refactor `Compressor.toplevel` (#2149)

diff --git a/lib/compress.js b/lib/compress.js
index 8890759..c24510f 100644 (file)
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -124,13 +124,13 @@ function Compressor(options, false_by_default) {
         };
     }
     var toplevel = this.options["toplevel"];
-    if (typeof toplevel == "string") {
-        this.toplevel.funcs = /funcs/.test(toplevel);
-        this.toplevel.vars = /vars/.test(toplevel);
-    } else {
-        this.toplevel = toplevel ? return_true : return_false;
-        this.toplevel.funcs = this.toplevel.vars = toplevel;
-    }
+    this.toplevel = typeof toplevel == "string" ? {
+        funcs: /funcs/.test(toplevel),
+        vars: /vars/.test(toplevel)
+    } : {
+        funcs: toplevel,
+        vars: toplevel
+    };
     var sequences = this.options["sequences"];
     this.sequences_limit = sequences == 1 ? 800 : sequences | 0;
     this.warnings_produced = {};
@@ -139,11 +139,11 @@ function Compressor(options, false_by_default) {
 Compressor.prototype = new TreeTransformer;
 merge(Compressor.prototype, {
     option: function(key) { return this.options[key] },
-    toplevel: function(def) {
-        for (var i = 0, len = def.orig.length; i < len; i++)
+    exposed: function(def) {
+        if (def.global) for (var i = 0, len = def.orig.length; i < len; i++)
             if (!this.toplevel[def.orig[i] instanceof AST_SymbolDefun ? "funcs" : "vars"])
-                return false;
-        return true;
+                return true;
+        return false;
     },
     compress: function(node) {
         if (this.option("expression")) {
@@ -345,7 +345,7 @@ merge(Compressor.prototype, {
                 }
                 if (node instanceof AST_Defun) {
                     var d = node.name.definition();
-                    if (d.global && !compressor.toplevel(d) || safe_to_read(d)) {
+                    if (compressor.exposed(d) || safe_to_read(d)) {
                         d.fixed = false;
                     } else {
                         d.fixed = node;
@@ -517,7 +517,7 @@ merge(Compressor.prototype, {
             def.escaped = false;
             if (def.scope.uses_eval) {
                 def.fixed = false;
-            } else if (!def.global || compressor.toplevel(def)) {
+            } else if (!compressor.exposed(def)) {
                 def.fixed = undefined;
             } else {
                 def.fixed = false;
@@ -748,7 +748,7 @@ merge(Compressor.prototype, {
                             }
                             if (candidate instanceof AST_VarDef) {
                                 var def = candidate.name.definition();
-                                if (def.references.length == 1 && (!def.global || compressor.toplevel(def))) {
+                                if (def.references.length == 1 && !compressor.exposed(def)) {
                                     return maintain_this_binding(parent, node, candidate.value);
                                 }
                                 return make_node(AST_Assign, candidate, {
@@ -810,7 +810,7 @@ merge(Compressor.prototype, {
                 if (expr instanceof AST_VarDef) {
                     var def = expr.name.definition();
                     if (def.orig.length > 1
-                        || def.references.length == 1 && (!def.global || compressor.toplevel(def))) {
+                        || def.references.length == 1 && !compressor.exposed(def)) {
                         return make_node(AST_SymbolRef, expr.name, expr.name);
                     }
                 } else {
@@ -3918,7 +3918,7 @@ merge(Compressor.prototype, {
                         }
                         var name_length = d.name.length;
                         var overhead = 0;
-                        if (compressor.option("unused") && (!d.global || compressor.toplevel(d))) {
+                        if (compressor.option("unused") && !compressor.exposed(d)) {
                             overhead = (name_length + 2 + value_length) / d.references.length;
                         }
                         d.should_replace = value_length <= name_length + overhead ? fn : false;