Add Toml#read(Toml)

Fixes #32

CHANGELOG.md

@@ -1,5 +1,11 @@
 # toml4j Changelog
 
+## 0.7.0 / 2016-07-12
+
+## Added
+
+* Toml#read(Toml) merges two Toml instances (thanks to __[gustavkarlsson](https://github.com/gustavkarlsson)__)
+
 ## 0.6.0 / 2016-06-14
 
 ## Added

README.md

@@ -31,7 +31,7 @@ MyClass myClass = toml.to(MyClass.class);
 
 ## Usage
 
-A `com.moandjiezana.toml.Toml` instance is populated by calling one of `read(File)`, `read(InputStream)`, `read(Reader)` or `read(String)`.
+A `com.moandjiezana.toml.Toml` instance is populated by calling one of `read(File)`, `read(InputStream)`, `read(Reader)`, `read(String)` or `read(Toml)`.
 
 ```java
 Toml toml = new Toml().read("a=1");
@@ -176,6 +176,15 @@ String network3Operator2Location = toml.getString("networks[2].operators[1].loca
 
 The constructor can be given a set of default values that will be used as fallbacks. For tables and table arrays, a shallow merge is performed.
 
+`Toml#read(Toml)` is used to merge two Toml instances:
+
+```java
+Toml toml1 = new Toml().read("a=1");
+Toml toml2 = new Toml().read(getTomlFile());
+
+Toml mergedToml = new Toml(toml1).read(toml2);
+```
+
 You can also call an overloaded version of the getters that take a default value. Note that the default value provided in the constructor take precedence over the one provided by the getter.
 
 ```toml

src/main/java/com/moandjiezana/toml/Toml.java

@@ -54,7 +54,7 @@ public class Toml {
   }
 
   /**
-   * @param defaults fallback values used when the requested key or table is not present.
+   * @param defaults fallback values used when the requested key or table is not present in the TOML source that has been read.
    */
   public Toml(Toml defaults) {
     this(defaults, new HashMap<String, Object>());
@@ -115,6 +115,18 @@ public class Toml {
     return this;
   }
 
+  /**
+   * Populates the current Toml instance with values from otherToml.
+   *
+   * @param otherToml 
+   * @return this instance
+   */
+  public Toml read(Toml otherToml) {
+    this.values = otherToml.values;
+    
+    return this;
+  }
+
   /**
    * Populates the current Toml instance with values from tomlString.
    *

src/test/java/com/moandjiezana/toml/TomlReadTest.java

@@ -59,4 +59,24 @@ public class TomlReadTest {
       assertThat(e.getCause(), instanceOf(IOException.class));
     }
   }
+
+  @Test
+  public void should_read_toml_without_defaults() {
+    Toml toml1 = new Toml().read("a = 1");
+    Toml toml2 = new Toml().read(toml1);
+
+    assertEquals(toml1.getLong("a"), toml2.getLong("a"));
+  }
+
+  @Test
+  public void should_read_toml_and_merge_with_defaults() {
+    Toml toml1 = new Toml().read("a = 1\nc = 3\nd = 5");
+    Toml toml2 = new Toml().read("b = 2\nc = 4");
+    Toml mergedToml = new Toml(toml1).read(toml2);
+
+    assertEquals(toml1.getLong("a"), mergedToml.getLong("a"));
+    assertEquals(toml2.getLong("b"), mergedToml.getLong("b"));
+    assertEquals(toml2.getLong("c"), mergedToml.getLong("c"));
+    assertEquals(toml1.getLong("d"), mergedToml.getLong("d"));
+  }
 }