fix: java import

* inline unnecessary second call
* add short-circuit

Author: caiuswang

.grit/patterns/java/_test_java_imports.md

@@ -8,7 +8,7 @@ tag: [java]
 ```grit
 language java
 file($body) where {
-    $delete_import = "import a.b.Text;",
+    $delete_import = `import a.b.Text;`,
     $body<: maybe contains remove_import_statement($delete_import)
 }
 ```
@@ -90,7 +90,7 @@ public class AClass {
 ```grit
 language java
 file($body) where {
-    $new_import = "import a.b.Text;",
+    $new_import = `import a.b.Text;`,
     $body<: maybe contains ensure_import_statement($new_import)
 }
 ```
@@ -171,7 +171,7 @@ public class AClass {
 
 ```grit
 language java
-replace_import_statement("import a.b.Text;", "import a.c.Text;")
+replace_import_statement(`import a.b.Text;`, `import a.c.Text;`)
 ```
 
 ## test `replace_import_statement` when have

.grit/patterns/java/java.grit

@@ -4,7 +4,9 @@ language java
 private pattern before_each_file_stdlib() { 
   file($body) where {
      $body <: init_vars(),
-     $body <: init_import()
+     $body <: maybe contains bubble import_declaration() as $this_import where {
+         $GLOBAL_EXIST_IMPORTS += $this_import,
+     }
   }
 }
 
@@ -26,7 +28,6 @@ private pattern after_rewrite() {
   }
 }
 
-
 private pattern init_vars() {
     $_ where {
         $GLOBAL_EXIST_IMPORTS = [],
@@ -36,60 +37,47 @@ private pattern init_vars() {
     }
 }
 
-private pattern init_import() {
-    $_ where {
-       $program <: accumulate_all_imports(),
-    }
-}
-
-private pattern accumulate_all_imports() {
-    $_ where {
-        $program <: maybe contains bubble() import_declaration() as $this_import where {
-            $GLOBAL_EXIST_IMPORTS += text(`$this_import`),
-        },
-    }
-}
 
 private pattern process_all_import() {
     $body where {
+            // short-circuit if no changes
+            or {
+                $GLOBAL_NEW_FROM_IMPORTS <: not [],
+                $GLOBAL_REMOVE_IMPORTS <: not [],
+                $GLOBAL_REMOVE_DUPLICATE_EXIST_IMPORTS <: true,
+            },
             $last_import = "",
             $exists_imports = [],
+            $body <: contains package_declaration() as $pkg_decl,
+            // no existing imports, just add all new imports
+            $all_import = join(distinct($GLOBAL_NEW_FROM_IMPORTS), `\n`),
             if ($body <: not contains bubble() import_declaration()) {
-                $body <: contains bubble() package_declaration() as $pkg_decl where {
-                    $all_import = join(distinct($GLOBAL_NEW_FROM_IMPORTS), `\n`),
-                    if ($all_import <: not ``) {
-                        $pkg_decl => `$pkg_decl\n\n$all_import`
-                    }
+                if ($all_import <: not ``) {
+                    $pkg_decl => `$pkg_decl\n\n$all_import`
                 }
             }
             else {
-                $body <: contains  bubble($last_import, $exists_imports) import_declaration() as $bef where {
-                    $last_import = $bef,
-                    if ($exists_imports <: some $bef) {
+                $body <: contains bubble($last_import, $exists_imports) import_declaration() as $this_import where {
+                    $last_import = $this_import,
+                    if ($exists_imports <: some $this_import) {
                         // duplicate import, remove it
                         if ($GLOBAL_REMOVE_DUPLICATE_EXIST_IMPORTS <: true ) {
-                            $bef => .
+                            $this_import => .
                         }
                     } else {
-                        if ($GLOBAL_REMOVE_IMPORTS <: some $bef) {
-                            $bef => .
+                        if ($GLOBAL_REMOVE_IMPORTS <: some $this_import) {
+                            $this_import => .
                         }, 
-                        $exists_imports += text($bef)
+                        $exists_imports += text($this_import)
                     }
                 },
-                $all_import = join(distinct($GLOBAL_NEW_FROM_IMPORTS), `\n`),
                 // last_import need to be deleted if in remove imports
                 if ($GLOBAL_REMOVE_IMPORTS <: some $last_import) {
                     $last_import => `$all_import`
                 } else if ($last_import <: not ""){
                     if ($all_import <: not ``) {
                         $last_import => `$last_import\n$all_import`
                     }
-                } else {
-                    $body <: contains bubble($last_import) package_declaration() as $pkg_decl,
-                    if ($all_import <: not ``) {
-                        $pkg_decl => `$pkg_decl\n$all_import`
-                    }
                 }
             }
     }