mirror of
https://github.com/michaelcmartin/Ophis.git
synced 2024-06-27 10:29:31 +00:00
198 lines
3.0 KiB
HTML
198 lines
3.0 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/loose.dtd">
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<HTML
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><HEAD
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><TITLE
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>Anonymous labels</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
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REL="HOME"
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TITLE="Programming with Ophis"
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HREF="book1.html"><LINK
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REL="UP"
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TITLE="Labels and aliases"
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HREF="c236.html"><LINK
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REL="PREVIOUS"
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TITLE="Labels and aliases"
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HREF="c236.html"><LINK
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REL="NEXT"
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TITLE="Aliasing"
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HREF="x262.html"></HEAD
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><BODY
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CLASS="SECTION"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Programming with Ophis</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="c236.html"
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ACCESSKEY="P"
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><<< Previous</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Labels and aliases</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="x262.html"
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ACCESSKEY="N"
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>Next >>></A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="SECTION"
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><H1
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CLASS="SECTION"
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><A
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NAME="AEN251"
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>Anonymous labels</A
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></H1
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><P
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> Anonymous labels are a way to handle short-ranged branches
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without having to come up with names for the then and else
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branches, for brief loops, and other such purposes. To define
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an anonymous label, use an asterisk. To refer to an anonymous
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label, use a series of <TT
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CLASS="LITERAL"
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>+</TT
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>
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or <TT
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CLASS="LITERAL"
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>-</TT
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> signs. <TT
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CLASS="LITERAL"
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>+</TT
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> refers to
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the next anonymous label, <TT
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CLASS="LITERAL"
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>++</TT
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> the label
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after that, etc. Likewise, <TT
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CLASS="LITERAL"
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>-</TT
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> is the most
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recently defined label, <TT
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CLASS="LITERAL"
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>--</TT
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> the one before
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that, and so on. The main body of the Hello World program
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with anonymous labels would be:
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</P
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><TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><PRE
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CLASS="PROGRAMLISTING"
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> ldx #0
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* lda hello, x
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beq +
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jsr $ffd2
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inx
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bne -
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* rts</PRE
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></TD
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></TR
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></TABLE
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><P
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> It is worth noting that anonymous labels are globally available.
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They are not temporary labels, and they ignore scoping
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restrictions.
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</P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="c236.html"
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ACCESSKEY="P"
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><<< Previous</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="book1.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="x262.html"
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ACCESSKEY="N"
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>Next >>></A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Labels and aliases</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="c236.html"
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ACCESSKEY="U"
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>Up</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>Aliasing</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |