SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// Multi-Phasic Applications: SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.c;

import java.util.Arrays;
import java.util.List;
import net.multiphasicapps.collections.UnmodifiableList;

/**
 * Represents an identifier in C.
 *
 * @since 2023/06/04
 */
public final class CIdentifier
    implements Comparable<CIdentifier>, CExpression, CTokenizable
{
    /** The string identifier. */
    protected final String identifier;
    
    /**
     * Initializes the C identifier.
     * 
     * @param __identifier The C identifier.
     * @throws IllegalArgumentException If the identifier contains invalid
     * characters.
     * @throws NullPointerException On null arguments.
     * @since 2023/06/04
     */
    CIdentifier(String __identifier)
        throws IllegalArgumentException, NullPointerException
    {
        if (__identifier == null)
            throw new NullPointerException("NARG");
        
        /* {@squirreljme.error CW0a Identifier cannot be blank.} */
        if (__identifier.isEmpty())
            throw new IllegalArgumentException("CW0a");
        
        // Check identifier
        for (int i = 0, n = __identifier.length(); i < n; i++)
        {
            char c = __identifier.charAt(i);
            
            /* {@squirreljme.error CW01 Identifier cannot start with a number.
            (The identifier)} */
            if (i == 0 && c >= '0' && c <= '9')
                throw new IllegalArgumentException("CW01 " + __identifier);
            
            /* {@squirreljme.error CW09 Identifier contains an invalid
            character. (The identifier)} */
            if (!((c >= 'a' && c <= 'z') ||
                (c >= 'A' && c <= 'Z') ||
                (c >= '0' && c <= '9') ||
                c == '_'))
                throw new IllegalArgumentException("CW09 " + __identifier);
        }
        
        // Is fine
        this.identifier = __identifier;
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public int compareTo(CIdentifier __b)
    {
        return this.identifier.compareTo(__b.identifier);
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public boolean equals(Object __o)
    {
        if (__o == this)
            return true;
        if (!(__o instanceof CIdentifier))
            return false;
        
        return this.identifier.equals(((CIdentifier)__o).identifier);
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public int hashCode()
    {
        return this.identifier.hashCode();
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/04
     */
    @Override
    public String toString()
    {
        return this.identifier;
    }
    
    /**
     * {@inheritDoc}
     * @since 2023/06/11
     */
    @Override
    public List<String> tokens()
    {
        return UnmodifiableList.of(Arrays.asList(this.identifier));
    }
    
    /**
     * Initializes the C identifier.
     * 
     * @param __identifier The C identifier.
     * @throws IllegalArgumentException If the identifier contains invalid
     * characters.
     * @throws NullPointerException On null arguments.
     * @since 2023/06/04
     */
    public static CIdentifier of(String __identifier)
        throws IllegalArgumentException, NullPointerException
    {
        return new CIdentifier(__identifier);
    }
}