add strcompress function and use it for error output

doc/src/Developer_utils.rst

@@ -133,6 +133,9 @@ and parsing files or arguments.
 .. doxygenfunction:: trim_comment
    :project: progguide
 
+.. doxygenfunction:: strcompress
+   :project: progguide
+
 .. doxygenfunction:: strip_style_suffix
    :project: progguide
 

src/utils.cpp

@@ -119,8 +119,8 @@ bool utils::strsame(const std::string &text1, const std::string &text2)
   while (*ptr1 && *ptr2) {
 
     // ignore whitespace
-    while (*ptr1 && isblank(*ptr1)) ++ptr1;
+    while (*ptr1 && isspace(*ptr1)) ++ptr1;
-    while (*ptr2 && isblank(*ptr2)) ++ptr2;
+    while (*ptr2 && isspace(*ptr2)) ++ptr2;
 
     // strings differ
     if (*ptr1 != *ptr2) return false;
@@ -134,6 +134,32 @@ bool utils::strsame(const std::string &text1, const std::string &text2)
   return true;
 }
 
+std::string utils::strcompress(const std::string &text)
+{
+  const char *ptr = text.c_str();
+  std::string output;
+
+  // remove leading whitespace
+  while (*ptr && isspace(*ptr)) ++ptr;
+
+  while (*ptr) {
+    // copy non-blank characters
+    while (*ptr && !isspace(*ptr)) output += *ptr++;
+
+    if (!*ptr) break;
+
+    // add one blank only
+    if (isspace(*ptr)) output += ' ';
+
+    // skip additional blanks
+    while (*ptr && isspace(*ptr)) ++ptr;
+  }
+
+  // remove trailing blank
+  if (output.back() == ' ') output.erase(output.size() - 1, 1);
+  return output;
+}
+
 /** 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.
@@ -158,7 +184,7 @@ void utils::missing_cmd_args(const std::string &file, int line, const std::strin
 std::string utils::point_to_error(Input *input, int failed)
 {
   if (input) {
-    std::string lastline = input->line;
+    std::string lastline = utils::strcompress(input->line);
     std::string lastargs = input->command;
     std::string cmdline = "Last input line: ";
 

src/utils.h

@@ -35,20 +35,27 @@ namespace utils {
 
   /*! Match text against a simplified regex pattern
    *
-   *  \param text the text to be matched against the pattern
+   *  \param  text     the text to be matched against the pattern
-   *  \param pattern the search pattern, which may contain regexp markers
+   *  \param  pattern  the search pattern, which may contain regexp markers
    *  \return true if the pattern matches, false if not */
 
   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  text1   the first text to be compared
-   *  \param text2 the second 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);
 
+  /*! Compress whitespace in a string
+   *
+   *  \param  text  the text to be compressed
+   *  \return string with whitespace compressed to single blanks */
+
+  std::string strcompress(const std::string &text);
+
   /*! Find sub-string that matches a simplified regex pattern
    *
    *  \param text the text to be matched against the pattern

unittest/utils/test_utils.cpp

@@ -50,16 +50,43 @@ TEST(Utils, strsame)
 {
     std::string text1("some_text");
     std::string text2("some_text");
-    ASSERT_TRUE(utils::strsame(text1,text2));
+    ASSERT_TRUE(utils::strsame(text1, text2));
     text1 = " some   _\ttext\n ";
-    ASSERT_TRUE(utils::strsame(text1,text2));
+    ASSERT_TRUE(utils::strsame(text1, text2));
     text2 = "  some _  text\n    ";
-    ASSERT_TRUE(utils::strsame(text1,text2));
+    ASSERT_TRUE(utils::strsame(text1, text2));
 
     text2 = "some_other_text";
-    ASSERT_FALSE(utils::strsame(text1,text2));
+    ASSERT_FALSE(utils::strsame(text1, text2));
     text2 = " some other_text";
-    ASSERT_FALSE(utils::strsame(text1,text2));
+    ASSERT_FALSE(utils::strsame(text1, text2));
+}
+
+TEST(Utils, strcompress)
+{
+    auto compressed = utils::strcompress("\t some   text   ");
+    ASSERT_THAT(compressed, StrEq("some text"));
+
+    compressed = utils::strcompress("some \ntext");
+    ASSERT_THAT(compressed, StrEq("some text"));
+
+    compressed = utils::strcompress("sometext");
+    ASSERT_THAT(compressed, StrEq("sometext"));
+
+    compressed = utils::strcompress("some   text \r\n");
+    ASSERT_THAT(compressed, StrEq("some text"));
+
+    compressed = utils::strcompress("some other  text \r\n");
+    ASSERT_THAT(compressed, StrEq("some other text"));
+
+    compressed = utils::strcompress("\v some	 text \f");
+    ASSERT_THAT(compressed, StrEq("some text"));
+
+    compressed = utils::strcompress("   some\t text    ");
+    ASSERT_THAT(compressed, StrEq("some text"));
+
+    compressed = utils::strcompress("  \t\n   ");
+    ASSERT_THAT(compressed, StrEq(""));
 }
 
 TEST(Utils, trim)