From 8957b242ad5231361454f7938e0afb3095bf23a7 Mon Sep 17 00:00:00 2001
From: mtardy <mahe5397@hotmail.fr>
Date: Thu, 23 Jul 2020 09:34:55 +0200
Subject: [PATCH] Fix symbol table

---
 calc.leg | 18 ++++++++----------
 object.c | 52 ++++++++++++++++++++++++----------------------------
 2 files changed, 32 insertions(+), 38 deletions(-)

diff --git a/calc.leg b/calc.leg
index b3d300a..1ed7631 100644
--- a/calc.leg
+++ b/calc.leg
@@ -9,9 +9,7 @@
 #include "object.c"
 
 // this is the global scope
-// oop globals;
-
-// this should stay out of object.c because it manipulates Symbol members defined in this file
+oop globals;
 
 oop apply(oop function, oop parameters)
 {
@@ -26,7 +24,7 @@ YYSTYPE yylval;
 
 start   = - e:exp               { yylval = e }
 
-exp     =   l:IDENT                             EQUAL p:exp	{ $$ = variableSet(l, p) }
+exp     =   l:IDENT                             EQUAL p:exp	{ $$ = map_set(globals, l, p) }
             |   l:postfix DOT   i:IDENT         EQUAL p:exp	{ $$ = map_set(l, i, p) }
             |   l:postfix LBRAC i:exp   RBRAC   EQUAL p:exp	{ $$ = map_set(l, i, p) }
             |   s:sum                                       { $$ = s }
@@ -46,7 +44,7 @@ prefix  =   MINUS n:prefix              { set(n, Integer, value, -get(n, Integer
         |   PLUS  n:prefix              { $$ = n }
         |         n:postfix             { $$ = n }
 
-postfix =   i:value ( DOT    s:IDENT        p:parameterList     { map_set(p, intern(globals, "this"), i);  i = apply(map_get(i, s), p) }
+postfix =   i:value ( DOT    s:IDENT        p:parameterList     { map_set(p, intern("this"), i);  i = apply(map_get(i, s), p) }
                     | DOT    s:IDENT        !EQUAL              { i = map_get(i, s) }
                     | LBRAC  p:exp   RBRAC  !EQUAL              { i = map_get(i, p) }
                     | p:parameterList                           { i = apply(i, p) }
@@ -64,14 +62,14 @@ value   =   n:NUMBER                { $$ = n }
         |   s:symbol                { $$ = s }
         |   m:map                   { $$ = m }
         |   NULL                    { $$ = null }
-        |   i:IDENT                 { $$ = variableGet(i) }
+        |   i:IDENT                 { $$ = map_get(globals, i) }
         |   LPAREN i:exp RPAREN     { $$ = i }
 
 string  =   SQUOTE < (!SQUOTE .)* > SQUOTE      { $$ = makeString(yytext) }
         |   DQUOTE < (!DQUOTE .)* > DQUOTE      { $$ = makeString(yytext) }
 
 symbol  =   HASH    ( i:IDENT                   { $$ = i }
-                    | i:string                  { $$ = intern(globals, get(i, String, value)) }
+                    | i:string                  { $$ = intern(get(i, String, value)) }
                     )
 
 map     =   LCB   m:makeMap
@@ -86,7 +84,7 @@ makeMap =   { $$ = makeMap() }
 -       =   [ \t\n\r]*
         | "//"  ( ![\n\r] . )*
 
-IDENT	=	< [a-zA-Z][a-zA-Z0-9_]* >   -   { $$ = intern(globals, yytext) }
+IDENT	=	< [a-zA-Z][a-zA-Z0-9_]* >   -   { $$ = intern(yytext) }
 NUMBER	=	< [0-9]+ >	-                   { $$ = makeInteger(atoi(yytext)) }
 HASH	=	'#'			-
 PLUS	=	'+'			-
@@ -120,10 +118,10 @@ oop prim_exit(oop params)
 
 int main(int argc, char **argv)
 {
+    symbol_table = makeMap();
     globals = makeMap();
 
-    variableSet(intern(globals, "exit"), makeFunction(prim_exit));
-    // map_set(globals, intern("exit"), makeFunction(prim_exit));
+    map_set(globals, intern("exit"), makeFunction(prim_exit));
 
     while (yyparse()) {
         println(yylval);
diff --git a/object.c b/object.c
index dfaf765..6df578a 100644
--- a/object.c
+++ b/object.c
@@ -41,7 +41,6 @@ struct Symbol {
 
 typedef oop (*primitive_t)(oop params);
 
-oop globals;
 
 struct Function {
     type_t type;
@@ -158,7 +157,7 @@ int oopcmp(oop a, oop b)
         case String:
             return strcmp(get(a, String, value), get(b, String, value));
         case Symbol:
-            return strcmp(get(a, Symbol, name), get(b, Symbol, name));
+            return a - b;
         default:
             return (intptr_t)a - (intptr_t)b;
         }
@@ -260,26 +259,6 @@ oop map_append(oop map, oop value)
     return map_set(map, makeInteger(get(map, Map, size)), value);
 }
 
-bool variableIsDefined(oop aSymbol)
-{
-    assert(is(Symbol, aSymbol));
-    return map_hasKey(globals, aSymbol);
-}
-
-oop variableSet(oop aSymbol, oop value)
-{
-    assert(is(Symbol, aSymbol));
-    assert(value);
-    map_set(globals, aSymbol, value);
-    return value;
-}
-
-oop variableGet(oop aSymbol)
-{
-    assert(is(Symbol, aSymbol));
-    return map_get(globals, aSymbol);
-}
-
 void print(oop ast)
 {
     assert(ast);
@@ -323,14 +302,31 @@ void println(oop ast)
     printf("\n");
 }
 
-oop intern(oop scope, char *ident)
+oop symbol_table;
+
+ssize_t map_intern_search(oop map, char* ident)
 {
-    assert(is(Map, scope));
-    oop symbol = makeSymbol(memcheck(strdup(ident)));
-    ssize_t pos = map_search(scope, symbol);
-    if (pos >= 0) return get(scope, Map, elements)[pos].key; // So it this case, symbol will be garbage collected right?
+    assert(is(Map, map));
+    assert(ident);
+    ssize_t l = 0, r = get(map, Map, size) - 1;
+    while (l <= r) {
+        ssize_t mid = (l + r) / 2;
+        int cmpres = strcmp(get(get(map, Map, elements)[mid].key, Symbol, name), ident);
+        if (cmpres > 0)         r = mid - 1;
+        else if (cmpres < 0)    l = mid + 1;
+        else                    return mid; // non-negative result => element found at this index
+    }
+    return -1 - l; // negative result => 'not found', reflected around -1 instead of 0 to allow 'not found' at index 0
+}
+
+oop intern(char *ident)
+{
+    assert(ident);
+    ssize_t pos = map_intern_search(symbol_table, ident);
+    if (pos >= 0) return get(symbol_table, Map, elements)[pos].key;
     pos = -1 - pos; // 'un-negate' the result by reflecting it around X=-1
-    map_insert(scope, symbol, null, pos);
+    oop symbol = makeSymbol(memcheck(strdup(ident)));
+    map_insert(symbol_table, symbol, null, pos);
     return symbol;
 }
  
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