Add a way to control spacing around array brackets.

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

@@ -14,7 +14,11 @@ class PrimitiveArrayValueWriter extends ArrayValueWriter {
   public void write(Object value, WriterContext context) {
     Collection values = normalize(value);
 
-    context.output.append("[ ");
+    context.output.append('[');
+    if (context.getTomlWriter().wantSpaceyArrays()) {
+      context.output.append(' ');
+    }
+
     boolean first = true;
     for (Object elem : values) {
       if (!first) {
@@ -23,7 +27,11 @@ class PrimitiveArrayValueWriter extends ArrayValueWriter {
       ValueWriters.WRITERS.write(elem, context);
       first = false;
     }
-    context.output.append(" ]");
+
+    if (context.getTomlWriter().wantSpaceyArrays()) {
+      context.output.append(' ');
+    }
+    context.output.append(']');
   }
 
   private PrimitiveArrayValueWriter() {}

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

@@ -26,6 +26,7 @@ import static com.moandjiezana.toml.ValueWriters.WRITERS;
 public class TomlWriter {
 
   private WriterIndentationPolicy indentationPolicy = new WriterIndentationPolicy();
+  private boolean wantSpaceyArraysValue = true;
 
   /**
    * Creates a TomlWriter instance.
@@ -93,4 +94,35 @@ public class TomlWriter {
     this.indentationPolicy = indentationPolicy;
     return this;
   }
+
+  /**
+   * <p>Control spacing around array brackets in the TOML output.</p>
+   *
+   * <p>Spacey arrays = true (default):</p>
+   *
+   * <pre><code>
+   *   a = [ 1, 2, 3 ]
+   * </code></pre>
+   *
+   * <p>Spacey arrays = false:</p>
+   *
+   * <pre><code>
+   *   a = [1, 2, 3]
+   * </code></pre>
+   *
+   * @param value spacey arrays setting
+   * @return this TomlWriter instance
+   */
+  public TomlWriter wantSpaceyArrays(boolean value) {
+    this.wantSpaceyArraysValue = value;
+    return this;
+  }
+
+  /**
+   * Get the current array whitespace policy
+   * @return the current policy
+   */
+  public boolean wantSpaceyArrays() {
+    return wantSpaceyArraysValue;
+  }
 }

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

@@ -79,4 +79,8 @@ class WriterContext {
 
     return new String(chars);
   }
+
+  public TomlWriter getTomlWriter() {
+    return tomlWriter;
+  }
 }