[Tolk] Allow cell and slice be valid identifiers

They are not keywords anymore.
> var cell = ...;
> var cell: cell = ...;
Motivation: in the future, when structures are implemented, this obviously should be valid:
> struct a { ... }
> var a = ...;
Struct fields will also be allowed to have names int/slice/cell.

tolk-tester/tests/assignment-tests.tolk

@@ -14,6 +14,18 @@ fun autoInferIntNull(x: int) {
     return x;
 }
 
+fun typesAsIdentifiers(builder: builder) {
+    var int = 1;
+    var cell = builder.endCell();
+    var slice = cell.beginParse();
+    {
+        var cell: cell = cell;
+        var tuple: tuple = createEmptyTuple();
+        var bool: bool = tuple.tupleAt<int>(0) > 0;
+    }
+    return int;
+}
+
 fun main(value: int) {
     var (x: int, y) = (autoInferIntNull(value), autoInferIntNull(value * 2));
     if (x == null && y == null) { return null; }

tolk-tester/tests/invalid-catch-1.tolk

@@ -1,12 +1,12 @@
 fun main() {
     try {
 
-    } catch(int, arg) {}
+    } catch(if, arg) {}
     return 0;
 }
 
 /**
 @compilation_should_fail
-@stderr expected identifier, got `int`
-@stderr catch(int
+@stderr expected identifier, got `if`
+@stderr catch(if
  */

tolk-tester/tests/invalid-declaration-2.tolk

@@ -4,5 +4,5 @@ fun main(int): int {
 
 /**
 @compilation_should_fail
-@stderr expected parameter name, got `int`
+@stderr expected `: <parameter_type>`, got `)`
 */

tolk-tester/tests/invalid-declaration-4.tolk

@@ -4,5 +4,5 @@ fun main() {
 
 /**
 @compilation_should_fail
-@stderr probably, you use FunC-like declarations; valid syntax is `var x: int = ...`
+@stderr expected `;`, got `x`
 */

tolk-tester/tests/method_id.tolk

@@ -4,6 +4,8 @@ fun foo1(): int { return 111; }
 fun foo2(): int { return 222; }
 @method_id(10)
 fun foo3(): int { return 333; }
+@method_id(11)
+fun slice(slice: slice): slice { return slice; }
 fun main(): int { return 999; }
 
 /**

tolk/ast-from-tokens.cpp

@@ -111,16 +111,6 @@ static void diagnose_addition_in_bitshift(SrcLocation loc, std::string_view bits
   }
 }
 
-// fire an error for FunC-style variable declaration, like "int i"
-GNU_ATTRIBUTE_NORETURN GNU_ATTRIBUTE_COLD
-static void fire_error_FunC_style_var_declaration(Lexer& lex) {
-  SrcLocation loc = lex.cur_location();
-  std::string type_str = static_cast<std::string>(lex.cur_str());      // int / slice / etc.
-  lex.next();
-  std::string var_name = lex.tok() == tok_identifier ? static_cast<std::string>(lex.cur_str()) : "name";
-  throw ParseError(loc, "can't parse; probably, you use FunC-like declarations; valid syntax is `var " + var_name + ": " + type_str + " = ...`");
-}
-
 // replace (a == null) and similar to isNull(a) (call of a built-in function)
 static AnyExprV maybe_replace_eq_null_with_isNull_call(V<ast_binary_operator> v) {
   bool has_null = v->get_lhs()->type == ast_null_keyword || v->get_rhs()->type == ast_null_keyword;
@@ -377,14 +367,8 @@ static AnyExprV parse_expr100(Lexer& lex) {
       }
       return createV<ast_reference>(loc, v_ident, v_instantiationTs);
     }
-    default: {
-      // show a proper error for `int i` (FunC-style declarations)
-      TokenType t = lex.tok();
-      if (t == tok_int || t == tok_cell || t == tok_slice || t == tok_builder || t == tok_tuple) {
-        fire_error_FunC_style_var_declaration(lex);
-      }
+    default:
       lex.unexpected("<expression>");
-    }
   }
 }
 

tolk/lexer.cpp

@@ -331,7 +331,6 @@ struct ChunkIdentifierOrKeyword final : ChunkLexerBase {
         if (str == "as") return tok_as;
         break;
       case 3:
-        if (str == "int") return tok_int;
         if (str == "var") return tok_var;
         if (str == "fun") return tok_fun;
         if (str == "asm") return tok_asm;
@@ -342,18 +341,13 @@ struct ChunkIdentifierOrKeyword final : ChunkLexerBase {
       case 4:
         if (str == "else") return tok_else;
         if (str == "true") return tok_true;
-        if (str == "cell") return tok_cell;
         if (str == "null") return tok_null;
-        if (str == "void") return tok_void;
-        if (str == "bool") return tok_bool;
         if (str == "self") return tok_self;
         if (str == "tolk") return tok_tolk;
         if (str == "type") return tok_type;
         if (str == "enum") return tok_enum;
         break;
       case 5:
-        if (str == "slice") return tok_slice;
-        if (str == "tuple") return tok_tuple;
         if (str == "const") return tok_const;
         if (str == "false") return tok_false;
         if (str == "redef") return tok_redef;
@@ -374,16 +368,12 @@ struct ChunkIdentifierOrKeyword final : ChunkLexerBase {
         if (str == "export") return tok_export;
         break;
       case 7:
-        if (str == "builder") return tok_builder;
         if (str == "builtin") return tok_builtin;
         break;
       case 8:
         if (str == "continue") return tok_continue;
         if (str == "operator") return tok_operator;
         break;
-      case 12:
-        if (str == "continuation") return tok_continuation;
-        break;
       default:
         break;
     }

tolk/lexer.h

@@ -118,14 +118,6 @@ enum TokenType {
   tok_if,
   tok_else,
 
-  tok_int,
-  tok_cell,
-  tok_bool,
-  tok_slice,
-  tok_builder,
-  tok_continuation,
-  tok_tuple,
-  tok_void,
   tok_arrow,
   tok_as,
 

tolk/type-system.cpp

@@ -581,40 +581,38 @@ std::vector<TypePtr> parse_nested_type_list_in_parenthesis(Lexer& lex) {
 
 static TypePtr parse_simple_type(Lexer& lex) {
   switch (lex.tok()) {
-    case tok_int:
-      lex.next();
-      return TypeDataInt::create();
-    case tok_bool:
-      lex.next();
-      return TypeDataBool::create();
-    case tok_cell:
-      lex.next();
-      return TypeDataCell::create();
-    case tok_builder:
-      lex.next();
-      return TypeDataBuilder::create();
-    case tok_slice:
-      lex.next();
-      return TypeDataSlice::create();
-    case tok_tuple:
-      lex.next();
-      return TypeDataTuple::create();
-    case tok_continuation:
-      lex.next();
-      return TypeDataContinuation::create();
-    case tok_null:
-      lex.next();
-      return TypeDataNullLiteral::create();
-    case tok_void:
-      lex.next();
-      return TypeDataVoid::create();
     case tok_self:
     case tok_identifier: {
       SrcLocation loc = lex.cur_location();
-      std::string text = static_cast<std::string>(lex.cur_str());
+      std::string_view str = lex.cur_str();
       lex.next();
-      return TypeDataUnresolved::create(std::move(text), loc);
+      switch (str.size()) {
+        case 3:
+          if (str == "int") return TypeDataInt::create();
+          break;
+        case 4:
+          if (str == "cell") return TypeDataCell::create();
+          if (str == "void") return TypeDataVoid::create();
+          if (str == "bool") return TypeDataBool::create();
+          break;
+        case 5:
+          if (str == "slice") return TypeDataSlice::create();
+          if (str == "tuple") return TypeDataTuple::create();
+          break;
+        case 7:
+          if (str == "builder") return TypeDataBuilder::create();
+          break;
+        case 12:
+          if (str == "continuation") return TypeDataContinuation::create();
+          break;
+        default:
+          break;
+      }
+      return TypeDataUnresolved::create(std::string(str), loc);
     }
+    case tok_null:
+      lex.next();
+      return TypeDataNullLiteral::create();
     case tok_oppar: {
       std::vector<TypePtr> items = parse_nested_type_list_in_parenthesis(lex);
       if (items.size() == 1) {