StringReader.c

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/*
 * Objectively: Ultra-lightweight object oriented framework for GNU C.
 * Copyright (C) 2014 Jay Dolan <jay@jaydolan.com>
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source distribution.
 */
 
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
 
#include "StringReader.h"
 
#define _Class _StringReader
 
#pragma mark - Object
 
static Object *copy(const Object *self) {
 
  StringReader *this = (StringReader *) self;
 
  return (Object *) $(alloc(StringReader), initWithString, this->string);
}
 
static void dealloc(Object *self) {
 
  StringReader *this = (StringReader *) self;
 
  release(this->string);
 
  super(Object, self, dealloc);
}
 
#pragma mark - StringReader
 
static StringReader *initWithCharacters(StringReader *self, const char *chars) {
 
  String *string = str(chars);
 
  self = $(self, initWithString, string);
 
  release(string);
 
  return self;
}
 
static StringReader *initWithString(StringReader *self, String *string) {
 
  self = (StringReader *) super(Object, self, init);
  if (self) {
    self->string = retain(string);
    $(self, reset);
  }
  return self;
}
 
static Unicode next(StringReader *self, StringReaderMode mode) {
  Unicode c;
 
  const int bytes = mbtowc(&c, self->head, MB_CUR_MAX);
  if (bytes > 0) {
    if (mode == StringReaderRead) {
      self->head += bytes;
    }
    return c;
  }
 
  return READER_EOF;
}
 
static Unicode peek(StringReader *self) {
  return $(self, next, StringReaderPeek);
}
 
static Unicode stringReaderRead(StringReader *self) {
  return $(self, next, StringReaderRead);
}
 
static String *readToken(StringReader *self, const Unicode *charset, Unicode *stop) {
 
  while (true) {
    const Unicode c = $(self, peek);
    if (c == READER_EOF || wcschr(charset, c) == NULL) {
      break;
    }
    $(self, read);
  }
 
  const char *start = self->head;
 
  while (true) {
    const Unicode c = $(self, peek);
    if (c == READER_EOF || wcschr(charset, c)) {
      if (stop) {
        *stop = c;
      }
      break;
    }
    $(self, read);
  }
 
  if (self->head - start > 0) {
    const Range range = {
      .location = start - self->string->chars,
      .length = self->head - start
    };
    return $(self->string, substring, range);
  }
 
  return NULL;
}
 
static void reset(StringReader *self) {
  self->head = self->string->chars;
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
  ((ObjectInterface *) clazz->interface)->copy = copy;
  ((ObjectInterface *) clazz->interface)->dealloc = dealloc;
 
  ((StringReaderInterface *) clazz->interface)->initWithCharacters = initWithCharacters;
  ((StringReaderInterface *) clazz->interface)->initWithString = initWithString;
  ((StringReaderInterface *) clazz->interface)->next = next;
  ((StringReaderInterface *) clazz->interface)->peek = peek;
  ((StringReaderInterface *) clazz->interface)->read = stringReaderRead;
  ((StringReaderInterface *) clazz->interface)->readToken = readToken;
  ((StringReaderInterface *) clazz->interface)->reset = reset;
}
 
Class *_StringReader(void) {
  static Class *clazz;
  static Once once;
 
  do_once(&once, {
    clazz = _initialize(&(const ClassDef) {
      .name = "StringReader",
      .superclass = _Object(),
      .instanceSize = sizeof(StringReader),
      .interfaceOffset = offsetof(StringReader, interface),
      .interfaceSize = sizeof(StringReaderInterface),
      .initialize = initialize,
    });
  });
 
  return clazz;
}
 
#undef _Class