1 files changed, 60 insertions, 0 deletions
diff --git a/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/Token.java b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/Token.java
new file mode 100644
index 00000000000..a83dab72025
--- /dev/null
+++ b/node-admin/src/main/java/com/yahoo/vespa/hosted/node/admin/task/util/template/Token.java
@@ -0,0 +1,60 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.hosted.node.admin.task.util.template;
+
+import com.yahoo.vespa.hosted.node.admin.task.util.text.Cursor;
+import com.yahoo.vespa.hosted.node.admin.task.util.text.CursorRange;
+
+import java.util.Optional;
+
+/**
+ * @author hakonhall
+ */
+class Token {
+    static final char NEGATE_CHAR = '!';
+    static final char REMOVE_NEWLINE_CHAR = '-';
+    static final char VARIABLE_DIRECTIVE_CHAR = '=';
+
+    static Optional<String> skipId(Cursor cursor) {
+        if (cursor.eot() || !isIdStart(cursor.getChar())) return Optional.empty();
+
+        Cursor start = new Cursor(cursor);
+        cursor.increment();
+
+        while (!cursor.eot() && isIdPart(cursor.getChar()))
+            cursor.increment();
+
+        return Optional.of(new CursorRange(start, cursor).string());
+    }
+
+    /** A delimiter either starts a directive (e.g. %{) or ends it (e.g. }). */
+    static String verifyDelimiter(String delimiter) {
+        if (!isAsciiToken(delimiter)) {
+            throw new IllegalArgumentException("Invalid delimiter: '" + delimiter + "'");
+        }
+        return delimiter;
+    }
+
+    /** Returns true for a non-empty string with only ASCII token characters. */
+    private static boolean isAsciiToken(String string) {
+        if (string.isEmpty()) return false;
+        for (char c : string.toCharArray()) {
+            if (!isAsciiTokenChar(c)) return false;
+        }
+        return true;
+    }
+
+    /** Returns true if char is a printable ASCII character except space (isgraph(3)). */
+    private static boolean isAsciiTokenChar(char c) {
+        // 0x1F unit separator
+        // 0x20 space
+        // 0x21 !
+        // ...
+        // 0x7E ~
+        // 0x7F del
+        return 0x20 < c && c < 0x7F;
+    }
+
+    // Our identifiers are equivalent to a Java identifiers.
+    private static boolean isIdStart(char c) { return Character.isJavaIdentifierStart(c); }
+    private static boolean isIdPart(char c) { return Character.isJavaIdentifierPart(c); }
+}