Closes #260

corpus/expressions.txt

@@ -1065,6 +1065,8 @@ object O {
   }
   { b =>
    if (c) d.e }
+  { a => implicit b => b }
+  { (a: Int) ?=> (b: Int) => b }
 }
 
 --------------------------------------------------------------------------------
@@ -1137,7 +1139,25 @@ object O {
                 (identifier))
               (field_expression
                 (identifier)
-                (identifier)))))))))
+                (identifier))))))
+      (block
+        (lambda_expression
+          (identifier)
+          (lambda_expression
+            (identifier)
+            (identifier))))
+      (block
+        (lambda_expression
+          (bindings
+            (binding
+              (identifier)
+              (type_identifier)))
+          (lambda_expression
+            (bindings
+              (binding
+                (identifier)
+                (type_identifier)))
+            (identifier)))))))
 
 ================================================================================
 Unit expressions

grammar.js

@@ -90,6 +90,7 @@ module.exports = grammar({
     [$.class_parameters],
     // 'for'  operator_identifier  ':'  _annotated_type  •  ':'  …
     [$._type, $.compound_type],
+    [$.lambda_expression, $.modifiers],
   ],
 
   word: $ => $._alpha_identifier,
@@ -1051,8 +1052,15 @@ module.exports = grammar({
     lambda_expression: $ =>
       prec.right(
         seq(
-          field("parameters", choice($.bindings, $._identifier, $.wildcard)),
-          "=>",
+          field(
+            "parameters",
+            choice(
+              $.bindings,
+              seq(optional("implicit"), $._identifier),
+              $.wildcard,
+            ),
+          ),
+          choice("=>", "?=>"),
           $._indentable_expression,
         ),
       ),

script/smoke_test.sh

@@ -3,7 +3,7 @@
 # This is an integration test to generally check the quality of parsing.
 
 SCALA_SCALA_LIBRARY_EXPECTED=100
-SCALA_SCALA_COMPILER_EXPECTED=95
+SCALA_SCALA_COMPILER_EXPECTED=96
 DOTTY_COMPILER_EXPECTED=83
 SYNTAX_COMPLEXITY_CEILING=1300