Simplify use of signed vs unsigned.

Fixes various compiler warnings. Unsigned chars are now restricted
to the UTF-8 and PatternMatcher functions.

Field.c

@@ -143,7 +143,7 @@ int Field_run(Field* this, bool setCursor, bool* handled, bool* code) {
       Display_move(this->y, this->x + this->labelLen + 2 + this->cursor);
       Display_attrset(A_REVERSE);
       if (this->cursor < Text_chars(curr->text)) {
-         const unsigned char* ch = Text_stringAt(curr->text, this->cursor);
+         const char* ch = Text_stringAt(curr->text, this->cursor);
          Display_writeAtn(this->y, x + this->cursor, ch, UTF8_bytes(*ch));
       } else {
          Display_writeAtn(this->y, x + this->cursor, " ", 1);

Highlight.c

@@ -56,7 +56,7 @@ struct ReadHighlightFileArgs_ {
 };
 
 struct MatchArgs_ {
-   const unsigned char* buffer;
+   const char* buffer;
    int* attrs;
    GraphNode* rules;
    GraphNode* follows;
@@ -349,15 +349,15 @@ HighlightContext* Highlight_addContext(Highlight* this, char* open, char* close,
 #define PAINT(_args, _here, _attr) do { _args->attrs[_args->attrsAt++] = _attr; _here = UTF8_forward(_here, 1); } while(0)
 
 static inline void Highlight_tryMatch(Highlight* this, MatchArgs* args, bool paintUnmatched) {
-   const unsigned char* here = args->buffer;
+   const char* here = args->buffer;
    intptr_t intColor;
    bool eager;
    intptr_t matchlen = args->match(args->rules, args->buffer, &intColor, &eager);
    Color color = (Color) intColor;
    assert(color >= 0 && color < Colors);
    if (matchlen && (eager || ( !(isword(here[matchlen-1]) && isword(here[matchlen]))))) {
       int attr = CRT_colors[color];
-      const unsigned char* nextStop = here + matchlen;
+      const char* nextStop = here + matchlen;
       while (here < nextStop) {
          PAINT(args, here, attr);
       }
@@ -385,7 +385,7 @@ static inline void Highlight_tryMatch(Highlight* this, MatchArgs* args, bool pai
    args->buffer = here;
 }
 
-void Highlight_setAttrs(Highlight* this, const unsigned char* buffer, int* attrs, int len, int y) {
+void Highlight_setAttrs(Highlight* this, const char* buffer, int* attrs, int len, int y) {
    MatchArgs args = {
       .buffer = buffer,
       .attrs = attrs,

Line.c

@@ -92,10 +92,10 @@ void Line_display(Object* cast, RichString* str) {
 
    Highlight_setAttrs(hl, this->text.data, hlAttrs, this->text.bytes, y + 1);
 
-   const unsigned char* start = Text_toString(this->text);
+   const char* start = Text_toString(this->text);
    int attrIdx = 0;
 
-   for (const unsigned char* curr = start; *curr; ) {
+   for (const char* curr = start; *curr; ) {
       int inIdx = curr - start;
       if (*curr == '\t') {
          int tabSize = tabWidth - (outIdx % tabWidth);
@@ -216,26 +216,26 @@ int Line_breakAt(Line* this, int at, bool doIndent) {
 void Line_joinNext(Line* this) {
    assert(this->super.next);
    Line* next = (Line*) this->super.next;
-   Text_strcat(&(this->text), next->text);
+   (void) Text_strcat(&(this->text), next->text);
    ListItem_remove((ListItem*) next);
 }
 
-static int lineToBufferFromTo(StringBuffer* str, Line* l, int xFrom, int xTo) {
+static void lineToBufferFromTo(StringBuffer* str, Line* l, int xFrom, int xTo) {
    const char* from = Text_stringAt(l->text, xFrom);
    const char* to = Text_stringAt(l->text, xTo);
    StringBuffer_addN(str, from, to - from);
 }
 
-static int lineToBufferFrom(StringBuffer* str, Line* l, int xFrom) {
-   const unsigned char* from = Text_stringAt(l->text, xFrom);
+static void lineToBufferFrom(StringBuffer* str, Line* l, int xFrom) {
+   const char* from = Text_stringAt(l->text, xFrom);
    StringBuffer_addN(str, from, Text_toString(l->text) + Text_bytes(l->text) - from);
 }
 
-static int lineToBufferTo(StringBuffer* str, Line* l, int xTo) {
+static void lineToBufferTo(StringBuffer* str, Line* l, int xTo) {
    StringBuffer_addN(str, Text_toString(l->text), Text_bytesUntil(l->text, xTo));
 }
 
-static int lineToBuffer(StringBuffer* str, Line* l) {
+static void lineToBuffer(StringBuffer* str, Line* l) {
    StringBuffer_addN(str, Text_toString(l->text), Text_bytes(l->text));
 }
 
@@ -340,7 +340,7 @@ int* Line_unindent(Line* this, int lines, int indentSpaces) {
 bool Line_insertBlock(Line* this, int x, Text block, int* newX, int* newY) {
    // newY must contain the current value of y on input
    int blockBytes = Text_bytes(block);
-   unsigned char* nl = memchr(block.data, '\n', block.bytes);
+   char* nl = memchr(block.data, '\n', block.bytes);
    Line* at = this;
    bool multiline = (nl);
    if (!multiline) {
@@ -351,11 +351,11 @@ bool Line_insertBlock(Line* this, int x, Text block, int* newX, int* newY) {
       Line_breakAt(this, x, 0);
       Line* last = (Line*) this->super.next;
       Text_insertString(&(this->text), x, block.data, lineLen);
-      unsigned char* walk = ++nl;
+      char* walk = ++nl;
       (*newY)++;
       while ( (nl = memchr(walk, '\n', blockBytes - (walk - block.data) )) ) {
          lineLen = nl - walk;
-         char* text = malloc(lineLen+1);
+         char* text = (char*) malloc(lineLen+1);
          text[lineLen] = '\0';
          memcpy(text, walk, lineLen);
          Line* newLine = Line_new(this->super.list, Text_new(text), this->context);

Object.c

@@ -49,8 +49,8 @@ void Object_delete(Object* this) {
 }
 
 void Object_display(Object* this, RichString* out) {
-   unsigned char objAddress[50];
-   sprintf((char*)objAddress, "O:%p C:%p", (void*) this, (void*) this->class);
+   char objAddress[50];
+   sprintf(objAddress, "O:%p C:%p", (void*) this, (void*) this->class);
    RichString_write(out, 0, objAddress);
 }
 

PatternMatcher.c

@@ -8,7 +8,7 @@
 
 /*{
 
-typedef int(*Method_PatternMatcher_match)(GraphNode*, const unsigned char*, intptr_t*, bool*);
+typedef int(*Method_PatternMatcher_match)(GraphNode*, const char*, intptr_t*, bool*);
 
 struct GraphNode_ {
    unsigned char min;
@@ -181,7 +181,8 @@ void PatternMatcher_add(PatternMatcher* this, unsigned char* pattern, intptr_t v
    }
 }
 
-bool PatternMatcher_partialMatch(GraphNode* node, unsigned char* input, int inputLen, char* rest, int restLen) {
+bool PatternMatcher_partialMatch(GraphNode* node, const char* sinput, int inputLen, char* rest, int restLen) {
+   const unsigned char* input = (const unsigned char*) sinput;
    int i = 0;
    while (i < inputLen) {
       node = GraphNode_follow(node, input[i]);
@@ -203,7 +204,8 @@ bool PatternMatcher_partialMatch(GraphNode* node, unsigned char* input, int inpu
    return false;
 }
 
-int PatternMatcher_match(GraphNode* node, const unsigned char* input, intptr_t* value, bool* eager) {
+int PatternMatcher_match(GraphNode* node, const char* sinput, intptr_t* value, bool* eager) {
+   const unsigned char* input = (const unsigned char*) sinput;
    int i = 0;
    int match = 0;
    *value = 0;
@@ -221,7 +223,8 @@ int PatternMatcher_match(GraphNode* node, const unsigned char* input, intptr_t*
    return match;
 }
 
-int PatternMatcher_match_toLower(GraphNode* node, const unsigned char* input, intptr_t* value, bool* eager) {
+int PatternMatcher_match_toLower(GraphNode* node, const char* sinput, intptr_t* value, bool* eager) {
+   const unsigned char* input = (const unsigned char*) sinput;
    int i = 0;
    int match = 0;
    *value = 0;

Script.c

@@ -195,7 +195,7 @@ static int Script_Buffer___newindex(lua_State* L) {
       luaL_checkstring(L, 3);
       size_t len;
       const char* text = lua_tolstring(L, 3, &len);
-      Buffer_setLine(buffer, y, Text_new((unsigned char*)text));
+      Buffer_setLine(buffer, y, Text_new((char*) text));
    }
    return 0;
 }
@@ -377,7 +377,7 @@ void Script_highlightFile(Highlight* this, const char* fileName) {
    this->hasScript = callFunction(this->L, "highlight_file", fileName);
 }
 
-void Script_highlightLine(Highlight* this, const unsigned char* buffer, int* attrs, int len, int y) {
+void Script_highlightLine(Highlight* this, const char* buffer, int* attrs, int len, int y) {
    lua_State* L = this->L;
    if (!this->hasScript)
       return;

TabManager.c

@@ -259,7 +259,7 @@ void TabManager_resize(TabManager* this, int w, int h) {
    this->redrawBar = true;
 }
 
-int TabManager_find(TabManager* this, const char* name) {
+int TabManager_find(TabManager* this, char* name) {
    int items = Vector_size(this->items);
    for (int i = 0; i < items; i++) {
       TabPage* page = (TabPage*) Vector_get(this->items, i);
@@ -340,7 +340,7 @@ char* TabManager_getPageName(TabManager* this, int i) {
    }
 }
 
-void TabManager_load(TabManager* this, const char* fileName, int limit) {
+void TabManager_load(TabManager* this, char* fileName, int limit) {
    FILE* fd = Files_openHome("r", fileName, NULL);
    if (fd) {
       char line[4097];
@@ -350,8 +350,8 @@ void TabManager_load(TabManager* this, const char* fileName, int limit) {
             char* enter = strrchr(line, '\n');
             if (enter) *enter = '\0';
             if (*line == '\0') continue;
-            if (TabManager_find(this, line) == -1 && access(line, F_OK) == 0) {
-               TabManager_add(this, line, NULL);
+            if (TabManager_find(this, (char*) line) == -1 && access(line, F_OK) == 0) {
+               TabManager_add(this, (char*) line, NULL);
                limit--;
                if (!limit) break;
             }
@@ -361,7 +361,7 @@ void TabManager_load(TabManager* this, const char* fileName, int limit) {
    }
 }
 
-void TabManager_save(TabManager* this, const char* fileName) {
+void TabManager_save(TabManager* this, char* fileName) {
    FILE* fd = Files_openHome("w", fileName, NULL);
    if (fd) {
       int items = Vector_size(this->items);