Refactor show_whitespaces a bit

1 files changed, 16 insertions, 28 deletions

diff --git a/src/highlighters.cc b/src/highlighters.cc
index 4498213d..358387e9 100644
--- a/src/highlighters.cc
+++ b/src/highlighters.cc
@@ -682,7 +682,8 @@ void expand_tabulations(const Context& context, HighlightFlags flags, DisplayBuf
 }
 
 void show_whitespaces(const Context& context, HighlightFlags flags, DisplayBuffer& display_buffer, BufferRange,
-                      const String& character_tab, const String& character_tabpad, const String& character_spc, const String& character_lf, const String& character_nbsp)
+                      StringView tab, StringView tabpad,
+                      StringView spc, StringView lf, StringView nbsp)
 {
     const int tabstop = context.options()["tabstop"].get<int>();
     auto whitespaceface = get_face("Whitespace");
@@ -711,14 +712,14 @@ void show_whitespaces(const Context& context, HighlightFlags flags, DisplayBuffe
                     {
                         int column = (int)get_column(buffer, tabstop, it.coord());
                         int count = tabstop - (column % tabstop);
-                        atom_it->replace(character_tab + String(character_tabpad[(CharCount)0], CharCount{count-1}));
+                        atom_it->replace(tab + String(tabpad[(CharCount)0], CharCount{count-1}));
                     }
                     else if (cp == ' ')
-                        atom_it->replace(character_spc);
+                        atom_it->replace(spc.str());
                     else if (cp == '\n')
-                        atom_it->replace(character_lf);
+                        atom_it->replace(lf.str());
                     else if (cp == 0xA0)
-                        atom_it->replace(character_nbsp);
+                        atom_it->replace(nbsp.str());
                     atom_it->face = whitespaceface;
                     break;
                 }
@@ -739,32 +740,19 @@ HighlighterAndId show_whitespaces_factory(HighlighterParameters params)
     };
     ParametersParser parser(params, param_desc);
 
-    StringView character_tab = parser.get_switch("tab").value_or("→");
-    if (character_tab.char_length() != 1)
-        throw runtime_error("Tabulation character length is limited to 1");
-
-    StringView character_tabpad = parser.get_switch("tabpad").value_or(" ");
-    if (character_tabpad.char_length() != 1)
-        throw runtime_error("Tabulation padding character length is limited to 1");
-
-    StringView character_spc = parser.get_switch("spc").value_or("·");
-    if (character_spc.char_length() > 1)
-        throw runtime_error("Space character length is limited to 1");
-
-    StringView character_lf = parser.get_switch("lf").value_or("¬");
-    if (character_lf.char_length() > 1)
-        throw runtime_error("Line feed character length is limited to 1");
-
-    StringView character_nbsp = parser.get_switch("nbsp").value_or("⍽");
-    if (character_nbsp.char_length() > 1)
-        throw runtime_error("Non breakable space character length is limited to 1");
+    auto get_param = [&](StringView param,  StringView fallback) {
+        StringView value = parser.get_switch(param).value_or(fallback);
+        if (value.char_length() != 1)
+            throw runtime_error{format("-{} expects a single character parmeter", param)};
+        return value.str();
+    };
 
     using namespace std::placeholders;
     auto func = std::bind(show_whitespaces, _1, _2, _3, _4,
-                          character_tab.str(), character_tabpad.str(),
-                          character_spc.str(),
-                          character_lf.str(),
-                          character_nbsp.str());
+                          get_param("tab", "→"), get_param("tabpad", " "),
+                          get_param("spc", "·"),
+                          get_param("lf", "¬"),
+                          get_param("nbsp", "⍽"));
 
     return {"show_whitespaces", make_simple_highlighter(std::move(func))};
 }