Implements the import keywords "once" and "multiple". #28

Author: Horcrux7

src/com/inet/lib/less/LessLookAheadReader.java

@@ -40,7 +40,7 @@ class LessLookAheadReader extends LessObject implements Closeable {
 
     private final StringBuilder cache = new StringBuilder();
 
-    private final boolean       isReference;
+    private final boolean       isReference, isMultiple;
 
     private int                 cachePos;
 
@@ -49,11 +49,13 @@ class LessLookAheadReader extends LessObject implements Closeable {
      * @param reader the underlying reader
      * @param fileName the filename of the less file or null if a String is parsed.
      * @param isReference true, if the less file is imported as reference
+     * @param isMultiple true, if the less file is imported with keyword "multiple"
      */
-    LessLookAheadReader( Reader reader, String fileName, boolean isReference ) {
+    LessLookAheadReader( Reader reader, String fileName, boolean isReference, boolean isMultiple ) {
         super( fileName );
         this.reader = reader.markSupported() ? reader : new BufferedReader( reader );
         this.isReference = isReference;
+        this.isMultiple = isMultiple;
         line = 1;
         column = 0;
     }
@@ -328,4 +330,13 @@ public void close() throws IOException {
     boolean isReference() {
         return isReference;
     }
+
+
+    /**
+     * If the less file of this reader was import with "multiple" keyword.
+     * @return true, if multiple
+     */
+    boolean isMultiple() {
+        return isMultiple;
+    }
 }

src/com/inet/lib/less/LessParser.java

@@ -32,6 +32,7 @@
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.StringTokenizer;
 
@@ -65,6 +66,8 @@ class LessParser implements FormattableContainer {
 
     private ArrayDeque<Rule>            ruleStack     = new ArrayDeque<>();
 
+    private HashSet<URL>                imports       = new HashSet<>();
+
     private List<LazyImport>            lazyImports;
 
     /**
@@ -101,7 +104,7 @@ void parse( URL baseURL, Reader input, ReaderFactory readerFactory  ) throws Mal
         this.baseURL = baseURL;
         this.readerFactory = readerFactory;
         this.relativeURL = new URL( "file", null, "" );
-        this.reader = new LessLookAheadReader( input, null, false );
+        this.reader = new LessLookAheadReader( input, null, false, false );
         parse( this );
     }
 
@@ -430,6 +433,7 @@ private void importFile( FormattableContainer currentRule, final String name ) {
         boolean isReference = reader.isReference();
         boolean isCss = false;
         boolean isLess = false;
+        boolean isMultiple = reader.isMultiple();
         if( filename.startsWith( "(" ) ) {
             int endIdx = filename.indexOf( ')', 1);
             if( endIdx > 0 ) {
@@ -439,11 +443,15 @@ private void importFile( FormattableContainer currentRule, final String name ) {
                     String keywordStr = tokenizer.nextToken().trim();
                     switch( keywordStr ) {
                         case "inline":
-                        case "once":
-                        case "multiple":
                         case "optional":
                             System.err.println( "not implemented @import keyword: " + keywordStr ); //TODO
                             break;
+                        case "once":
+                            isMultiple = false;
+                            break;
+                        case "multiple":
+                            isMultiple = true;
+                            break;
                         case "less":
                             isLess = true;
                             isCss = false;
@@ -542,12 +550,14 @@ private void importFile( FormattableContainer currentRule, final String name ) {
                 baseURL = baseURL == null ? new URL( filename ) : new URL( baseURL, filename );
             }
             relativeURL = new URL( relativeURL, filename );
-            if( isReference != reader.isReference() ) {
-                add( new ReferenceInfo( isReference ) );
+            if( imports.add( baseURL ) || isMultiple ) {
+                if( isReference != reader.isReference() ) {
+                    add( new ReferenceInfo( isReference ) );
+                }
+                reader = new LessLookAheadReader( readerFactory.create( baseURL ), filename, isReference, isMultiple );
+                parse( currentRule );
+                reader.close();
             }
-            reader = new LessLookAheadReader( readerFactory.create( baseURL ), filename, isReference );
-            parse( currentRule );
-            reader.close();
         } catch( LessException ex ) {
             throw ex;
         } catch( Exception ex ) {

test/com/inet/lib/less/samples/less_org_tests/less/import-once.css

@@ -0,0 +1,15 @@
+#import {
+  color: red;
+}
+body {
+  width: 100%;
+}
+.test-f {
+  height: 10px;
+}
+body {
+  width: 100%;
+}
+.test-f {
+  height: 10px;
+}

test/com/inet/lib/less/samples/less_org_tests/less/import-once.less

@@ -0,0 +1,6 @@
+@import "import/import-once-test-c";
+@import "import/import-once-test-c";
+@import "import/import-once-test-c.less";
+@import "import/deeper/import-once-test-a";
+@import (multiple) "import/import-test-f.less";
+@import (multiple) "import/import-test-f.less";