Refactor: don't treat '<' as a binary-only operator

QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL and QLJS_CASE_BINARY_ONLY_OPERATOR
include '<'. This is wrong, because '<' is also used to start a JSX
expression. Remove '<' from QLJS_CASE_BINARY_ONLY_OPERATOR[_SYMBOL], and
explicitly mention '<' in all uses of
QLJS_CASE_BINARY_ONLY_OPERATOR[_SYMBOL].

Relatedly, rename
QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_LESS_AND_STAR to
QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_STAR.

This commit should not change behavior.

Author: strager

src/parse.cpp

@@ -455,6 +455,7 @@ bool parser::is_let_token_a_variable_reference(
   case token_type::equal_greater:
   case token_type::incomplete_template:
   case token_type::left_paren:
+  case token_type::less:
   case token_type::minus:
   case token_type::minus_minus:
   case token_type::plus:

src/quick-lint-js/parse-expression-inl.h

@@ -600,6 +600,7 @@ expression* parser::parse_primary_expression(Visitor& v, precedence prec) {
   case token_type::dot:
   case token_type::equal:
   case token_type::kw_in:
+  case token_type::less:
   case token_type::question: {
     if (this->peek().type == token_type::star) {
       token star_token = this->peek();
@@ -885,6 +886,12 @@ expression* parser::parse_await_expression(Visitor& v, token await_token,
       case token_type::semicolon:
         return true;
 
+      // await <x>y</x>/g  // operator
+      // await < other    // identifier
+      case token_type::less:
+        // TODO(strager): Resolve the ambiguity.
+        return true;
+
       // await /regexp/;
       // await / rhs;
       case token_type::slash:
@@ -1063,6 +1070,7 @@ expression* parser::parse_expression_remainder(Visitor& v, expression* ast,
 
   // x + y
   QLJS_CASE_BINARY_ONLY_OPERATOR:
+  case token_type::less:
   case token_type::minus:
   case token_type::plus:
   case token_type::slash: {
@@ -1248,11 +1256,12 @@ expression* parser::parse_expression_remainder(Visitor& v, expression* ast,
     case token_type::end_of_file:
     case token_type::equal:
     case token_type::left_paren:
+    case token_type::less:
     case token_type::minus:
     case token_type::plus:
     case token_type::question:
-    case token_type::semicolon:
-    case token_type::right_paren: {
+    case token_type::right_paren:
+    case token_type::semicolon: {
       source_code_span empty_property_name(dot_span.end(), dot_span.end());
       binary_builder.replace_last(this->make_expression<expression::dot>(
           binary_builder.last_expression(), identifier(empty_property_name)));
@@ -2143,7 +2152,7 @@ expression* parser::parse_object_literal(Visitor& v) {
 
       // {x += y}  // Invalid.
       expression_without_key:
-      QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_LESS_AND_STAR:
+      QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_STAR:
       QLJS_CASE_COMPOUND_ASSIGNMENT_OPERATOR:
       QLJS_CASE_CONDITIONAL_ASSIGNMENT_OPERATOR:
       case token_type::dot:

src/quick-lint-js/parse-statement-inl.h

@@ -159,6 +159,7 @@ bool parser::parse_and_visit_statement(
     case token_type::kw_in:
     case token_type::kw_yield:
     case token_type::left_paren:
+    case token_type::less:
     case token_type::minus:
     case token_type::minus_minus:
     case token_type::plus:
@@ -213,6 +214,7 @@ bool parser::parse_and_visit_statement(
   case token_type::kw_void:
   case token_type::left_paren:
   case token_type::left_square:
+  case token_type::less:
   case token_type::minus:
   case token_type::minus_minus:
   case token_type::number:

src/quick-lint-js/token.h

@@ -85,29 +85,28 @@
   QLJS_CASE_CONTEXTUAL_KEYWORD: \
   QLJS_CASE_RESERVED_KEYWORD
 
-#define QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_LESS_AND_STAR \
-  case ::quick_lint_js::token_type::ampersand:                     \
-  case ::quick_lint_js::token_type::ampersand_ampersand:           \
-  case ::quick_lint_js::token_type::bang_equal:                    \
-  case ::quick_lint_js::token_type::bang_equal_equal:              \
-  case ::quick_lint_js::token_type::circumflex:                    \
-  case ::quick_lint_js::token_type::equal_equal:                   \
-  case ::quick_lint_js::token_type::equal_equal_equal:             \
-  case ::quick_lint_js::token_type::greater:                       \
-  case ::quick_lint_js::token_type::greater_equal:                 \
-  case ::quick_lint_js::token_type::greater_greater:               \
-  case ::quick_lint_js::token_type::greater_greater_greater:       \
-  case ::quick_lint_js::token_type::less_equal:                    \
-  case ::quick_lint_js::token_type::less_less:                     \
-  case ::quick_lint_js::token_type::percent:                       \
-  case ::quick_lint_js::token_type::pipe:                          \
-  case ::quick_lint_js::token_type::pipe_pipe:                     \
-  case ::quick_lint_js::token_type::question_question:             \
+#define QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_STAR    \
+  case ::quick_lint_js::token_type::ampersand:               \
+  case ::quick_lint_js::token_type::ampersand_ampersand:     \
+  case ::quick_lint_js::token_type::bang_equal:              \
+  case ::quick_lint_js::token_type::bang_equal_equal:        \
+  case ::quick_lint_js::token_type::circumflex:              \
+  case ::quick_lint_js::token_type::equal_equal:             \
+  case ::quick_lint_js::token_type::equal_equal_equal:       \
+  case ::quick_lint_js::token_type::greater:                 \
+  case ::quick_lint_js::token_type::greater_equal:           \
+  case ::quick_lint_js::token_type::greater_greater:         \
+  case ::quick_lint_js::token_type::greater_greater_greater: \
+  case ::quick_lint_js::token_type::less_equal:              \
+  case ::quick_lint_js::token_type::less_less:               \
+  case ::quick_lint_js::token_type::percent:                 \
+  case ::quick_lint_js::token_type::pipe:                    \
+  case ::quick_lint_js::token_type::pipe_pipe:               \
+  case ::quick_lint_js::token_type::question_question:       \
   case ::quick_lint_js::token_type::star_star
 
-#define QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL                 \
-  QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_LESS_AND_STAR: \
-  case ::quick_lint_js::token_type::less:                     \
+#define QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL        \
+  QLJS_CASE_BINARY_ONLY_OPERATOR_SYMBOL_EXCEPT_STAR: \
   case ::quick_lint_js::token_type::star
 
 #define QLJS_CASE_BINARY_ONLY_OPERATOR   \