1 files changed, 62 insertions, 0 deletions
diff --git a/src/replace_digits.hpp b/src/replace_digits.hpp
new file mode 100644
index 0000000..e8ac957
--- /dev/null
+++ b/src/replace_digits.hpp
@@ -0,0 +1,62 @@
+/** \file \author Jonathan Graehl <graehl@gmail.com>
+
+    replace 0-9 ascii chars with another ascii replacement
+
+    To the extent possible under law, the author(s) have dedicated all copyright
+    and related and neighboring rights to this software to the public domain
+    worldwide. This software is distributed without any warranty.
+*/
+
+#ifndef REPLACEDIGITS_GRAEHL_2015_06_25_H
+#define REPLACEDIGITS_GRAEHL_2015_06_25_H
+#pragma once
+
+#include <string>
+#include <utility>
+
+namespace graehl {
+
+inline bool ascii_digit(char c) {
+  return c >= '0' && c <= '9';
+}
+
+struct replace_digits {
+  char map_digits;
+  replace_digits(char map_digits = '@') : map_digits(map_digits) {}
+
+  /// \return whether anything was replaced
+  bool replaced(char* i, char* end) const {
+    for (; i != end; ++i)
+      if (ascii_digit(*i)) {
+        *i = map_digits;
+        while (++i != end)
+          if (ascii_digit(*i)) *i = map_digits;
+        return true;
+      }
+    return false;
+  }
+  /// maybe: only if non-0 map_digits, do the thing
+  bool maybe_replaced(char* i, char* end) const { return map_digits && replaced(i, end); }
+
+  void replace(char* i, char* end) const {
+    for (; i != end; ++i)
+      if (ascii_digit(*i)) *i = map_digits;
+  }
+  void maybe_replace(char* i, char* end) const {
+    if (map_digits) replace(i, end);
+  }
+
+  void replace(std::string& str, std::string::size_type i = 0) const {
+    std::string::size_type n = str.size();
+    char* d = (char *)str.data(); // although only C++11 officially allows this, in reality everyone does
+    replace(d + i, d + n);
+  }
+  void maybe_replace(std::string& str, std::string::size_type i = 0) const {
+    if (map_digits) replace(str, i);
+  }
+};
+
+
+}
+
+#endif