1 files changed, 46 insertions, 0 deletions
diff --git a/src/main/java/moe/nea/zwirn/GoodStringReader.java b/src/main/java/moe/nea/zwirn/GoodStringReader.java
new file mode 100644
index 0000000..a396120
--- /dev/null
+++ b/src/main/java/moe/nea/zwirn/GoodStringReader.java
@@ -0,0 +1,46 @@
+package moe.nea.zwirn;
+
+import java.util.Stack;
+
+public class GoodStringReader {
+    final String source;
+    Stack<Integer> stack = new Stack<>();
+    int index = 0;
+
+    public GoodStringReader(String source) {
+        this.source = source;
+    }
+
+    public void push() {
+        stack.push(index);
+    }
+
+    public void reset() {
+        index = stack.pop();
+    }
+
+    public void discard() {
+        stack.pop();
+    }
+
+    public char nextChar() {
+        return source.charAt(index++);
+    }
+
+    public String readUntil(char... cs) {
+        int minI = -1;
+        for (char c : cs) {
+            int i = source.indexOf(c, index);
+            if (i < 0) continue;
+            minI = minI < 0 ? i : Math.min(minI, i);
+        }
+        if (minI < 0) return null;
+        int startIndex = index;
+        index = minI + 1;
+        return source.substring(startIndex, index - 1);
+    }
+
+    public char peekChar() {
+        return source.charAt(index);
+    }
+}