Rdfile reader

storage/ctab/src/main/java/org/openscience/cdk/io/CharIter.java

@@ -0,0 +1,100 @@
+package org.openscience.cdk.io;
+
+/**
+ * Helper class that facilitates the parsing of text data.
+ */
+final class CharIter {
+    private final String string;
+    private int position = 0;
+
+    CharIter(String str) {
+        this.string = str;
+    }
+
+    static boolean isSpace(char c) {
+        return c == ' ';
+    }
+
+    static boolean isDigit(char c) {
+        return c >= '0' && c <= '9';
+    }
+
+    int position() {
+        return position;
+    }
+
+    char next() {
+        return string.charAt(position++);
+    }
+
+    char peek() {
+        return position < string.length() ? string.charAt(position) : '\0';
+    }
+
+    boolean hasNext() {
+        return position < string.length();
+    }
+
+    String rest() {
+        return string.substring(position);
+    }
+
+    void skipWhiteSpace() {
+        while (hasNext()) {
+            if (isSpace(string.charAt(position)))
+                position++;
+            else
+                break;
+        }
+    }
+
+    int nextUnsignedNumber() {
+        if (!hasNext())
+            return -1;
+        if (!isDigit(peek()))
+            return -1;
+        int num = next() - '0';
+        while (hasNext() && isDigit(peek()))
+            num = (10 * num) + (next() - '0');
+        return num;
+    }
+
+    boolean consume(String substring) {
+        if (position + substring.length() > string.length())
+            return false;
+        int mark = position;
+        for (int i = 0; i < substring.length(); i++) {
+            if (substring.charAt(i) != string.charAt(position)) {
+                position = mark; // reset
+                break;
+            }
+            position++;
+        }
+        return position - mark == substring.length();
+    }
+
+    String substring(int beg, int end) {
+        return string.substring(beg, end);
+    }
+
+    void seek(int position) {
+        this.position = position;
+    }
+
+    boolean nextIf(char c) {
+        if (peek() == c) {
+            next();
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(string, 0, position);
+        sb.append('|');
+        sb.append(string.substring(position));
+        return sb.toString();
+    }
+}