X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fscheme.4th;h=9b5eb278adbd91e1f79e79e7d9d45b862d85e422;hb=a0ba878648ac5b9c3e4d013d7666b2b7d3d45f77;hp=3931dad19d68bd141f609ce8cb297a6634621cdd;hpb=02868ff84afc9b2fb4fafa7247d09ee2a1e98f59;p=scheme.forth.jl.git

diff --git a/src/scheme.4th b/src/scheme.4th
index 3931dad..9b5eb27 100644
--- a/src/scheme.4th
+++ b/src/scheme.4th
@@ -263,6 +263,7 @@ 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
 
 \ Symbol to be bound to welcome message procedure by library
 create-symbol welcome           welcome-symbol
@@ -1403,34 +1404,21 @@ defer eval-quasiquote-item
 : definition? ( obj -- obj bool )
     define-symbol tagged-list? ;
 
-: make-lambda ( params body -- lambda-exp )
-    lambda-symbol -2rot cons cons ;
-
-( Handles iterative expansion of defines in
-  terms of nested lambdas. Most Schemes only
-  handle one iteration of expansion! )
-: definition-var-val ( obj -- var val )
-
-    cdr 2dup cdr 2swap car ( val var )
-
-    begin
-        symbol-type istype? false =
-    while
-        2dup cdr 2swap car ( val formals var' )
-        -2rot 2swap ( var' formals val )
-        make-lambda nil cons ( var' val' )
-        2swap ( val' var' )
-    repeat
+: definition-var ( obj -- var )
+    cdr car ;
 
-    2swap car
-;
+: definition-val ( obj -- val )
+    cdr cdr car ;
 
 : eval-definition ( obj env -- res )
-    2dup 2rot ( env env obj )
-    definition-var-val ( env env var val )
-    2rot eval  ( env var val )
+    2swap
+    2over 2over
+    definition-val 2swap
+    eval
 
-    2rot ( var val env )
+    2swap definition-var 2swap
+
+    2rot
     define-var
 
     ok-symbol
@@ -1766,17 +1754,124 @@ hide env
     extend-env eval-sequence eval
 ;
 
-: expand-quasiquote ;
-: expand-definition ;
-: expand-assignment ;
-: expand-define-macro ;
-: expand-if ;
-: expand-lambda ;
-: expand-begin ;
-: expand-application ;
+defer expand
+
+: expand-macro ( exp -- result )
+    pair-type istype? invert if exit then
+    2dup car symbol-type istype? invert if 2drop exit then
+    
+    lookup-macro nil? if
+        2drop exit then
+
+    2over cdr macro-eval
+
+    2dup no-match-symbol objeq? if
+        2drop exit
+    else
+        2swap 2drop
+    then
+
+    R> drop ['] expand goto-deferred
+;
+
+: expand-quasiquote-item ( exp -- result )
+    nil? if exit then
+
+    unquote? if
+        unquote-symbol 2swap cdr expand nil cons cons
+        exit
+    then
+    
+    pair? 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
+
+    2dup definition-var
+    2swap definition-val expand
+    nil ( define var val' nil )
+
+    cons cons cons ;
+
+: expand-assignment ( exp -- result )
+    set!-symbol 2swap
+
+    2dup assignment-var
+    2swap assignment-val expand
+    nil ( define var val' nil )
+
+    cons cons cons ;
+
+: expand-list ( exp -- res )
+    nil? if exit then
+
+    2dup car expand
+    2swap cdr recurse
+
+    cons ;
+
+: macro-definition-nameparams
+    cdr car ;
+
+: 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-list
+
+    cons cons ;
+
+: expand-if ( exp -- res )
+    if-symbol 2swap
+    
+    2dup if-predicate expand
+    2swap 2dup if-consequent expand
+    2swap if-alternative none? if
+        2drop nil
+    else
+        nil cons
+    then
+
+    cons cons cons ;
+
+: expand-begin ( exp -- res )
+    begin-symbol 2swap
+    begin-actions expand-list
+
+    cons ;
+
+: expand-application ( exp -- res )
+    2dup operator
+    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
 
     definition? if expand-definition exit then
@@ -1785,13 +1880,13 @@ hide env
 
     macro-definition? if expand-define-macro exit then
 
-    if? if expand-if exit then
-
     lambda? if expand-lambda exit then
 
-    begin? if expand-sequence exit then
+    if? if expand-if exit then
+
+    begin? if expand-begin exit then
 
-    application? if expand-apply exit then
+    application? if expand-application exit then
 
 ; is expand
 
@@ -2033,6 +2128,8 @@ variable gc-stack-depth
 
     include scheme-primitives.4th
 
+    s" scheme-derived-forms.scm" load 2drop
+
 \    s" scheme-library.scm" load 2drop
     
 \ }}}