Add scrstring module

include/scrstring.mfk

@@ -0,0 +1,61 @@
+import string
+
+#if NULLCHAR_SAME
+alias scrstrzlen = strzlen
+alias scrstrzcmp = strzcmp
+alias scrstrzcopy = strzcopy
+alias scrstrzappendchar = strzappendchar
+alias scrstrz2word = strz2word
+alias scrstrzappend = strzappend
+
+
+#else
+
+#if ARCH_I80
+import scrstring_fastpointers
+#else
+import scrstring_fastindices
+#endif
+
+void scrstrzappend(pointer buffer, pointer str) {
+    scrstrzcopy(buffer + scrstrzlen(buffer), str)
+}
+void scrstrzappendchar(pointer buffer, byte char) {
+   buffer += scrstrzlen(buffer)
+   buffer[0] = char
+   buffer[1] = nullchar_scr
+}
+
+word scrstrz2word(pointer str) {
+    byte i
+    byte char
+    word next
+    word result
+    result = 0
+    i = 0
+    errno = err_ok
+    while true {
+        char = str[i]
+        if char == nullchar_scr {
+            if i == 0 {
+                errno = err_numberformat
+            }
+            return result
+        }
+        if '0'scr <= char <= '0'scr + 9 {
+            next = result * 10
+            next += char - '0'scr
+            if next < result {
+                errno = err_range
+            }
+            result = next
+        } else {
+            errno = err_numberformat
+            return result
+        }
+        i += 1
+    }
+}
+
+
+#endif

include/scrstring_fastindices.mfk

@@ -0,0 +1,41 @@
+#if NULLCHAR_SAME
+#error The module scrstring_fastindices should not be included directly
+#endif
+
+byte scrstrzlen(pointer str) {
+    byte index
+    index = 0
+    while str[index] != nullchar_scr {
+        index += 1
+    }
+    return index
+}
+
+sbyte scrstrzcmp(pointer str1, pointer str2) {
+    byte i1
+    byte i2
+    i1 = 0
+    i2 = 0
+    while true {
+        if str1[i1] != str2[i2] {
+            if str1[i1] < str2[i2] { return -1 }
+            return 1
+        }
+        if str1[i1] == nullchar_scr {
+            return 0
+        }
+        i1 += 1
+        i2 += 1
+    }
+}
+
+void scrstrzcopy(pointer dest, pointer src) {
+    byte i
+    byte c
+    i = 0
+    do {
+        c = src[i]
+        dest[i] = c
+        i += 1
+    } while c != nullchar_scr
+}

include/scrstring_fastpointers.mfk

@@ -0,0 +1,55 @@
+#if NULLCHAR_SAME
+#error The module scrstring_fastpointers should not be included directly
+#endif
+
+#pragma zilog_syntax
+
+byte scrstrzlen(pointer str) {
+    pointer end
+    end = str
+    while end[0] != nullchar_scr {
+        end += 1
+    }
+    return lo(end - str)
+}
+
+sbyte scrstrzcmp(pointer str1, pointer str2) {
+    while true {
+        if str1[0] == nullchar_scr {
+            if str2[0] == nullchar_scr {
+                return 0
+            } else {
+                return -1
+            }
+        } else if str1[0] != str2[0] {
+            if str1[0] < str2[0] { return -1 }
+            return 1
+        }
+        str1 += 1
+        str2 += 1
+    }
+}
+
+#if CPUFEATURE_Z80 || CPUFEATURE_8080
+void scrstrzcopy(pointer dest, pointer src) {
+    asm {
+        ? LD HL,(src)
+        ? LD DE,(dest)
+    ___scrstrzcopy_loop:
+        LD A,(HL)
+        LD (DE),A
+        ? CP nullchar_scr
+        ? JP NZ, ___scrstrzcopy_loop
+    }
+}
+#else
+void scrstrzcopy(pointer dest, pointer src) {
+    byte c
+    do {
+        c = src[0]
+        dest[0] = c
+        src += 1
+        dest += 1
+    } while c != nullchar_scr
+}
+#endif