use stringview in cga

c_os/devices/CGA.cc

@@ -17,9 +17,9 @@
 const IOport CGA::index_port(0x3d4);
 const IOport CGA::data_port(0x3d5);
 
-bse::span<CGA::cga_char_t, CGA::ROWS * CGA::COLUMNS> CGA::SCREEN{reinterpret_cast<CGA::cga_char_t*>(0xb8000U)};
+const bse::span<CGA::cga_char_t, CGA::ROWS * CGA::COLUMNS> CGA::SCREEN{reinterpret_cast<CGA::cga_char_t*>(0xb8000U)};
-bse::span<CGA::cga_line_t, CGA::ROWS> CGA::SCREEN_ROWS{reinterpret_cast<CGA::cga_line_t*>(0xb8000U)};
+const bse::span<CGA::cga_line_t, CGA::ROWS> CGA::SCREEN_ROWS{reinterpret_cast<CGA::cga_line_t*>(0xb8000U)};
-CGA::cga_page_t* CGA::SCREEN_PAGE {reinterpret_cast<CGA::cga_page_t*>(0xb8000U)};
+CGA::cga_page_t* const CGA::SCREEN_PAGE {reinterpret_cast<CGA::cga_page_t*>(0xb8000U)};
 
 /*****************************************************************************
  * Methode:         CGA::setpos                                              *
@@ -86,7 +86,7 @@ void CGA::show(unsigned int x, unsigned int y, char character, unsigned char att
         return;
     }
 
-    cga_char_t* pos= SCREEN[x + y * COLUMNS];
+    cga_char_t* pos = SCREEN[x + y * COLUMNS];
     pos->cga_char = character;
     pos->cga_attribute = attrib;
 }
@@ -98,11 +98,11 @@ void CGA::show(unsigned int x, unsigned int y, char character, unsigned char att
  *                  '\n' fuer Zeilenvorschub.                                *
  *                                                                           *
  * Parameter:                                                                *
- *      string      Auszugebende Zeichenkette                                *
+ *      substring      Auszugebende Zeichenkette                                *
  *      n           Laenger der Zeichenkette                                 *
  *      attrib      Attributbyte fuer alle Zeichen der Zeichenkette          *
  *****************************************************************************/
-void CGA::print(const char* string, unsigned int n, unsigned char attrib) const {
+void CGA::print(const bse::string_view string, unsigned char attrib) const {
 
     /* Hier muess Code eingefuegt werden */
 
@@ -110,8 +110,7 @@ void CGA::print(const char* string, unsigned int n, unsigned char attrib) const
     unsigned int cursor_y = 0;  // Don't poll registers every stroke
     getpos(cursor_x, cursor_y);
 
-    for (int byte = 0; byte < n; ++byte) {
+    for (char current : string) {
-        char current = *(string + byte);
         if (current == '\n') {
             cursor_x = 0;
             cursor_y = cursor_y + 1;
@@ -149,14 +148,6 @@ void CGA::print(const char* string, unsigned int n, unsigned char attrib) const
     setpos(cursor_x, cursor_y);
 }
 
-void CGA::print(const bse::string& string, const unsigned int n, const unsigned char attrib) const {
-    print(static_cast<const char*>(string), n, attrib);
-}
-
-void CGA::print(const bse::string& string, const unsigned char attrib) const {
-    print(static_cast<const char*>(string), string.size(), attrib);
-}
-
 /*****************************************************************************
  * Methode:         CGA::scrollup                                            *
  *---------------------------------------------------------------------------*

c_os/devices/CGA.h

@@ -18,6 +18,7 @@
 #include "user/lib/Array.h"
 #include "user/lib/Span.h"
 #include "user/lib/String.h"
+#include "user/lib/StringView.h"
 
 class CGA {
 private:
@@ -77,9 +78,9 @@ public:
         bse::array<cga_line_t, ROWS> cga_page;
     };
 
-    static bse::span<cga_char_t, ROWS * COLUMNS> SCREEN;
+    static const bse::span<cga_char_t, ROWS * COLUMNS> SCREEN;
-    static bse::span<cga_line_t, ROWS> SCREEN_ROWS;
+    static const bse::span<cga_line_t, ROWS> SCREEN_ROWS;
-    static cga_page_t* SCREEN_PAGE;  // No span because can't address anything in [0, 1]
+    static cga_page_t* const SCREEN_PAGE;  // No span because can't address anything in [0, 1]
 
     // Setzen des Cursors in Spalte x und Zeile y.
     static void setpos(unsigned int x, unsigned int y);
@@ -91,9 +92,7 @@ public:
     static void show(unsigned int x, unsigned int y, char character, unsigned char attrib = STD_ATTR);
 
     // Anzeige mehrerer Zeichen ab der aktuellen Cursorposition
-    void print(const char* string, unsigned int n, unsigned char attrib = STD_ATTR) const;
+    void print(const bse::string_view substring, unsigned char attrib = STD_ATTR) const;
-    void print(const bse::string& string, unsigned int n, unsigned char attrib = STD_ATTR) const;
-    void print(const bse::string& string, unsigned char attrib = STD_ATTR) const;
 
     // Verschiebt den Bildschirminhalt um eine Zeile nach oben.
     // Neue Zeile am unteren Bildrand mit Leerzeichen fuellen

c_os/devices/CGA_Stream.cc

@@ -24,7 +24,8 @@
  *                  verwendet werden, um eine Ausgabe zu erzwingen.          *
  *****************************************************************************/
 void CGA_Stream::flush() {
-    print(buffer.data(), pos, attribute(color_bg, color_fg, blink));  // print(buffer...) would work syntactically
+    buffer[pos] = '\0';  // I removed the n argument from print so nullterminate the string
+    print(buffer.data(), attribute(color_bg, color_fg, blink));  // print(buffer...) would work syntactically
                                                                 // but the system wouldn't start, as the bse::array
                                                                 // would be implicitly converted to bse::string and
                                                                 // that is dynamically allocated.