Merge branch 'develop' of github.com:rdfhdt/hdt-cpp into develop

Author: LaurensRietveld

README.md

@@ -41,17 +41,28 @@ Then, run:
 After building, these are the typical operations that you will perform:
 
 - Convert your RDF data to HDT:
-
+    
+    NB: the input stream is assumed to be valid RDF, so you should validate your data before feeding it into rdf2hdt.
+    
+    ```
     $ tools/rdf2hdt data/test.nt data/test.hdt
+    ```
+
+- Create only the index of an HDT file:
 
-NB: the input stream is assumed to be valid RDF, so you should validate your data before feeding it into rdf2hdt.
+    ```
+    $ tools/hdtSearch -q 0 data/test.hdt
+    ```
 
 - Convert an HDT to another RDF serialization format, such as N-Triples:
 
+    ```
     $ tools/hdt2rdf data/test.hdt data/test.hdtexport.nt
+    ```
 
 - Open a terminal to search triple patterns within an HDT file:
 
+    ```
     $ tools/hdtSearch data/test.hdt
     >> ? ? ?
     http://example.org/uri3 http://example.org/predicate3 http://example.org/uri4
@@ -72,14 +83,19 @@ NB: the input stream is assumed to be valid RDF, so you should validate your dat
     2 results shown.
 
     >> exit
+    ```
 
 - Extract the Header of an HDT file:
 
+    ```
     $ tools/hdtInfo data/test.hdt > header.nt
+    ```
 
 - Replace the Header of an HDT file with a new one. For example, by editing the existing one as extracted using `hdtInfo`:
 
+    ```
     $ tools/replaceHeader data/test.hdt data/testOutput.hdt newHeader.nt
+    ```
 
 ## Contributing
 

libhdt/tools/rdf2hdt.cpp

@@ -164,8 +164,21 @@ int main(int argc, char **argv) {
         if (dot_position != string::npos)
             // Extract extension from file name
             rdfFormat = inputFile.substr (dot_position + 1, string::npos);
+        
+        /**
+         * If rdfFormat is still "", it means -f was not specified and the file
+         * didn't have any extension. The default format is defined at the top
+         * of this file: RDFNotation notation = NTRIPLES;
+         */
+        if (rdfFormat == "")
+        {
+            rdfFormat = "nt";
+            vout << "No input format detected. Using default: NTRIPLES." << endl;
+        }
     }
-
+    
+    // ASSERT: here rdfFormat must be != ""
+    
     // Lower-case rdfFormat
     transform (rdfFormat.begin (), rdfFormat.end (), rdfFormat.begin (), ::tolower);
 
@@ -180,15 +193,6 @@ int main(int argc, char **argv) {
         notation = TURTLE;
     else if (rdfFormat == "rdfxml" || rdfFormat == "xml")
         notation = XML;
-    
-    /**
-     * If rdfFormat is still "", it means -f was not specified and the file
-     * didn't have any extension. The default format is defined at the top
-     * of this file: RDFNotation notation = NTRIPLES;
-     */
-    else if (rdfFormat == "")
-        vout << "No input format detected. Using default: NTRIPLES." << endl;
-    
     // -f or file extension detected, but didn't match any valid format.
     else {
         cerr << "ERROR: Detected \"" << rdfFormat << "\" input format. Must be one of:" << endl