add increment/decrement operators

bootstrap/emit.cc

@@ -190,6 +190,20 @@ std::any EmitVisitor::visitVariable(xlangParser::VariableContext *ctx) {
     last = "%_" + name;
     return {};
   }
+  if (ctx->Increment()) {
+    visitExpr(ctx->expr());
+    output << "  %_" << name << " = w add %_" << name << ", " << last
+           << std::endl;
+    last = "%_" + name;
+    return {};
+  }
+  if (ctx->Decrement()) {
+    visitExpr(ctx->expr());
+    output << "  %_" << name << " = w sub %_" << name << ", " << last
+           << std::endl;
+    last = "%_" + name;
+    return {};
+  }
   if (ctx->LeftParen()) {
     std::vector<std::string> args;
 

bootstrap/typecheck.cc

@@ -230,6 +230,21 @@ std::any TypeCheckVisitor::visitVariable(xlangParser::VariableContext *ctx) {
       return type;
     }
   }
+  if (auto expr = ctx->expr()) {
+    auto righttype = std::any_cast<Type>(visitExpr(expr));
+
+    if (auto lefttype = scope.get(name)) {
+      if (*lefttype != Type::Integer) {
+        errorlistener.typeMismatch(token, Type::Integer, *lefttype);
+      }
+    } else {
+      errorlistener.unknownVariable(token, name);
+    }
+    if (righttype != Type::Integer) {
+      errorlistener.typeMismatch(token, Type::Integer, righttype);
+    }
+    return Type::Integer;
+  }
   if (ctx->LeftParen()) {
     auto it = signatures.find(name);
 

bootstrap/xlang.g4

@@ -43,6 +43,8 @@ factor  : Minus factor
 variable  : Identifier
           | Identifier Define value
           | Identifier Assign value
+          | Identifier Increment expr
+          | Identifier Decrement expr
           | Identifier LeftParen argumentList? RightParen
           ;
 argumentList  : value (Comma value)*;
@@ -87,6 +89,8 @@ BitNot  : '~';
 Mul : '*';
 Div : '/';
 Rem : '%';
+Increment : '=+';
+Decrement : '=-';
 Comma : ',';
 Semicolon : ';';
 

test/fib.x

@@ -3,7 +3,7 @@ main() : int {
   while i < 10 {
     print fib_rec(i);
     print fib_iter(i);
-    i = i + 1;
+    i =+ 1;
   }
 }
 
@@ -22,7 +22,7 @@ fib_iter(n : int) : int {
     t := x0 + x1;
     x0 = x1;
     x1 = t;
-    i = i + 1;
+    i =+ 1;
   }
   return x0;
 }

test/sieve.x

@@ -9,11 +9,11 @@ main() : int {
         composite = true;
         break;
       }
-      j = j + 2;
+      j =+ 2;
     }
     if not composite {
       print i;
     }
-    i = i + 2;
+    i =+ 2;
   }
 }