From d35a9e783920fd286cdbb1574e703f199a1415f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A1bio=20Santos?= <fabiosantosart@gmail.com>
Date: Sun, 21 Feb 2016 17:06:09 +0000
Subject: [PATCH] Importing names from places

---
 lib/ast.js               | 15 ++++++++++++++-
 lib/compress.js          |  4 ++++
 lib/output.js            |  6 ++++++
 lib/parse.js             | 24 ++++++++++++++++++------
 test/compress/harmony.js | 16 ++++++++++++++--
 5 files changed, 56 insertions(+), 9 deletions(-)

diff --git a/lib/ast.js b/lib/ast.js
index 0940647c..3457c134 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -702,10 +702,19 @@ var AST_Const = DEFNODE("Const", null, {
     $documentation: "A `const` statement"
 }, AST_Definitions);
 
-var AST_Import = DEFNODE("Import", "module_name", {
+var AST_Import = DEFNODE("Import", "imported_name module_name", {
     $documentation: "An `import` statement",
     $propdoc: {
+        imported_name: "[AST_SymbolImport] The name of the variable holding the module's default export.",
         module_name: "[AST_String] String literal describing where this module came from",
+    },
+    _walk: function(visitor) {
+        return visitor._visit(this, function() {
+            if (this.imported_name) {
+                this.imported_name._walk(visitor);
+            }
+            this.module_name._walk(visitor);
+        });
     }
 });
 
@@ -1072,6 +1081,10 @@ var AST_SymbolCatch = DEFNODE("SymbolCatch", null, {
     $documentation: "Symbol naming the exception in catch",
 }, AST_SymbolDeclaration);
 
+var AST_SymbolImport = DEFNODE("SymbolImport", null, {
+    $documentation: "Symbol refering to an imported name",
+}, AST_SymbolDeclaration);
+
 var AST_Label = DEFNODE("Label", "references", {
     $documentation: "Symbol naming a label (declaration)",
     $propdoc: {
diff --git a/lib/compress.js b/lib/compress.js
index 52fbb74d..b1fbdf25 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1775,6 +1775,10 @@ merge(Compressor.prototype, {
         return self;
     });
 
+    OPT(AST_Import, function(self, compressor) {
+        return self;
+    });
+
     OPT(AST_Function, function(self, compressor){
         self = AST_Lambda.prototype.optimize.call(self, compressor);
         if (compressor.option("unused") && !compressor.option("keep_fnames")) {
diff --git a/lib/output.js b/lib/output.js
index 4dc53798..52747603 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -1040,6 +1040,12 @@ function OutputStream(options) {
     DEFPRINT(AST_Import, function(self, output) {
         output.print("import");
         output.space();
+        if (self.imported_name) {
+            self.imported_name.print(output);
+            output.space();
+            output.print("from")
+            output.space();
+        }
         self.module_name.print(output);
         output.semicolon();
     });
diff --git a/lib/parse.js b/lib/parse.js
index 4a549fb1..4e94f589 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -1611,15 +1611,27 @@ function parse($TEXT, options) {
     }
 
     function import_() {
+        var start = prev();
+        var imported_name;
+        if (is("name")) {
+            imported_name = as_symbol(AST_SymbolImport);
+            expect_token("name", "from");
+        }
+        var mod_str = S.token;
+        if (mod_str.type !== 'string') {
+            unexpected();
+        }
+        next();
         return new AST_Import({
-            start: prev(),
+            start: start,
+            imported_name: imported_name,
             module_name: new AST_String({
-                start : S.token,
-                value : S.token.value,
-                quote : S.token.quote,
-                end   : S.token,
+                start: mod_str,
+                value: mod_str.value,
+                quote: mod_str.quote,
+                end: mod_str,
             }),
-            end: next(),
+            end: S.token,
         });
     }
 
diff --git a/test/compress/harmony.js b/test/compress/harmony.js
index 4cb3921c..dc1c2e4f 100644
--- a/test/compress/harmony.js
+++ b/test/compress/harmony.js
@@ -308,9 +308,21 @@ number_literals: {
 import_statement: {
     input: {
         import "mod-name";
-        import "module2";
+        import Foo from "bar";
+    }
+    expect_exact: "import\"mod-name\";import Foo from\"bar\";"
+}
+
+import_statement_mangling: {
+    mangle = { };
+    input: {
+        import Foo from "foo";
+        Foo();
+    }
+    expect: {
+        import a from "foo";
+        a();
     }
-    expect_exact: "import\"mod-name\";import\"module2\";"
 }
 
 // Fabio: My patches accidentally caused a crash whenever