DEADSOFTWARE

Добавлена свёртка констант
authorDeaDDooMER <deaddoomer@deadsoftware.ru>
Sat, 12 Aug 2017 21:12:12 +0000 (00:12 +0300)
committerDeaDDooMER <deaddoomer@deadsoftware.ru>
Sat, 12 Aug 2017 21:12:12 +0000 (00:12 +0300)
Test.obn
Test10.obn
Test11.obn [new file with mode: 0644]
Test7.obn
obn-run-tests.sh
rtl/SYSTEM.java
src/backends/jvm/generator-jvm.c
src/oberon.c

index 4bde081725ba53658bd7868205734120600492d7..8371d40d26dc72bcfbac718753e7ba1e333de80b 100644 (file)
--- a/Test.obn
+++ b/Test.obn
@@ -2,22 +2,31 @@ MODULE Test;
 
 IMPORT Out;
 
+CONST
+  im1 = -1;
+  bol = ~FALSE;
+  set = { 1, 2, 3..6 };
+  fm1 = -1.0;
+  dm1 = -1.0D0;
+
 BEGIN
-  IF "abc" = "abc" THEN
-    Out.String("Equal abc = abc"); Out.Ln;
-  ELSE
-    Out.String("WAT: MUST BE abc = abc"); Out.Ln;
-  END;
+  Out.Open;
+
+  Out.Int(im1, 0); Out.Ln;
+  Out.Real(fm1, 0); Out.Ln;
+  Out.LongReal(dm1, 0); Out.Ln;
 
-  IF "cba" > "abc" THEN
-    Out.String("Great cba > abc"); Out.Ln;
+  IF 5 IN set THEN
+    Out.String("SET: Ok"); Out.Ln;
   ELSE
-    Out.String("WAT: MUST BE cba = abc"); Out.Ln;
+    Out.String("INVALID SET"); Out.Ln;
+    HALT(1);
   END;
 
-  IF "abc" < "bc" THEN
-    Out.String("Less abc < bc"); Out.Ln;
+  IF bol THEN
+    Out.String("BOOLEAN: Ok"); Out.Ln;
   ELSE
-    Out.String("WAT: MUST BE abc < bc"); Out.Ln;
+    Out.String("INVALID BOOLEAN"); Out.Ln;
+    HALT(1);
   END;
 END Test.
index 7b4b811f1f4edde36cd96d23481f2a8cd183b647..89dbcfd2f83a2e1d89937f8760d6dcab388e505c 100644 (file)
@@ -7,18 +7,21 @@ BEGIN
     Out.String("Equal abc = abc"); Out.Ln;
   ELSE
     Out.String("WAT: MUST BE abc = abc"); Out.Ln;
+    HALT(1);
   END;
 
   IF "cba" > "abc" THEN
     Out.String("Great cba > abc"); Out.Ln;
   ELSE
     Out.String("WAT: MUST BE cba = abc"); Out.Ln;
+    HALT(1);
   END;
 
   IF "abc" < "bc" THEN
     Out.String("Less abc < bc"); Out.Ln;
   ELSE
     Out.String("WAT: MUST BE abc < bc"); Out.Ln;
+    HALT(1);
   END;
 END Test10.
 
diff --git a/Test11.obn b/Test11.obn
new file mode 100644 (file)
index 0000000..847fddf
--- /dev/null
@@ -0,0 +1,39 @@
+MODULE Test11;
+
+IMPORT Out;
+
+CONST
+  im1 = -1;
+  bol = ~FALSE;
+  set = { 1, 2, 3..6 };
+  fm1 = -1.0;
+  dm1 = -1.0D0;
+  inf = 4 IN set;
+  rel = 10 = 100;
+  pi = 4 / 1 - 4 / 3 + 4 / 5 - 4 / 7 + 4 / 9 - 4 / 11 + 4 / 13 - 4 / 15 + 4 / 17 - 4 / 19 + 4 / 21;
+
+BEGIN
+  Out.Open;
+
+  Out.Int(im1, 0); Out.Ln;
+  Out.Real(fm1, 0); Out.Ln;
+  Out.LongReal(dm1, 0); Out.Ln;
+
+  Out.Real(pi, 0); Out.Ln;
+
+  IF 5 IN set THEN
+    Out.String("SET: Ok"); Out.Ln;
+  ELSE
+    Out.String("INVALID SET"); Out.Ln;
+    HALT(1);
+  END;
+
+  IF bol THEN
+    Out.String("BOOLEAN: Ok"); Out.Ln;
+  ELSE
+    Out.String("INVALID BOOLEAN"); Out.Ln;
+    HALT(1);
+  END;
+END Test11.
+
+Проверка свёртки констант.
index 739ec972c1c9ea3a5234bcb8b18c0aa3385df03d..7579867ca572312f8f4945516f7d4dbed0d1d0d4 100644 (file)
--- a/Test7.obn
+++ b/Test7.obn
@@ -4,14 +4,20 @@ IMPORT Out;
 
 VAR
   i : INTEGER;
+  ok : BOOLEAN;
 
 BEGIN
   Out.Open;
   i := 48;
   FOR i := 32 TO i DO
     Out.Int(i, 0); Out.Char(' ');
+    ok := TRUE;
   END;
   Out.Ln;
+
+  IF ok = FALSE THEN
+    HALT(1);
+  END;
 END Test7.
 
 Проверка корректности FOR.
index f9c6897afd21161e319c43176b2eaa406d553189..f483e01a2634ae6574da0e2a8ed8e7f4c00fc374 100755 (executable)
@@ -39,3 +39,4 @@ maketest Test7
 maketest Test8
 maketest Test9
 maketest Test10
+maketest Test11
index 68f82bd0983c3ee348507e7903023dc63318cf8c..28d8c466df99d528685380520b5429a2248a18e5 100644 (file)
@@ -19,16 +19,17 @@ public class SYSTEM
 
        public static void COPY(byte[] x, byte[] v)
        {
-               int len_x = LEN(x);
-               int len_v = v.length - 1;
+               int ix = LEN(x);
+               int iv = v.length - 1;
 
-               int len = (len_x < len_v) ? (len_x) : (len_v);
-               for(int i = 0; i < len; i++)
+               int i = 0;
+               int len = (ix < iv) ? (ix) : (iv);
+               while(i < len)
                {
                        v[i] = x[i];
+                       i += 1;
                }
-
-               v[len] = 0;
+               v[i] = 0;
        }
 
        public static int STRCMP(byte[] a, byte[] b)
index 189d8d275421b67a4fc2081d664c37ccf4149fc7..ee4bc67c17d31f33f25ba5047600658776953755 100644 (file)
@@ -1372,6 +1372,7 @@ jvm_generate_operator(gen_proc_t * p, oberon_type_t * t, int op)
                        jvm_generate(p, 2 * cell_size, cell_size, "%cand", prefix);
                        break;
                case OP_DIFFERENCE:
+                       /* (a - b) == a & ~b */
                        jvm_generate_push_int_size(p, -1, t -> size);
                        jvm_generate(p, 2 * cell_size, cell_size, "%cxor", prefix);
                        jvm_generate(p, 2 * cell_size, cell_size, "%cand", prefix);
@@ -1498,6 +1499,7 @@ jvm_generate_in(gen_proc_t * p, oberon_expr_t * a, oberon_expr_t * b)
        int label_else = jvm_new_label_id(p);
        int label_end = jvm_new_label_id(p);
 
+       /* (a IN b) == (1 << a) & b */
        jvm_generate_push_int_size(p, 1, t -> size);
        push_expr(p, a);
        jvm_generate(p, 2 * cell_size, cell_size, "%cshl", prefix);
index 6f9395ca71b81e1f8bf1254f9715a9568bf79610..30f10ec49af929465b3dfa31885ae7bb3b150fbb 100644 (file)
@@ -83,6 +83,119 @@ oberon_new_type_set(int size)
        return x;
 }
 
+static oberon_expr_t *
+oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon_expr_t * right)
+{
+       oberon_oper_t * operator;
+       operator = malloc(sizeof *operator);
+       memset(operator, 0, sizeof *operator);
+
+       operator -> is_item = 0;
+       operator -> result = result;
+       operator -> read_only = 1;
+       operator -> op = op;
+       operator -> left = left;
+       operator -> right = right;
+
+       return (oberon_expr_t *) operator;
+}
+
+static oberon_expr_t *
+oberon_new_item(int mode, oberon_type_t * result, int read_only)
+{
+       oberon_item_t * item;
+        item = malloc(sizeof *item);
+        memset(item, 0, sizeof *item);
+
+       item -> is_item = 1;
+       item -> result = result;
+       item -> read_only = read_only;
+       item -> mode = mode;
+
+       return (oberon_expr_t *)item;
+}
+
+static oberon_type_t *
+oberon_get_type_of_int_value(oberon_context_t * ctx, int64_t i)
+{
+       if(i >= -128 && i <= 127)
+       {
+               return ctx -> byte_type;
+       }
+       else if(i >= -32768 && i <= 32767)
+       {
+               return ctx -> shortint_type;
+       }
+       else if(i >= -2147483648 && i <= 2147483647)
+       {
+                return ctx -> int_type;
+       }
+       else
+       {
+               return ctx -> longint_type;
+       }
+}
+
+static oberon_expr_t *
+oberon_make_integer(oberon_context_t * ctx, int64_t i)
+{
+       oberon_expr_t * expr;
+       oberon_type_t * result;
+       result = oberon_get_type_of_int_value(ctx, i);
+       expr = oberon_new_item(MODE_INTEGER, result, true);
+       expr -> item.integer = i;
+       expr -> item.real = i;
+       return expr;
+}
+
+static oberon_expr_t *
+oberon_make_real_typed(oberon_context_t * ctx, double r, oberon_type_t * result)
+{
+       oberon_expr_t * expr;
+       expr = oberon_new_item(MODE_REAL, result, true);
+       expr -> item.integer = r;
+       expr -> item.real = r;
+       return expr;
+}
+
+static oberon_expr_t *
+oberon_make_real(oberon_context_t * ctx, double r, bool longmode)
+{
+       oberon_type_t * result;
+       result = (longmode) ? (ctx -> longreal_type) : (ctx -> real_type);
+       return oberon_make_real_typed(ctx, r, result);
+}
+
+static oberon_expr_t *
+oberon_make_boolean(oberon_context_t * ctx, bool cond)
+{
+       oberon_expr_t * expr;
+       expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, true);
+       expr -> item.integer = cond;
+       expr -> item.real = cond;
+       return expr;
+}
+
+static oberon_expr_t *
+oberon_make_set(oberon_context_t * ctx, int64_t i)
+{
+       oberon_expr_t * expr;
+       expr = oberon_new_item(MODE_SET, ctx -> set_type, true);
+       expr -> item.integer = i;
+       expr -> item.real = i;
+       return expr;
+}
+
+static oberon_expr_t *
+oberon_make_set_range(oberon_context_t * ctx, int64_t x, int64_t y)
+{
+       oberon_expr_t * expr;
+       expr = oberon_new_item(MODE_SET, ctx -> set_type, true);
+       expr -> item.integer = (x <= y) ? ((2 << y) - (1 << x)) : (0);
+       expr -> item.real = expr -> item.integer;
+       return expr;
+}
+
 // =======================================================================
 //   TABLE
 // ======================================================================= 
@@ -524,6 +637,7 @@ oberon_read_number(oberon_context_t * ctx)
                case 2:
                case 3:
                        sscanf(ident, "%lf", &real);
+                       integer = real;
                        ctx -> token = REAL;
                        break;
                case 4:
@@ -787,38 +901,7 @@ static char * oberon_assert_ident(oberon_context_t * ctx);
 static void oberon_type(oberon_context_t * ctx, oberon_type_t ** type);
 static oberon_item_t * oberon_const_expr(oberon_context_t * ctx);
 static oberon_expr_t * oberno_make_dereferencing(oberon_context_t * ctx, oberon_expr_t * expr);
-
-static oberon_expr_t *
-oberon_new_operator(int op, oberon_type_t * result, oberon_expr_t * left, oberon_expr_t * right)
-{
-       oberon_oper_t * operator;
-       operator = malloc(sizeof *operator);
-       memset(operator, 0, sizeof *operator);
-
-       operator -> is_item = 0;
-       operator -> result = result;
-       operator -> read_only = 1;
-       operator -> op = op;
-       operator -> left = left;
-       operator -> right = right;
-
-       return (oberon_expr_t *) operator;
-}
-
-static oberon_expr_t *
-oberon_new_item(int mode, oberon_type_t * result, int read_only)
-{
-       oberon_item_t * item;
-        item = malloc(sizeof *item);
-        memset(item, 0, sizeof *item);
-
-       item -> is_item = 1;
-       item -> result = result;
-       item -> read_only = read_only;
-       item -> mode = mode;
-
-       return (oberon_expr_t *)item;
-}
+static bool oberon_is_const(oberon_expr_t * expr);
 
 static oberon_expr_t *
 oberon_make_unary_op(oberon_context_t * ctx, int token, oberon_expr_t * a)
@@ -832,11 +915,36 @@ oberon_make_unary_op(oberon_context_t * ctx, int token, oberon_expr_t * a)
        {
                if(result -> class == OBERON_TYPE_SET)
                {
-                       expr = oberon_new_operator(OP_COMPLEMENTATION, result, a, NULL);
+                       if(oberon_is_const(a))
+                       {
+                               expr = oberon_make_set(ctx, ~(a -> item.integer));
+                       }
+                       else
+                       {
+                               expr = oberon_new_operator(OP_COMPLEMENTATION, result, a, NULL);
+                       }
                }
                else if(result -> class == OBERON_TYPE_INTEGER)
                {
-                       expr = oberon_new_operator(OP_UNARY_MINUS, result, a, NULL);
+                       if(oberon_is_const(a))
+                       {
+                               expr = oberon_make_integer(ctx, -(a -> item.integer));
+                       }
+                       else
+                       {
+                               expr = oberon_new_operator(OP_UNARY_MINUS, result, a, NULL);
+                       }
+               }
+               else if(result -> class == OBERON_TYPE_REAL)
+               {
+                       if(oberon_is_const(a))
+                       {
+                               expr = oberon_make_real_typed(ctx, -(a -> item.real), result);
+                       }
+                       else
+                       {
+                               expr = oberon_new_operator(OP_UNARY_MINUS, result, a, NULL);
+                       }
                }
                else
                {
@@ -850,7 +958,14 @@ oberon_make_unary_op(oberon_context_t * ctx, int token, oberon_expr_t * a)
                        oberon_error(ctx, "incompatible operator type");
                }
 
-               expr = oberon_new_operator(OP_LOGIC_NOT, result, a, NULL);
+                       if(oberon_is_const(a))
+                       {
+                               expr = oberon_make_boolean(ctx, !(a -> item.integer));
+                       }
+                       else
+                       {
+                               expr = oberon_new_operator(OP_LOGIC_NOT, result, a, NULL);
+                       }
        }
        else
        {
@@ -1415,38 +1530,6 @@ oberon_opt_proc_parens(oberon_context_t * ctx, oberon_expr_t * expr)
        oberon_make_call_proc(ctx, (oberon_item_t *) expr, num_args, arguments);
 }
 
-static oberon_type_t *
-oberon_get_type_of_int_value(oberon_context_t * ctx, int64_t i)
-{
-       if(i >= -128 && i <= 127)
-       {
-               return ctx -> byte_type;
-       }
-       else if(i >= -32768 && i <= 32767)
-       {
-               return ctx -> shortint_type;
-       }
-       else if(i >= -2147483648 && i <= 2147483647)
-       {
-                return ctx -> int_type;
-       }
-       else
-       {
-               return ctx -> longint_type;
-       }
-}
-
-static oberon_expr_t *
-oberon_integer_item(oberon_context_t * ctx, int64_t i)
-{
-       oberon_expr_t * expr;
-       oberon_type_t * result;
-       result = oberon_get_type_of_int_value(ctx, i);
-       expr = oberon_new_item(MODE_INTEGER, result, true);
-       expr -> item.integer = i;
-       return expr;
-}
-
 static oberon_expr_t *
 oberon_element(oberon_context_t * ctx)
 {
@@ -1473,28 +1556,51 @@ oberon_element(oberon_context_t * ctx)
        }
 
        oberon_expr_t * set;
-       set = oberon_new_operator(OP_RANGE, ctx -> set_type, e1, e2);
+       if(e2 == NULL && oberon_is_const(e1))
+       {
+               set = oberon_make_set(ctx, e1 -> item.integer);
+       }
+       else if(e2 != NULL && oberon_is_const(e1) && oberon_is_const(e2))
+       {
+               set = oberon_make_set_range(ctx, e1 -> item.integer, e2 -> item.integer);
+       }
+       else
+       {
+               set = oberon_new_operator(OP_RANGE, ctx -> set_type, e1, e2);
+       }
        return set;
 }
 
+static oberon_expr_t *
+oberon_make_set_union(oberon_context_t * ctx, oberon_expr_t * a, oberon_expr_t * b)
+{
+       if(oberon_is_const(a) && oberon_is_const(b))
+       {
+               return oberon_make_set(ctx, (a -> item.integer | b -> item.integer));
+       }
+       else
+       {
+               return oberon_new_operator(OP_UNION, ctx -> set_type, a, b);
+       }       
+}
+
 static oberon_expr_t *
 oberon_set(oberon_context_t * ctx)
 {
        oberon_expr_t * set;
        oberon_expr_t * elements;
-       set = oberon_new_item(MODE_SET, ctx -> set_type, true);
-       set -> item.integer = 0;
+       set = oberon_make_set(ctx, 0);
 
        oberon_assert_token(ctx, LBRACE);
        if(ISEXPR(ctx -> token))
        {
                elements = oberon_element(ctx);
-               set = oberon_new_operator(OP_UNION, ctx -> set_type, set, elements);
+               set = oberon_make_set_union(ctx, set, elements);
                while(ctx -> token == COMMA)
                {
                        oberon_assert_token(ctx, COMMA);
                        elements = oberon_element(ctx);
-                       set = oberon_new_operator(OP_UNION, ctx -> set_type, set, elements);
+                       set = oberon_make_set_union(ctx, set, elements);
                }
        }
        oberon_assert_token(ctx, RBRACE);
@@ -1502,15 +1608,6 @@ oberon_set(oberon_context_t * ctx)
        return set;
 }
 
-static oberon_expr_t *
-oberon_make_boolean(oberon_context_t * ctx, bool cond)
-{
-       oberon_expr_t * expr;
-       expr = oberon_new_item(MODE_BOOLEAN, ctx -> bool_type, true);
-       expr -> item.integer = cond;
-       return expr;
-}
-
 static oberon_expr_t *
 oberon_factor(oberon_context_t * ctx)
 {
@@ -1524,7 +1621,7 @@ oberon_factor(oberon_context_t * ctx)
                        expr = oberon_opt_func_parens(ctx, expr);
                        break;
                case INTEGER:
-                       expr = oberon_integer_item(ctx, ctx -> integer);
+                       expr = oberon_make_integer(ctx, ctx -> integer);
                        oberon_assert_token(ctx, INTEGER);
                        break;
                case CHAR:
@@ -1540,9 +1637,7 @@ oberon_factor(oberon_context_t * ctx)
                        oberon_assert_token(ctx, STRING);
                        break;
                case REAL:
-                       result = (ctx -> longmode) ? (ctx -> longreal_type) : (ctx -> real_type);
-                       expr = oberon_new_item(MODE_REAL, result, 1);
-                       expr -> item.real = ctx -> real;
+                       expr = oberon_make_real(ctx, ctx -> real, ctx -> longmode);
                        oberon_assert_token(ctx, REAL);
                        break;
                case LBRACE:
@@ -1582,10 +1677,16 @@ oberon_make_bin_op(oberon_context_t * ctx, int token, oberon_expr_t * a, oberon_
                oberon_check_src(ctx, b);
        }
 
-       bool error = false;
        if(token == IN)
        {
-               expr = oberon_new_operator(OP_IN, ctx -> bool_type, a, b);
+               if(oberon_is_const(a) && oberon_is_const(b))
+               {
+                       expr = oberon_make_boolean(ctx, (1 << a -> item.integer) & b -> item.integer);
+               }
+               else
+               {
+                       expr = oberon_new_operator(OP_IN, ctx -> bool_type, a, b);
+               }
        }
        else if(token == IS)
        {
@@ -1595,126 +1696,201 @@ oberon_make_bin_op(oberon_context_t * ctx, int token, oberon_expr_t * a, oberon_
        else if((token >= EQUAL && token <= GEQ) || token == OR || token == AND)
        {
                result = oberon_get_longer_type(ctx, a -> result, b -> result);
-               a = oberon_cast_expr(ctx, a, result);
-               b = oberon_cast_expr(ctx, b, result);
-               result = ctx -> bool_type;
 
-               if(token == EQUAL)
-               {
-                       expr = oberon_new_operator(OP_EQ, result, a, b);
-               }
-               else if(token == NEQ)
-               {
-                       expr = oberon_new_operator(OP_NEQ, result, a, b);
-               }
-               else if(token == LESS)
-               {
-                       expr = oberon_new_operator(OP_LSS, result, a, b);
-               }
-               else if(token == LEQ)
-               {
-                       expr = oberon_new_operator(OP_LEQ, result, a, b);
-               }
-               else if(token == GREAT)
-               {
-                       expr = oberon_new_operator(OP_GRT, result, a, b);
-               }
-               else if(token == GEQ)
-               {
-                       expr = oberon_new_operator(OP_GEQ, result, a, b);
-               }
-               else if(token == OR)
-               {
-                       expr = oberon_new_operator(OP_LOGIC_OR, result, a, b);
-               }
-               else if(token == AND)
+               if(oberon_is_const(a) && oberon_is_const(b)
+                       && (oberon_is_real_type(result) || oberon_is_integer_type(result)))
                {
-                       expr = oberon_new_operator(OP_LOGIC_AND, result, a, b);
+                       if(oberon_is_real_type(result))
+                       {
+                               double x = a -> item.real;
+                               double y = b -> item.real;
+                               switch(token)
+                               {
+                                       case EQUAL: expr = oberon_make_boolean(ctx, x == y); break;
+                                       case NEQ:   expr = oberon_make_boolean(ctx, x != y); break;
+                                       case LESS:  expr = oberon_make_boolean(ctx, x < y); break;
+                                       case LEQ:   expr = oberon_make_boolean(ctx, x <= y); break;
+                                       case GREAT: expr = oberon_make_boolean(ctx, x > y); break;
+                                       case GEQ:   expr = oberon_make_boolean(ctx, x >= y); break;
+                                       case OR:    expr = oberon_make_boolean(ctx, x || y); break;
+                                       case AND:   expr = oberon_make_boolean(ctx, x && y); break;
+                                       default: assert(0); break;
+                               }
+                       }
+                       else if(oberon_is_integer_type(result))
+                       {
+                               int64_t x = a -> item.integer;
+                               int64_t y = b -> item.integer;
+                               switch(token)
+                               {
+                                       case EQUAL: expr = oberon_make_boolean(ctx, x == y); break;
+                                       case NEQ:   expr = oberon_make_boolean(ctx, x != y); break;
+                                       case LESS:  expr = oberon_make_boolean(ctx, x < y); break;
+                                       case LEQ:   expr = oberon_make_boolean(ctx, x <= y); break;
+                                       case GREAT: expr = oberon_make_boolean(ctx, x > y); break;
+                                       case GEQ:   expr = oberon_make_boolean(ctx, x >= y); break;
+                                       case OR:    expr = oberon_make_boolean(ctx, x || y); break;
+                                       case AND:   expr = oberon_make_boolean(ctx, x && y); break;
+                                       default: assert(0); break;
+                               }
+                       }
+                       else
+                       {
+                               assert(0);
+                       }
                }
                else
                {
-                       oberon_error(ctx, "oberon_make_bin_op: bool wat");
+                       a = oberon_cast_expr(ctx, a, result);
+                       b = oberon_cast_expr(ctx, b, result);
+                       result = ctx -> bool_type;
+                       switch(token)
+                       {
+                               case EQUAL: expr = oberon_new_operator(OP_EQ, result, a, b); break;
+                               case NEQ:   expr = oberon_new_operator(OP_NEQ, result, a, b); break;
+                               case LESS:  expr = oberon_new_operator(OP_LSS, result, a, b); break;
+                               case LEQ:   expr = oberon_new_operator(OP_LEQ, result, a, b); break;
+                               case GREAT: expr = oberon_new_operator(OP_GRT, result, a, b); break;
+                               case GEQ:   expr = oberon_new_operator(OP_GEQ, result, a, b); break;
+                               case OR:    expr = oberon_new_operator(OP_LOGIC_OR, result, a, b); break;
+                               case AND:   expr = oberon_new_operator(OP_LOGIC_AND, result, a, b); break;
+                               default: assert(0); break;
+                       }
                }
        }
        else if(token == SLASH)
        {
                if(oberon_is_set_type(a -> result) && oberon_is_set_type(b -> result))
                {
-                       result = oberon_get_longer_type(ctx, a -> result, b -> result);
-                       a = oberon_cast_expr(ctx, a, result);
-                       b = oberon_cast_expr(ctx, b, result);
-                       expr = oberon_new_operator(OP_SYM_DIFFERENCE, result, a, b);
+                       if(oberon_is_const(a) && oberon_is_const(b))
+                       {
+                               int64_t x = a -> item.integer;
+                               int64_t y = b -> item.integer;
+                               expr = oberon_make_set(ctx, x ^ y);
+                       }
+                       else
+                       {
+                               result = oberon_get_longer_type(ctx, a -> result, b -> result);
+                               a = oberon_cast_expr(ctx, a, result);
+                               b = oberon_cast_expr(ctx, b, result);
+                               expr = oberon_new_operator(OP_SYM_DIFFERENCE, result, a, b);
+                       }
                }
                else
                {
                        result = oberon_get_longer_real_type(ctx, a -> result, b -> result);
-                       a = oberon_cast_expr(ctx, a, result);
-                       b = oberon_cast_expr(ctx, b, result);
-                       expr = oberon_new_operator(OP_DIV, result, a, b);
+                       if(oberon_is_const(a) && oberon_is_const(b))
+                       {
+                               double x = a -> item.real;
+                               double y = b -> item.real;
+                               expr = oberon_make_real_typed(ctx, x / y, result);
+                       }
+                       else
+                       {
+                               a = oberon_cast_expr(ctx, a, result);
+                               b = oberon_cast_expr(ctx, b, result);
+                               expr = oberon_new_operator(OP_DIV, result, a, b);
+                       }
                }
        }
-       else if(token == DIV)
-       {
-               result = oberon_get_longer_type(ctx, a -> result, b -> result);
-               a = oberon_cast_expr(ctx, a, result);
-               b = oberon_cast_expr(ctx, b, result);
-               expr = oberon_new_operator(OP_DIV, result, a, b);
-       }
        else
        {
                result = oberon_get_longer_type(ctx, a -> result, b -> result);
-               a = oberon_cast_expr(ctx, a, result);
-               b = oberon_cast_expr(ctx, b, result);
-               if(oberon_is_set_type(result))
+
+               if(oberon_is_const(a) && oberon_is_const(b))
                {
-                       switch(token)
+                       if(oberon_is_set_type(result))
                        {
-                               case PLUS:
-                                       expr = oberon_new_operator(OP_UNION, result, a, b);
-                                       break;
-                               case MINUS:
-                                       expr = oberon_new_operator(OP_DIFFERENCE, result, a, b);
-                                       break;
-                               case STAR:
-                                       expr = oberon_new_operator(OP_INTERSECTION, result, a, b);
-                                       break;
-                               default:
-                                       error = true;
-                                       break;
+                               int64_t x = a -> item.integer;
+                               int64_t y = b -> item.integer;
+                               switch(token)
+                               {
+                                       case PLUS:  expr = oberon_make_set(ctx, x | y); break;
+                                       case MINUS: expr = oberon_make_set(ctx, x & ~y); break;
+                                       case STAR:  expr = oberon_make_set(ctx, x & y); break;
+                                       default: assert(0); break;
+                               }
                        }
-               }
-               else if(oberon_is_number_type(result))
-               {
-                       switch(token)
+                       if(oberon_is_real_type(result))
                        {
-                               case PLUS:
-                                       expr = oberon_new_operator(OP_ADD, result, a, b);
-                                       break;
-                               case MINUS:
-                                       expr = oberon_new_operator(OP_SUB, result, a, b);
-                                       break;
-                               case STAR:
-                                       expr = oberon_new_operator(OP_MUL, result, a, b);
-                                       break;
-                               case MOD:
-                                       expr = oberon_new_operator(OP_MOD, result, a, b);
-                                       break;
-                               default:
-                                       error = true;
-                                       break;
+                               double x = a -> item.real;
+                               double y = b -> item.real;
+                               switch(token)
+                               {
+                                       case PLUS:  expr = oberon_make_real_typed(ctx, x + y, result); break;
+                                       case MINUS: expr = oberon_make_real_typed(ctx, x - y, result); break;
+                                       case STAR:  expr = oberon_make_real_typed(ctx, x * y, result); break;
+                                       default: assert(0); break;
+                               }
+                       }
+                       else if(oberon_is_integer_type(result))
+                       {
+                               int64_t x = a -> item.integer;
+                               int64_t y = b -> item.integer;
+                               switch(token)
+                               {
+                                       case PLUS:  expr = oberon_make_integer(ctx, x + y); break;
+                                       case MINUS: expr = oberon_make_integer(ctx, x - y); break;
+                                       case STAR:  expr = oberon_make_integer(ctx, x * y); break;
+                                       case DIV:   expr = oberon_make_integer(ctx, x / y); break;
+                                       case MOD:   expr = oberon_make_integer(ctx, x % y); break;
+                                       default: assert(0); break;
+                               }
+                       }
+                       else
+                       {
+                               assert(0);
                        }
                }
                else
                {
-                       error = true;
+                       a = oberon_cast_expr(ctx, a, result);
+                       b = oberon_cast_expr(ctx, b, result);
+                       
+                       
+                       if(oberon_is_set_type(result))
+                       {
+                               switch(token)
+                               {
+                                       case PLUS:
+                                               expr = oberon_new_operator(OP_UNION, result, a, b);
+                                               break;
+                                       case MINUS:
+                                               expr = oberon_new_operator(OP_DIFFERENCE, result, a, b);
+                                               break;
+                                       case STAR:
+                                               expr = oberon_new_operator(OP_INTERSECTION, result, a, b);
+                                               break;
+                                       default:
+                                               assert(0);
+                                               break;
+                               }
+                       }
+                       else if(oberon_is_number_type(result))
+                       {
+                               switch(token)
+                               {
+                                       case PLUS:
+                                               expr = oberon_new_operator(OP_ADD, result, a, b);
+                                               break;
+                                       case MINUS:
+                                               expr = oberon_new_operator(OP_SUB, result, a, b);
+                                               break;
+                                       case STAR:
+                                               expr = oberon_new_operator(OP_MUL, result, a, b);
+                                               break;
+                                       default:
+                                               assert(0);
+                                               break;
+                               }
+                       }
+                       else
+                       {
+                               assert(0);
+                       }
                }
        }
 
-       if(error)
-       {
-               oberon_error(ctx, "invalid operation");
-       }
-
        return expr;
 }
 
@@ -1799,12 +1975,12 @@ oberon_expr(oberon_context_t * ctx)
        return expr;
 }
 
-static void
-oberon_check_const(oberon_context_t * ctx, oberon_expr_t * expr)
+static bool
+oberon_is_const(oberon_expr_t * expr)
 {
-       if(expr -> is_item == 0)
+       if(expr -> is_item == false)
        {
-               oberon_error(ctx, "const expression are required");
+               return false;
        }
 
        switch(expr -> item.mode)
@@ -1815,13 +1991,25 @@ oberon_check_const(oberon_context_t * ctx, oberon_expr_t * expr)
                case MODE_REAL:
                case MODE_CHAR:
                case MODE_STRING:
+               case MODE_SET:
                case MODE_TYPE:
-                       /* accept */
+                       return true;
                        break;
                default:
-                       oberon_error(ctx, "const expression are required");
+                       return false;
                        break;
        }
+
+       return false;
+}
+
+static void
+oberon_check_const(oberon_context_t * ctx, oberon_expr_t * expr)
+{
+       if(!oberon_is_const(expr))
+       {
+               oberon_error(ctx, "const expression are required");
+       }
 }
 
 static oberon_item_t *
@@ -3212,7 +3400,7 @@ oberon_statement(oberon_context_t * ctx)
                }
                else
                {
-                       by = oberon_integer_item(ctx, 1);
+                       by = oberon_make_integer(ctx, 1);
                }
 
                if(by -> result -> class != OBERON_TYPE_INTEGER)
@@ -3491,10 +3679,10 @@ oberon_make_min_call(oberon_context_t * ctx, int num_args, oberon_expr_t * list_
        switch(arg -> result -> class)
        {
                case OBERON_TYPE_INTEGER:
-                       expr = oberon_integer_item(ctx, -powl(2, bits - 1));
+                       expr = oberon_make_integer(ctx, -powl(2, bits - 1));
                        break;
                case OBERON_TYPE_SET:
-                       expr = oberon_integer_item(ctx, 0);
+                       expr = oberon_make_integer(ctx, 0);
                        break;
                default:
                        oberon_error(ctx, "allowed only basic types");
@@ -3530,10 +3718,10 @@ oberon_make_max_call(oberon_context_t * ctx, int num_args, oberon_expr_t * list_
        switch(arg -> result -> class)
        {
                case OBERON_TYPE_INTEGER:
-                       expr = oberon_integer_item(ctx, powl(2, bits - 1) - 1);
+                       expr = oberon_make_integer(ctx, powl(2, bits - 1) - 1);
                        break;
                case OBERON_TYPE_SET:
-                       expr = oberon_integer_item(ctx, bits);
+                       expr = oberon_make_integer(ctx, bits);
                        break;
                default:
                        oberon_error(ctx, "allowed only basic types");
@@ -3581,7 +3769,7 @@ oberon_make_size_call(oberon_context_t * ctx, int num_args, oberon_expr_t * list
                        break;
        }
 
-       expr = oberon_integer_item(ctx, size);
+       expr = oberon_make_integer(ctx, size);
        return expr;
 }