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