From 614bb8225bbbfd518bc1444c9f3bd77a5addfcfe Mon Sep 17 00:00:00 2001
From: mtardy <mahe5397@hotmail.fr>
Date: Thu, 6 Aug 2020 08:52:15 +0200
Subject: [PATCH] Add return

---
 object.c  |  2 +-
 parse.leg | 32 +++++++++++++++++++++++++++++++-
 test2.txt | 10 +++++++---
 3 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/object.c b/object.c
index cfc4b41..cbe4e31 100644
--- a/object.c
+++ b/object.c
@@ -3,7 +3,7 @@
 #include <sysexits.h>
 #include <assert.h>
 
-#define USE_TAG  0
+#define USE_TAG  1
 
 #define USE_GC   1
 
diff --git a/parse.leg b/parse.leg
index ad53eae..f340ef0 100644
--- a/parse.leg
+++ b/parse.leg
@@ -12,7 +12,8 @@
     _DO(logor) _DO(logand) _DO(bitor) _DO(bitxor) _DO(bitand)                                           \
     _DO(equal) _DO(noteq) _DO(less) _DO(lesseq) _DO(greater) _DO(greatereq) _DO(shleft) _DO(shright)    \
     _DO(add) _DO(sub) _DO(mul) _DO(div) _DO(mod) _DO(not) _DO(neg) _DO(com)                             \
-    _DO(getMember) _DO(setMember) _DO(getIndex) _DO(setIndex)
+    _DO(getMember) _DO(setMember) _DO(getIndex) _DO(setIndex)                                           \
+    _DO(return)
 
 typedef enum {
 t_UNDEFINED=0,
@@ -259,6 +260,13 @@ oop newCompoundStatement(oop statements)
     return obj;
 }
 
+oop newReturn(oop exp)
+{
+    oop obj = newObject(return_proto);
+    map_set(obj, value_symbol, exp);
+    return obj;
+}
+
 // this always creates the key in "object"
 oop newVariable(oop object, oop key, oop value)
 {
@@ -309,6 +317,8 @@ exp     =   VAR l:IDENT                        ASSIGN e:exp  { $$ = newDeclarati
         |   IF        LPAREN c:exp RPAREN t:stmt ELSE f:stmt { $$ = newIf(c, t, f   ) }
         |   IF        LPAREN c:exp RPAREN t:stmt             { $$ = newIf(c, t, null) }
         |   WHILE LPAREN c:exp RPAREN e:stmt                 { $$ = newWhile(c, e) }
+        |   RETURN                                    e:exp  { $$ = newReturn(e) }
+        |   RETURN                                           { $$ = newReturn(null) }
         |       l:IDENT                        ASSIGN e:exp  { $$ = newAssign(l, e) }
         |       l:postfix DOT   i:IDENT        ASSIGN e:exp  { $$ = newSetMember(l, i, e) }
         |       l:postfix LBRAC i:exp   RBRAC  ASSIGN e:exp  { $$ = newSetIndex(l, i, e) }
@@ -441,6 +451,7 @@ WHILE   =    'while'    ![a-zA-Z0-9_]     -
 IF      =    'if'       ![a-zA-Z0-9_]     -
 ELSE    =    'else'     ![a-zA-Z0-9_]     -
 NULL    =    'null'     ![a-zA-Z0-9_]     -
+RETURN  =    'return'   ![a-zA-Z0-9_]     -
 HASH    =    '#'                -
 LOGOR   =    '||'               -
 LOGAND  =    '&&'               -
@@ -604,11 +615,30 @@ oop eval(oop scope, oop ast)
         oop localScope = newObject(scope);
         while ((index = makeInteger(i)), map_hasKey(statements, index)) {
             statement = map_get(statements, index);
+
+            // RETURN STUFF
+            oop proto = map_get(statement, __proto___symbol);
+            proto_t proto_number = 0;
+            if (proto != null) {
+                proto_number = get(map_get(proto, __name___symbol), Symbol, prototype);
+            }
+            // we are doing the work twice because the eval cannot return a special case to signal that it's a return statement
+
             res = eval(localScope, statement);
+
+            // RETURN STUFF
+            if (proto_number == t_return) {
+                break;
+            }
+
             i++;
         }
         return res;
     }
+    case t_return: {
+        oop exp = eval(scope, map_get(ast, value_symbol));
+        return exp;
+    }
     case t_getMember: {
         oop map = eval(scope, map_get(ast, map_symbol));
         oop key = map_get(ast, key_symbol);
diff --git a/test2.txt b/test2.txt
index 4beccaf..137aaab 100644
--- a/test2.txt
+++ b/test2.txt
@@ -1,6 +1,10 @@
-var a = 2
 fun f() {
-   var a = 10
+    if (1) {
+        return 12
+        15
+    } else {
+        return 13
+        14
+    }
 }
-a
 f()
\ No newline at end of file