-body catch