minor: allow specifying indentation unit in Printer

core/util.runtime/src/org/jetbrains/kotlin/utils/Printer.java

@@ -23,13 +23,14 @@ import java.util.Collection;
 import java.util.Iterator;
 
 public class Printer {
-    private static final String INDENTATION_UNIT = "    ";
+    private static final String DEFAULT_INDENTATION_UNIT = "    ";
     private static final String LINE_SEPARATOR = System.getProperty("line.separator");
 
     protected final Appendable out;
     private final int maxBlankLines;
 
     private String indent = "";
+    private final String indentUnit;
     private int blankLineCountIncludingCurrent = 0;
     private boolean withholdIndentOnce = false;
 
@@ -37,9 +38,18 @@ public class Printer {
         this(out, Integer.MAX_VALUE);
     }
 
+    public Printer(@NotNull Appendable out, @NotNull String indentUnit) {
+        this(out, Integer.MAX_VALUE, indentUnit);
+    }
+
     public Printer(@NotNull Appendable out, int maxBlankLines) {
+        this(out, maxBlankLines, DEFAULT_INDENTATION_UNIT);
+    }
+
+    public Printer(@NotNull Appendable out, int maxBlankLines, @NotNull String indentUnit) {
         this.out = out;
         this.maxBlankLines = maxBlankLines;
+        this.indentUnit = indentUnit;
     }
 
     private void append(Object o) {
@@ -109,18 +119,18 @@ public class Printer {
 
     @NotNull
     public Printer pushIndent() {
-        indent += INDENTATION_UNIT;
+        indent += indentUnit;
 
         return this;
     }
 
     @NotNull
     public Printer popIndent() {
-        if (indent.length() < INDENTATION_UNIT.length()) {
+        if (indent.length() < indentUnit.length()) {
             throw new IllegalStateException("No indentation to pop");
         }
 
-        indent = indent.substring(INDENTATION_UNIT.length());
+        indent = indent.substring(indentUnit.length());
 
         return this;
     }