From 9b443c9a4dc8846ff1cc255abee19909800343cb Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Fri, 17 Jan 2025 14:06:30 -0500
Subject: [PATCH] add utility function to compare two string while ignoring
 whitespace

---
 doc/src/Developer_utils.rst   |  3 +++
 src/utils.cpp                 | 23 +++++++++++++++++++++++
 src/utils.h                   |  8 ++++++++
 unittest/utils/test_utils.cpp | 16 ++++++++++++++++
 4 files changed, 50 insertions(+)

diff --git a/doc/src/Developer_utils.rst b/doc/src/Developer_utils.rst
index 402ed680f7..2f9dce86d4 100644
--- a/doc/src/Developer_utils.rst
+++ b/doc/src/Developer_utils.rst
@@ -166,6 +166,9 @@ and parsing files or arguments.
 .. doxygenfunction:: split_lines
    :project: progguide
 
+.. doxygenfunction:: strsame
+   :project: progguide
+
 .. doxygenfunction:: strmatch
    :project: progguide
 
diff --git a/src/utils.cpp b/src/utils.cpp
index 90d165202a..b72a9f1be3 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -111,6 +111,29 @@ bool utils::strmatch(const std::string &text, const std::string &pattern)
   return (pos >= 0);
 }
 
+bool utils::strsame(const std::string &text1, const std::string &text2)
+{
+  const char *ptr1 = text1.c_str();
+  const char *ptr2 = text2.c_str();
+
+  while (*ptr1 && *ptr2) {
+
+    // ignore whitespace
+    while (*ptr1 && isblank(*ptr1)) ++ptr1;
+    while (*ptr2 && isblank(*ptr2)) ++ptr2;
+
+    // strings differ
+    if (*ptr1 != *ptr2) return false;
+
+    // reached end of both strings
+    if (!*ptr1 && !*ptr2) return true;
+
+    ++ptr1;
+    ++ptr2;
+  }
+  return true;
+}
+
 /** This function is a companion function to utils::strmatch(). Arguments
  *  and logic is the same, but instead of a boolean, it returns the
  *  sub-string that matches the regex pattern.  There can be only one match.
diff --git a/src/utils.h b/src/utils.h
index 1854c07cf5..1d1ce27de5 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -41,6 +41,14 @@ namespace utils {
 
   bool strmatch(const std::string &text, const std::string &pattern);
 
+  /*! Compare two string while ignoring whitespace
+   *
+   *  \param text1 the first text to be compared
+   *  \param text2 the second text to be compared
+   *  \return true if the non-whitespace part of the two strings matches, false if not */
+
+  bool strsame(const std::string &text1, const std::string &text2);
+
   /*! Find sub-string that matches a simplified regex pattern
    *
    *  \param text the text to be matched against the pattern
diff --git a/unittest/utils/test_utils.cpp b/unittest/utils/test_utils.cpp
index 510fcb0198..2a46de43f7 100644
--- a/unittest/utils/test_utils.cpp
+++ b/unittest/utils/test_utils.cpp
@@ -46,6 +46,22 @@ TEST(Utils, strdup)
     delete[] copy2;
 }
 
+TEST(Utils, strsame)
+{
+    std::string text1("some_text");
+    std::string text2("some_text");
+    ASSERT_TRUE(utils::strsame(text1,text2));
+    text1 = " some   _\ttext\n ";
+    ASSERT_TRUE(utils::strsame(text1,text2));
+    text2 = "  some _  text\n    ";
+    ASSERT_TRUE(utils::strsame(text1,text2));
+
+    text2 = "some_other_text";
+    ASSERT_FALSE(utils::strsame(text1,text2));
+    text2 = " some other_text";
+    ASSERT_FALSE(utils::strsame(text1,text2));
+}
+
 TEST(Utils, trim)
 {
     auto trimmed = utils::trim("\t some text");