Allow type parameter defaults in function declarations

Summary: When type parameter defaults were added (D3196321), it was not possible to supply explicit type arguments to function calls. Now that explicit type arguments to function calls are supported, it can be useful to define a polymorphic function with type parameter defaults. Reviewed By: gabelevi Differential Revision: D15679697 fbshipit-source-id: 309df3194a7e02f69ec398c56d004166d6e519e2
facebook · Jun 5, 2019 · c18ee0d · c18ee0d
1 parent dc2cfac
commit c18ee0d
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Showing 10 changed files with 98 additions and 219 deletions.
diff --git a/src/parser/object_parser.ml b/src/parser/object_parser.ml
@@ -701,7 +701,7 @@ module Object
       | true, false -> None
       | _ -> Some(Parse.identifier tmp_env)
     ) in
-    let tparams = Type.type_parameter_declaration_with_defaults env in
+    let tparams = Type.type_parameter_declaration env in
     let body, extends, implements = _class env in
     Ast.Statement.ClassDeclaration { Class.
       id;
@@ -724,7 +724,7 @@ module Object
       | T_LCURLY -> None, None
       | _ ->
           let id = Some (Parse.identifier env) in
-          let tparams = Type.type_parameter_declaration_with_defaults env in
+          let tparams = Type.type_parameter_declaration env in
           id, tparams in
     let body, extends, implements = _class env in
     Ast.Expression.Class { Class.

diff --git a/src/parser/statement_parser.ml b/src/parser/statement_parser.ml
@@ -540,7 +540,7 @@ module Statement
     Expect.token env T_TYPE;
     Eat.push_lex_mode env Lex_mode.TYPE;
     let id = Type.type_identifier env in
-    let tparams = Type.type_parameter_declaration_with_defaults env in
+    let tparams = Type.type_parameter_declaration env in
     Expect.token env T_ASSIGN;
     let right = Type._type env in
     Eat.semicolon env;
@@ -572,7 +572,7 @@ module Statement
     Expect.token env T_TYPE;
     Eat.push_lex_mode env Lex_mode.TYPE;
     let id = Type.type_identifier env in
-    let tparams = Type.type_parameter_declaration_with_defaults env in
+    let tparams = Type.type_parameter_declaration env in
     let supertype = match Peek.token env with
     | T_COLON ->
         Expect.token env T_COLON;
@@ -610,7 +610,7 @@ module Statement
     then error env Error.UnexpectedTypeInterface;
     Expect.token env T_INTERFACE;
     let id = Type.type_identifier env in
-    let tparams = Type.type_parameter_declaration_with_defaults env in
+    let tparams = Type.type_parameter_declaration env in
     let { Ast.Type.Interface.extends; body } = Type.interface_helper env in
     Statement.Interface.({
       id;
@@ -649,7 +649,7 @@ module Statement
       let env = env |> with_strict true in
       Expect.token env T_CLASS;
       let id = Parse.identifier env in
-      let tparams = Type.type_parameter_declaration_with_defaults env in
+      let tparams = Type.type_parameter_declaration env in
       let extends = if Expect.maybe env T_EXTENDS then Some (Type.generic env) else None in
       let mixins = match Peek.token env with
       | T_IDENTIFIER { raw = "mixins"; _ } -> Eat.token env; mixins env []

diff --git a/src/parser/test/flow/types/parameter_defaults/migrated_0026.tree.json b/src/parser/test/flow/types/parameter_defaults/migrated_0026.tree.json
@@ -1,14 +1,4 @@
 {
-  "errors":[
-    {
-      "loc":{"source":null,"start":{"line":1,"column":15},"end":{"line":1,"column":16}},
-      "message":"Unexpected token ="
-    },
-    {
-      "loc":{"source":null,"start":{"line":1,"column":17},"end":{"line":1,"column":23}},
-      "message":"Unexpected reserved type"
-    }
-  ],
   "type":"Program",
   "loc":{"source":null,"start":{"line":1,"column":0},"end":{"line":1,"column":29}},
   "range":[0,29],
@@ -44,21 +34,16 @@
         "params":[
           {
             "type":"TypeParameter",
-            "loc":{"source":null,"start":{"line":1,"column":13},"end":{"line":1,"column":14}},
-            "range":[13,14],
+            "loc":{"source":null,"start":{"line":1,"column":13},"end":{"line":1,"column":23}},
+            "range":[13,23],
             "name":"T",
             "bound":null,
             "variance":null,
-            "default":null
-          },
-          {
-            "type":"TypeParameter",
-            "loc":{"source":null,"start":{"line":1,"column":17},"end":{"line":1,"column":23}},
-            "range":[17,23],
-            "name":"string",
-            "bound":null,
-            "variance":null,
-            "default":null
+            "default":{
+              "type":"StringTypeAnnotation",
+              "loc":{"source":null,"start":{"line":1,"column":17},"end":{"line":1,"column":23}},
+              "range":[17,23]
+            }
           }
         ]
       }

diff --git a/src/parser/test/flow/types/parameter_defaults/migrated_0027.tree.json b/src/parser/test/flow/types/parameter_defaults/migrated_0027.tree.json
@@ -1,13 +1,5 @@
 {
   "errors":[
-    {
-      "loc":{"source":null,"start":{"line":1,"column":23},"end":{"line":1,"column":24}},
-      "message":"Unexpected token ="
-    },
-    {
-      "loc":{"source":null,"start":{"line":1,"column":25},"end":{"line":1,"column":31}},
-      "message":"Unexpected reserved type"
-    },
     {
       "loc":{"source":null,"start":{"line":1,"column":35},"end":{"line":1,"column":36}},
       "message":"Unexpected token {"
@@ -56,21 +48,16 @@
               "params":[
                 {
                   "type":"TypeParameter",
-                  "loc":{"source":null,"start":{"line":1,"column":21},"end":{"line":1,"column":22}},
-                  "range":[21,22],
+                  "loc":{"source":null,"start":{"line":1,"column":21},"end":{"line":1,"column":31}},
+                  "range":[21,31],
                   "name":"T",
                   "bound":null,
                   "variance":null,
-                  "default":null
-                },
-                {
-                  "type":"TypeParameter",
-                  "loc":{"source":null,"start":{"line":1,"column":25},"end":{"line":1,"column":31}},
-                  "range":[25,31],
-                  "name":"string",
-                  "bound":null,
-                  "variance":null,
-                  "default":null
+                  "default":{
+                    "type":"StringTypeAnnotation",
+                    "loc":{"source":null,"start":{"line":1,"column":25},"end":{"line":1,"column":31}},
+                    "range":[25,31]
+                  }
                 }
               ]
             }

diff --git a/src/parser/test/flow/types/parameter_defaults/migrated_0028.tree.json b/src/parser/test/flow/types/parameter_defaults/migrated_0028.tree.json
@@ -1,14 +1,4 @@
 {
-  "errors":[
-    {
-      "loc":{"source":null,"start":{"line":1,"column":9},"end":{"line":1,"column":10}},
-      "message":"Unexpected token ="
-    },
-    {
-      "loc":{"source":null,"start":{"line":1,"column":11},"end":{"line":1,"column":17}},
-      "message":"Unexpected reserved type"
-    }
-  ],
   "type":"Program",
   "loc":{"source":null,"start":{"line":1,"column":0},"end":{"line":1,"column":26}},
   "range":[0,26],
@@ -58,21 +48,16 @@
                 "params":[
                   {
                     "type":"TypeParameter",
-                    "loc":{"source":null,"start":{"line":1,"column":7},"end":{"line":1,"column":8}},
-                    "range":[7,8],
+                    "loc":{"source":null,"start":{"line":1,"column":7},"end":{"line":1,"column":17}},
+                    "range":[7,17],
                     "name":"T",
                     "bound":null,
                     "variance":null,
-                    "default":null
-                  },
-                  {
-                    "type":"TypeParameter",
-                    "loc":{"source":null,"start":{"line":1,"column":11},"end":{"line":1,"column":17}},
-                    "range":[11,17],
-                    "name":"string",
-                    "bound":null,
-                    "variance":null,
-                    "default":null
+                    "default":{
+                      "type":"StringTypeAnnotation",
+                      "loc":{"source":null,"start":{"line":1,"column":11},"end":{"line":1,"column":17}},
+                      "range":[11,17]
+                    }
                   }
                 ]
               }

diff --git a/src/parser/test/flow/types/parameter_defaults/migrated_0029.tree.json b/src/parser/test/flow/types/parameter_defaults/migrated_0029.tree.json
@@ -1,14 +1,4 @@
 {
-  "errors":[
-    {
-      "loc":{"source":null,"start":{"line":1,"column":16},"end":{"line":1,"column":17}},
-      "message":"Unexpected token ="
-    },
-    {
-      "loc":{"source":null,"start":{"line":1,"column":18},"end":{"line":1,"column":24}},
-      "message":"Unexpected reserved type"
-    }
-  ],
   "type":"Program",
   "loc":{"source":null,"start":{"line":1,"column":0},"end":{"line":1,"column":32}},
   "range":[0,32],
@@ -66,21 +56,16 @@
                 "params":[
                   {
                     "type":"TypeParameter",
-                    "loc":{"source":null,"start":{"line":1,"column":14},"end":{"line":1,"column":15}},
-                    "range":[14,15],
+                    "loc":{"source":null,"start":{"line":1,"column":14},"end":{"line":1,"column":24}},
+                    "range":[14,24],
                     "name":"T",
                     "bound":null,
                     "variance":null,
-                    "default":null
-                  },
-                  {
-                    "type":"TypeParameter",
-                    "loc":{"source":null,"start":{"line":1,"column":18},"end":{"line":1,"column":24}},
-                    "range":[18,24],
-                    "name":"string",
-                    "bound":null,
-                    "variance":null,
-                    "default":null
+                    "default":{
+                      "type":"StringTypeAnnotation",
+                      "loc":{"source":null,"start":{"line":1,"column":18},"end":{"line":1,"column":24}},
+                      "range":[18,24]
+                    }
                   }
                 ]
               }
@@ -92,8 +77,8 @@
           }
         ]
       },
-      "superClass":null,
       "typeParameters":null,
+      "superClass":null,
       "superTypeParameters":null,
       "implements":[],
       "decorators":[]

diff --git a/src/parser/test/flow/types/parameter_defaults/migrated_0030.tree.json b/src/parser/test/flow/types/parameter_defaults/migrated_0030.tree.json
@@ -1,14 +1,4 @@
 {
-  "errors":[
-    {
-      "loc":{"source":null,"start":{"line":1,"column":17},"end":{"line":1,"column":18}},
-      "message":"Unexpected token ="
-    },
-    {
-      "loc":{"source":null,"start":{"line":1,"column":19},"end":{"line":1,"column":25}},
-      "message":"Unexpected reserved type"
-    }
-  ],
   "type":"Program",
   "loc":{"source":null,"start":{"line":1,"column":0},"end":{"line":1,"column":34}},
   "range":[0,34],
@@ -70,21 +60,16 @@
                   "params":[
                     {
                       "type":"TypeParameter",
-                      "loc":{"source":null,"start":{"line":1,"column":15},"end":{"line":1,"column":16}},
-                      "range":[15,16],
+                      "loc":{"source":null,"start":{"line":1,"column":15},"end":{"line":1,"column":25}},
+                      "range":[15,25],
                       "name":"T",
                       "bound":null,
                       "variance":null,
-                      "default":null
-                    },
-                    {
-                      "type":"TypeParameter",
-                      "loc":{"source":null,"start":{"line":1,"column":19},"end":{"line":1,"column":25}},
-                      "range":[19,25],
-                      "name":"string",
-                      "bound":null,
-                      "variance":null,
-                      "default":null
+                      "default":{
+                        "type":"StringTypeAnnotation",
+                        "loc":{"source":null,"start":{"line":1,"column":19},"end":{"line":1,"column":25}},
+                        "range":[19,25]
+                      }
                     }
                   ]
                 }
@@ -96,8 +81,8 @@
             }
           ]
         },
-        "superClass":null,
         "typeParameters":null,
+        "superClass":null,
         "superTypeParameters":null,
         "implements":[],
         "decorators":[]

diff --git a/src/parser/test/flow/types/parameter_defaults/migrated_0031.tree.json b/src/parser/test/flow/types/parameter_defaults/migrated_0031.tree.json
@@ -1,14 +1,4 @@
 {
-  "errors":[
-    {
-      "loc":{"source":null,"start":{"line":1,"column":24},"end":{"line":1,"column":25}},
-      "message":"Unexpected token ="
-    },
-    {
-      "loc":{"source":null,"start":{"line":1,"column":26},"end":{"line":1,"column":32}},
-      "message":"Unexpected reserved type"
-    }
-  ],
   "type":"Program",
   "loc":{"source":null,"start":{"line":1,"column":0},"end":{"line":1,"column":43}},
   "range":[0,43],
@@ -62,21 +52,16 @@
                 "params":[
                   {
                     "type":"TypeParameter",
-                    "loc":{"source":null,"start":{"line":1,"column":22},"end":{"line":1,"column":23}},
-                    "range":[22,23],
+                    "loc":{"source":null,"start":{"line":1,"column":22},"end":{"line":1,"column":32}},
+                    "range":[22,32],
                     "name":"T",
                     "bound":null,
                     "variance":null,
-                    "default":null
-                  },
-                  {
-                    "type":"TypeParameter",
-                    "loc":{"source":null,"start":{"line":1,"column":26},"end":{"line":1,"column":32}},
-                    "range":[26,32],
-                    "name":"string",
-                    "bound":null,
-                    "variance":null,
-                    "default":null
+                    "default":{
+                      "type":"StringTypeAnnotation",
+                      "loc":{"source":null,"start":{"line":1,"column":26},"end":{"line":1,"column":32}},
+                      "range":[26,32]
+                    }
                   }
                 ]
               }