[ES6] Implemented parse for export Name from Module variants. (#1701)

- add `AST_Export` new variants output
- add tests to `test/compress/`
- update `$propdoc` of `AST_Export` ("exported_names" & "module_name")
- add tests for `export ...  as ...` variants

lib/ast.js

@@ -789,11 +789,13 @@ var AST_Import = DEFNODE("Import", "imported_name imported_names module_name", {
     }
 });
 
-var AST_Export = DEFNODE("Export", "exported_definition exported_value is_default", {
+var AST_Export = DEFNODE("Export", "exported_definition exported_value is_default exported_names module_name", {
     $documentation: "An `export` statement",
     $propdoc: {
         exported_definition: "[AST_Defun|AST_Definitions|AST_DefClass?] An exported definition",
         exported_value: "[AST_Node?] An exported value",
+        exported_names: "[AST_NameImport*?] List of exported names",
+        module_name: "[AST_String?] Name of the file to load exports from",
         is_default: "[Boolean] Whether this is the default exported value of this module"
     },
     _walk: function (visitor) {

lib/output.js

@@ -1277,11 +1277,37 @@ function OutputStream(options) {
             output.print("default");
             output.space();
         }
-        if (self.exported_value) {
+        if (self.exported_names) {
+            output.space();
+
+            if (self.exported_names.length === 1 && self.exported_names[0].name.name === "*") {
+                self.exported_names[0].print(output);
+            } else {
+                output.print("{");
+                self.exported_names.forEach(function (name_import, i) {
+                    output.space();
+                    name_import.print(output);
+                    if (i < self.exported_names.length - 1) {
+                        output.print(",");
+                        output.space();
+                    }
+                });
+                output.space();
+                output.print("}");
+            }
+            output.space();
+        }
+        else if (self.exported_value) {
             self.exported_value.print(output);
         } else if (self.exported_definition) {
             self.exported_definition.print(output);
         }
+        if (self.module_name) {
+            output.space();
+            output.print("from");
+            output.space();
+            self.module_name.print(output);
+        }
         output.semicolon();
     });
 

lib/parse.js

@@ -2237,17 +2237,85 @@ function parse($TEXT, options) {
         })
     }
 
+    function import_nameAsterisk() {
+        var start = S.token;
+        var foreign_name;
+        var name;
+
+        next();
+
+        var end = prev();
+
+        name = new AST_SymbolImport({
+            name: '*',
+            start: start,
+            end: end,
+        });
+
+        foreign_name = new AST_SymbolImportForeign({
+            name: '*',
+            start: start,
+            end: end,
+        });
+
+        return new AST_NameImport({
+            start: start,
+            foreign_name: foreign_name,
+            name: name,
+            end: end,
+        })
+    }
+
     function export_() {
         var start = S.token;
         var is_default;
         var exported_value;
         var exported_definition;
+        var exported_names;
 
         if (is("keyword", "default")) {
             is_default = true;
             next();
         }
 
+        if (is("punc", "{")) {
+            next();
+            exported_names = [];
+            while (!is("punc", "}")) {
+                exported_names.push(import_name());
+                if (is("punc", ",")) {
+                    next();
+                }
+            }
+            next();
+        } else if (is("operator", "*")) {
+            var st = prev();
+            exported_names = [import_nameAsterisk()];
+        }
+
+        if (exported_names) {
+            expect_token("name", "from");
+
+            var mod_str = S.token;
+            if (mod_str.type !== 'string') {
+                unexpected();
+            }
+            next();
+
+            return new AST_Export({
+                start: start,
+                is_default: is_default,
+                exported_names: exported_names,
+                module_name: new AST_String({
+                    start: mod_str,
+                    value: mod_str.value,
+                    quote: mod_str.quote,
+                    end: mod_str,
+                }),
+                end: prev(),
+            });
+        }
+
         var is_definition =
             is("keyword", "var") || is("keyword", "let") || is("keyword", "const") ||
             is("keyword", "class") || is("keyword", "function");