InstrLoad.java

/*
 * Copyright (C) 2011 René Jeschke <rene_jeschke@yahoo.de>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.github.rjeschke.weel;

class InstrLoad implements Instr
{
    Value value;
    
    public InstrLoad()
    {
        this.value = new Value();
    }
    
    public InstrLoad(final double v)
    {
        this.value = new Value(v);
    }
    
    public InstrLoad(final String v)
    {
        this.value = new Value(v);
    }
    
    /** @see Instr#getType() */
    @Override
    public Op getType()
    {
        return Op.LOAD;
    }

    /** @see java.lang.Object#toString() */
    @Override
    public String toString()
    {
        return "LOAD " + escape(this.value.toString());
    }

    /** @see Instr#write(JvmMethodWriter) */
    @Override
    public void write(JvmMethodWriter mw)
    {
        mw.aload(0);
        switch(this.value.getType())
        {
        case NULL:
            mw.invokeVirtual("com.github.rjeschke.weel.WeelRuntime", "load", "()V");
            break;
        case STRING:
            mw.ldc(this.value.getString());
            mw.invokeVirtual("com.github.rjeschke.weel.WeelRuntime", "load", "(Ljava/lang/String;)V");
            break;
        case NUMBER:
        {
            final double val = this.value.getNumber(); 
            final int iVal = (int) val;
            if (iVal == val)
            {
                mw.ldc(iVal);
                mw.invokeVirtual("com.github.rjeschke.weel.WeelRuntime", "load", "(I)V");
            }
            else
            {
                final float check = (float) val;
                if (Double.compare(check, val) == 0)
                {
                    mw.ldc(check);
                    mw.invokeVirtual("com.github.rjeschke.weel.WeelRuntime", "load", "(F)V");
                }
                else
                {
                    mw.ldc(val);
                    mw.invokeVirtual("com.github.rjeschke.weel.WeelRuntime", "load", "(D)V");
                }
            }
            break;
        }
        default:
            throw new WeelException("Illegal value: " + this.value);
        }
    }
    
    public final static String escape(final String input)
    {
        final StringBuilder sb = new StringBuilder(input.length());
        for(int i = 0; i < input.length(); i++)
        {
            final char c = input.charAt(i);
            switch(c)
            {
            case '\n':
                sb.append("\\n");
                break;
            case '\r':
                sb.append("\\r");
                break;
            case '\t':
                sb.append("\\t");
                break;
            default:
                sb.append(c);
            }
        }
        return sb.toString();
    }
}