Apple-2-Tools/dmolony-DiskBrowser
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ON GOSUB, ON GOTO

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This commit is contained in:
Denis Molony 2020-12-24 16:25:40 +10:00
parent 1e27aafde0
commit 331cff059f
1 changed files with 63 additions and 3 deletions
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66
src/com/bytezone/diskbrowser/applefile/ApplesoftBasicProgram.java
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@ -23,6 +23,7 @@ public class ApplesoftBasicProgram extends BasicProgram
private static final byte TOKEN_GOSUB = (byte) 0xB0;
private static final byte TOKEN_RETURN = (byte) 0xB1;
private static final byte TOKEN_REM = (byte) 0xB2;
private static final byte TOKEN_ON = (byte) 0xB4;
private static final byte TOKEN_PRINT = (byte) 0xBA;
private static final byte TOKEN_THEN = (byte) 0xC4;
private static final byte TOKEN_EQUALS = (byte) 0xD0;
@ -688,6 +689,7 @@ public class ApplesoftBasicProgram extends BasicProgram
int length;
String[] nextVariables;
String forVariable = "";
String onExpression = "";
int assignEqualPos; // used for aligning the equals sign
SubLine (SourceLine parent, int startPtr, int length)
@ -730,6 +732,39 @@ public class ApplesoftBasicProgram extends BasicProgram
targetLine = getLineNumber (buffer, startPtr + 1);
addXref (targetLine, gosubLines);
break;
case TOKEN_ON:
p = startPtr + 1;
int max = startPtr + length - 1;
while (p < max && buffer[p] != TOKEN_GOTO && buffer[p] != TOKEN_GOSUB)
{
if (isHighBitSet (buffer[p]))
{
int val = buffer[p] & 0x7F;
if (val < ApplesoftConstants.tokens.length)
onExpression += " " + ApplesoftConstants.tokens[val];
}
else
onExpression += (char) (buffer[p]);
p++;
}
// System.out.println (onExpression); // may contain symbols +,- etc
switch (buffer[p++])
{
case TOKEN_GOSUB:
for (int destLine : getLineNumbers (buffer, p))
addXref (destLine, gosubLines);
break;
case TOKEN_GOTO:
for (int destLine : getLineNumbers (buffer, p))
addXref (destLine, gotoLines);
break;
default:
System.out.println ("GOTO / GOSUB not found");
}
break;
}
}
else
@ -744,12 +779,37 @@ public class ApplesoftBasicProgram extends BasicProgram
}
}
private int getLineNumber (byte[] buffer, int offset)
private List<Integer> getLineNumbers (byte[] buffer, int ptr)
{
List<Integer> lineNumbers = new ArrayList<> ();
int start = ptr;
while (ptr < buffer.length && buffer[ptr] != 0 && buffer[ptr] != ASCII_COLON)
ptr++;
String s = new String (buffer, start, ptr - start);
String[] chunks = s.split (",");
try
{
for (String chunk : chunks)
lineNumbers.add (Integer.parseInt (chunk));
}
catch (NumberFormatException e)
{
System.out.printf ("NFE: %s%n", s);
}
return lineNumbers;
}
private int getLineNumber (byte[] buffer, int ptr)
{
int lineNumber = 0;
while (offset < buffer.length)
while (ptr < buffer.length)
{
int b = (buffer[offset++] & 0xFF) - 0x30;
int b = (buffer[ptr++] & 0xFF) - 0x30;
if (b < 0 || b > 9)
break;
lineNumber = lineNumber * 10 + b;