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<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></A>

<UL CLASS="ChildLinks">
<LI><A NAME="tex2html790"
  HREF="node21.html#SECTION002110000000000000000">Variables</A>
<UL>
<LI><A NAME="tex2html791"
  HREF="node21.html#SECTION002111000000000000000">Set</A>
<LI><A NAME="tex2html792"
  HREF="node21.html#SECTION002112000000000000000">NewSet</A>
<LI><A NAME="tex2html793"
  HREF="node21.html#SECTION002113000000000000000">Mset</A>
<LI><A NAME="tex2html794"
  HREF="node21.html#SECTION002114000000000000000">RndSet</A>
<LI><A NAME="tex2html795"
  HREF="node21.html#SECTION002115000000000000000">UnSet VariableName</A>
<LI><A NAME="tex2html796"
  HREF="node21.html#SECTION002116000000000000000">ShowVars</A>
<LI><A NAME="tex2html797"
  HREF="node21.html#SECTION002117000000000000000">Inc and Dec</A>
<LI><A NAME="tex2html798"
  HREF="node21.html#SECTION002118000000000000000">VExpand On or Off</A>
<LI><A NAME="tex2html799"
  HREF="node21.html#SECTION002119000000000000000">StackValue</A>
</UL>
<BR>
<LI><A NAME="tex2html800"
  HREF="node21.html#SECTION002120000000000000000">Predefined Variables</A>
<LI><A NAME="tex2html801"
  HREF="node21.html#SECTION002130000000000000000">Indexing and Slicing</A>
<LI><A NAME="tex2html802"
  HREF="node21.html#SECTION002140000000000000000">Mathematical Expressions</A>
<LI><A NAME="tex2html803"
  HREF="node21.html#SECTION002150000000000000000">Conditionals</A>
<LI><A NAME="tex2html804"
  HREF="node21.html#SECTION002160000000000000000">Goto</A>
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<HR>

<H1><A NAME="SECTION002100000000000000000"></A>
<A NAME="sec-variables"></A>
<BR>
Variables, Conditionals and Jumps
</H1>

<P>
To make the processing of your music easier, 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  supports a very
primitive set for variable manipulations along with some conditional
testing and the oft-frowned-upon <SMALL>GOTO</SMALL> command.

<P>

<H1><A NAME="SECTION002110000000000000000">
Variables</A>
</H1>

<P>

<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  lets you set a variable, much like in other programming
languages and to do some basic manipulations on them. Variables are
most likely to be used for two reasons:

<P>

<UL>
<LI>For use in setting up conditional segments of your file,

<P>
</LI>
<LI>As a shortcut to entering complex chord sequences.

<P>
</LI>
</UL>

<P>
To begin, the following list shows the available commands to set and
manipulate variables:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set VariableName <SPAN  CLASS="textit">String</SPAN> 
<BR>
Mset VariableName ...MsetEnd 
<BR>
UnSet VariableName 
<BR>
ShowVars 
<BR>
Inc Variablename [value] 
<BR>
Dec Variablename [value] 
<BR>
Vexpand ON/Off   </B> 
   
	    </td></tr>
      </Table>

<P>
All variable names are case-insensitive. Any characters can be used in
a variable name. The only exceptions are that a variable name cannot
start with a ``$'' or a ``_'' (an underscore--this is reserved for
internal variables, see below) <SPAN  CLASS="textit">and</SPAN> names cannot contain a
``['' or ``]'' character (brace characters are reserved for
indexing, <A HREF="#slicing">details here</A>).

<P>
Variables are set and manipulated by using their names. Variables are
expanded when their name is prefaced by a space followed by single
``$'' sign. For example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set Silly Am / Bm / 
<BR>
1 $Silly   </B> 
   
	    </td></tr>
      </Table>

<P>
The first line creates the variable ``Silly''; the second creates a
bar of music with the chords ``Am / Bm /''.

<P>
<SPAN  CLASS="textit">Note that the ``$'' must be the first item on a line or follow a
space character. The variable name must be terminated by a space or
the end of a line.</SPAN> For example, the following will NOT work:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set Silly 4a;b;c;d; 
<BR>
1 Am {$Silly }   // needs space before the $  </B> 
   
	    </td></tr>
      </Table>

<P>
Nor will:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>1 Am { $Silly}  // needs space at the end of the name  </B> 
   
	    </td></tr>
      </Table>

<P>
However:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>1 Am { $Silly }   </B> 
   
	    </td></tr>
      </Table>

<P>
will work fine.

<P>
Following are details on all the available variable commands:

<P>

<H2><A NAME="SECTION002111000000000000000">
Set</A>
</H2>

<P>
Set or create a variable. You can skip the <SPAN  CLASS="textit">String</SPAN> if you do
want to assign an empty string to the variable. A valid example is:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set PassCount 1  </B> 
   
	    </td></tr>
      </Table>

<P>
You can concatenate variables or constants by using a single ``+''.
For example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Groove Rhumba 
<BR>
Repeat 
<BR>  ...
<BR>
Set a $_Groove + Sus 
<BR>
Groove $a 
<BR>  ...
<BR>
Groove Rhumba1 
<BR>
Repeatend   </B> 
   
	    </td></tr>
      </Table>

<P>
This can be useful in calling G<SMALL>ROOVE</SMALL> variations.

<P>

<H2><A NAME="SECTION002112000000000000000">
NewSet</A>
</H2>

<P>
The N<SMALL>EW</SMALL>S<SMALL>ET</SMALL> command works the same as S<SMALL>ET</SMALL> with the
exception that that it is completely ignored if the variable already
exists. So,

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>NewSet ChordVoice JazzGuitar   </B> 
   
	    </td></tr>
      </Table>

<P>
and

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If NDef ChordVoice
<BR>
Set ChordVoice JazzGuitar
<BR>
Endif  </B> 
   
	    </td></tr>
      </Table>

<P>
have identical results.

<P>

<H2><A NAME="SECTION002113000000000000000"></A> <A NAME="sec-mset"></A>
<BR>
Mset
</H2>     

<P>
This command is quite similar to S<SMALL>ET</SMALL>, but M<SMALL>SET</SMALL> expects
multiple lines. An example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>MSet LongVar 
<BR>
1 Cm 
<BR>
2 Gm 
<BR>
3 G7 
<BR>
MsetEnd   </B> 
   
	    </td></tr>
      </Table>

<P>
It is quite possible to set a variable to hold an entire section of
music (perhaps a chorus) and insert this via macro expansion at
various places in your file.

<P>
Each M<SMALL>SET</SMALL> must be terminated by a E<SMALL>ND</SMALL>M<SMALL>SET</SMALL> or
M<SMALL>SET</SMALL>E<SMALL>ND</SMALL> command (on its own separate line).

<P>
Be careful if you use an MS<SMALL>ET</SMALL> variable in a P<SMALL>RINT</SMALL>
statement ... you'll probably get an error. The P<SMALL>RINT</SMALL>
command will print the <SPAN  CLASS="textit">first</SPAN> line of the variable and the
remainder will be reinserted into the input stream for interpretation.

<P>
Variables are <SPAN  CLASS="textit">not</SPAN> expanded when creating an M<SMALL>SET</SMALL>
macro (lines are read verbatim from the input path)--this makes
M<SMALL>SET</SMALL> subtly different from S<SMALL>ET</SMALL>. Variables <SPAN  CLASS="textit">are</SPAN>
expanded when the macro is executed.

<P>
Special code in 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  will maintain the block settings from
B<SMALL>EGIN</SMALL>/E<SMALL>ND</SMALL>. So, you can do something like:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Mset Spam 
<BR>&nbsp;&nbsp;Line one 
<BR>&nbsp;&nbsp;Line 2 
<BR>&nbsp;&nbsp;333 
<BR>
EndMset 
<BR>
Begin Print 
<BR>&nbsp;&nbsp;$Spam 
<BR>
End   </B> 
   
	    </td></tr>
      </Table>

<P>

<H2><A NAME="SECTION002114000000000000000"></A>

<A NAME="rndset"></A>
<BR>
RndSet
</H2>

<P>
There are times when you may want a random value to use in selecting a
G<SMALL>ROOVE</SMALL> or for other more creative purposes. The R<SMALL>ND</SMALL>S<SMALL>ET</SMALL>
command sets a variable from a value in a list. The list can be
anything; just remember that each white space forms the start of a new
item. So,

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>RndSet Var 1 2 3 4 5  </B> 
   
	    </td></tr>
      </Table>

<P>
will set $V<SMALL>AR</SMALL> to one of the values 1, 2, 3, 4 or 5.

<P>
You could use this to randomly select a G<SMALL>ROOVE</SMALL>:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Groove $var Groove1 Groove2 Groove3  </B> 
   
	    </td></tr>
      </Table>

<P>
Alternately,

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>RndSet Grv Groove1 Groove2 Groove3  </B> 
   
	    </td></tr>
      </Table>

<P>
will set $G<SMALL>RV</SMALL> to one of ``Groove1'', ``Groove2'' or
``Groove3''.

<P>
Then you can do the same as in the earlier example with:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Groove $Grv  </B> 
   
	    </td></tr>
      </Table>

<P>
You can also have fun using random values for timing, transposition,
etc.

<P>

<H2><A NAME="SECTION002115000000000000000">
UnSet VariableName</A>
</H2>

<P>
Removes the variable. This can be useful if you have conditional tests
which simply rely on a certain variable being ``defined''.

<P>

<H2><A NAME="SECTION002116000000000000000">
ShowVars</A>
</H2>

<P>
Mainly used for debugging, this command displays the names of the
defined variables and their contents.  The display will preface each
variable name with a ``$''. Note that internal 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  variables are
not displayed with this command.

<P>
You can call S<SMALL>HOW</SMALL>V<SMALL>ARS</SMALL> with an argument list. In this case the
values of the variables names in the list will be printed. Variables
which do not exist will <SPAN  CLASS="textit">not</SPAN> cause an error, e.g.:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>ShowVars xXx Count foo 
<BR>&nbsp;&nbsp;&nbsp;$XXX - not defined 
<BR>&nbsp;&nbsp;&nbsp;$COUNT: 11 
<BR>&nbsp;&nbsp;&nbsp;$FOO: This is Foo   </B> 
   
	    </td></tr>
      </Table>

<P>

<H2><A NAME="SECTION002117000000000000000">
Inc and Dec</A>
</H2>

<P>
These commands increment or decrement a variable. If no argument is
given, a value of 1 is used; otherwise, the value specified is used.
The value can be an integer or a floating point number.

<P>
A short example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set PassCount 1 
<BR>
Set Foobar 4 
<BR>
Showvars 
<BR>
Inc FooBar 4 
<BR>
Inc PassCount 
<BR>
ShowVars   </B> 
   
	    </td></tr>
      </Table>

<P>
This command is quite useful for creating conditional tests for proper
handling of codas or groove changes in repeats.

<P>

<H2><A NAME="SECTION002118000000000000000">
VExpand On or Off</A>
</H2>

<P>
Normally variable expansion is enabled. These two options will turn
expansion on or off. Why would you want to do this? Well, here's a
simple example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set LeftC Am Em 
<BR>
Set RightC G / 
<BR>
VExpand Off 
<BR>
Set Full $LeftC $RightC 
<BR>
VExpand On   </B> 
   
	    </td></tr>
      </Table>

<P>
In this case the actual contents of the variable ``Full'' is ``$LeftC
$RightC''. If the O<SMALL>FF/</SMALL>O<SMALL>N</SMALL> option lines had not been used, the
contents would be ``Am Em G /''. You can easily verify this with the
S<SMALL>HOW</SMALL>V<SMALL>ARS</SMALL> option.

<P>
When 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  processes a file it expands variables in a recursive
manner. This means that, in the above example, the line:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>1 $Full  </B> 
   
	    </td></tr>
      </Table>

<P>
will be changed to:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>1 Am Em G /  </B> 
   
	    </td></tr>
      </Table>

<P>
However, if later in the file, you change the definition of one of the
variables ... for example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set LeftC Am /  </B> 
   
	    </td></tr>
      </Table>

<P>
the same line will now be ``1 Am / G /''.

<P>
Most of 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT> 's internal commands <SPAN  CLASS="textit">can</SPAN> be redefined with
variables. However, you really shouldn't use this feature.  It's been
left for two reasons: it might be useful, and, it's hard to disable.

<P>
Not all commands can be redefined. The following examples will work,
however <SPAN  CLASS="textit">in most cases we
recommend that you do not redefine 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  commands</SPAN>.

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set Rate Tempo 120 
<BR>  $Rate 
<BR>
Set  R Repeat 
<BR>  $R   </B> 
   
	    </td></tr>
      </Table>

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set B Begin 
<BR>
Set  E End 
<BR>  $B Arpeggio Define 
<BR>  ...
<BR>  $E   </B> 
   
	    </td></tr>
      </Table>

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set A Define Arpeggio 
<BR>
Begin 
<BR>  $a ...
<BR>
End   </B> 
   
	    </td></tr>
      </Table>

<P>
Even though you can use a variable to substitute for the R<SMALL>EPEAT</SMALL>
or I<SMALL>F</SMALL> directives, using one for R<SMALL>EPEAT</SMALL>E<SMALL>ND</SMALL>,
E<SMALL>ND</SMALL>R<SMALL>EPEAT</SMALL>, R<SMALL>EPEAT</SMALL>E<SMALL>NDING</SMALL>, L<SMALL>ABEL</SMALL>, I<SMALL>F</SMALL>E<SMALL>ND</SMALL> or
E<SMALL>ND</SMALL>I<SMALL>F</SMALL> will fail.

<P>
Variable expansion should usually not be a concern. In most normal
files, 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  will expand variables as they are encountered. However,
when reading the data in a R<SMALL>EPEAT</SMALL>, I<SMALL>F</SMALL> or M<SMALL>SET</SMALL>
section the expansion function is skipped--but, when the lines are
processed, after being stored in an internal queue, variables are
expanded.

<P>
V<SMALL>EXPAND</SMALL> only has an effect when creating a macro using
S<SMALL>ET</SMALL>. It has <SPAN  CLASS="textit">no</SPAN> effect when using M<SMALL>SET</SMALL>.

<P>

<H2><A NAME="SECTION002119000000000000000"></A>
<A NAME="stackvalue"></A>
<BR>
StackValue
</H2>

<P>
Sometimes you just want to save a value for a few lines of code. The
S<SMALL>TACK</SMALL>V<SMALL>ALUE</SMALL> command will save its arguments. You can later
retrieve them via the $_StackValue macro. For example (taken from
the <TT><SPAN  CLASS="textbf">stdpats.mma</SPAN></TT> file):

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>StackValue $_SwingMode 
<BR>
SwingMode On 
<BR>
Begin Drum Define 
<BR>&nbsp;&nbsp;Swing8 1 0 90 * 8 
<BR>
End 
<BR>&nbsp;&nbsp;...
<BR>
SwingMode $_StackValue   </B> 
   
	    </td></tr>
      </Table>

<P>
Note that the $_StackValue macro removes the last value from the
stack. If you invoke the macro when there is nothing saved an error
will occur.

<P>

<H1><A NAME="SECTION002120000000000000000"></A>
<A NAME="sec-sysvariables"></A>
<BR>
Predefined Variables
</H1>

<P>
For your convenience 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  tracks a number of internal settings and
you can access these values with special macros.<A NAME="tex2html81"
  HREF="#foot11484"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">1</SPAN></SUP></A>  All of these ``system'' variables are
prefaced with a single underscore. For example, the current tempo is
displayed with the variable $_TEMPO.

<P>
There are two categories of system variables. The first are the simple
values for global settings:

<P>
<DL>
<DT><STRONG>&nbsp;&nbsp;$_AutoLibPath</STRONG></DT>
<DD>Current A<SMALL>UTO</SMALL>L<SMALL>IB</SMALL>P<SMALL>ATH</SMALL> setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_BarNum</STRONG></DT>
<DD>Current bar number of song.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_ChordAdjust</STRONG></DT>
<DD>The chord adjustment table values
  <A HREF="node14.html#sec-chordadjust">(see here)</A>. Note,
  you cannot use this value to reset the table.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_CTabs</STRONG></DT>
<DD>List of the time-set chord tabs.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Debug</STRONG></DT>
<DD>Current debug settings.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Groove</STRONG></DT>
<DD>Name of the currently selected groove. May be
  empty if no groove has been selected.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Groovelist</STRONG></DT>
<DD>List of all currently defined G<SMALL>ROOVE</SMALL> names.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_KeySig</STRONG></DT>
<DD>Key signature as defined in song file. If no key
  signature is set the somewhat cryptic 0# will be returned.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_IncPath</STRONG></DT>
<DD>Current I<SMALL>NC</SMALL>P<SMALL>ATH</SMALL> setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_LastDebug</STRONG></DT>
<DD>Debug settings prior to last D<SMALL>EBUG</SMALL>
  command. This setting can be used to restore settings, e.g.:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Debug Warnings=off 
<BR>    ...stuff generating annoying warnings
<BR>
Debug $_LastDebug   </B> 
   
	    </td></tr>
      </Table>

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_LastGroove</STRONG></DT>
<DD>Name of the groove selected <SPAN  CLASS="textit">before</SPAN> the
  currently selected groove.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_LastVolume</STRONG></DT>
<DD>Previously set global volume setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_LibPath</STRONG></DT>
<DD>Current L<SMALL>IB</SMALL>P<SMALL>ATH</SMALL> setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_LineNum</STRONG></DT>
<DD>Line number in current file.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Lyric</STRONG></DT>
<DD>Current L<SMALL>YRIC</SMALL> settings.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_MMAPath</STRONG></DT>
<DD>The root directory used by 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT> . The modules,
  library, etc. are in this directory. This is set at startup and
  cannot be modified by the user.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_MIDISplit</STRONG></DT>
<DD>List of S<SMALL>PLIT</SMALL>C<SMALL>HANNELS</SMALL>.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_MIDIPlayer</STRONG></DT>
<DD>Current M<SMALL>IDI</SMALL>P<SMALL>LAYER</SMALL> setting, including options.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_NoteLen(n)</STRONG></DT>
<DD>Returns value of the duration in MIDI ticks of
  ``n''. Note: No spaces are permitted. Examples:
    
      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>$_NoteLen(8.)  </B> 
   
	    </td></tr>
      </Table>

  returns 144T, the duration of a dotted eight note,
    
      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>$_NoteLen(5:4+16)  </B> 
   
	    </td></tr>
      </Table>

   returns 86T, the duration of a 5:4 tuplet plus a 16th.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_OutPath</STRONG></DT>
<DD>Current O<SMALL>UT</SMALL>P<SMALL>ATH</SMALL> setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Plugins</STRONG></DT>
<DD>A list of registered simple plugins.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Seq</STRONG></DT>
<DD>Current S<SMALL>EQ</SMALL> point (0 to
  S<SMALL>EQ</SMALL>S<SMALL>IZE</SMALL>). Useful in debugging.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_SeqRnd</STRONG></DT>
<DD>Global S<SMALL>EQ</SMALL>R<SMALL>ND</SMALL> setting (on, off or track
  list).

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_SeqRndWeight</STRONG></DT>
<DD>Global S<SMALL>EQ</SMALL>R<SMALL>ND</SMALL>W<SMALL>EIGHT</SMALL> settings.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_SeqSize</STRONG></DT>
<DD>Current S<SMALL>EQ</SMALL>S<SMALL>IZE</SMALL> setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_SwingMode</STRONG></DT>
<DD>Current S<SMALL>WING</SMALL>M<SMALL>ODE</SMALL> setting (On or Off)
  and the Skew value.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_StackValue</STRONG></DT>
<DD>The last value stored on the S<SMALL>TACK</SMALL>V<SMALL>ALUE</SMALL>
  stack.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Tempo</STRONG></DT>
<DD>Current T<SMALL>EMPO</SMALL>. Note that if you have used
  the optional <SPAN  CLASS="textit">bar count</SPAN> in setting the tempo this will be the
  target tempo.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TickPos</STRONG></DT>
<DD>Helpful in debugging, this variable is set to the
  current tick position in the generated MIDI file.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Time</STRONG></DT>
<DD>The current T<SMALL>IME</SMALL> (beats per bar) setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TimeSig</STRONG></DT>
<DD>The last value set for TimeSig.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_ToneTr</STRONG></DT>
<DD>List of all T<SMALL>ONE</SMALL>TR settings.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Tracklist</STRONG></DT>
<DD>List of all currently defined T<SMALL>RACK</SMALL> names.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Transpose</STRONG></DT>
<DD>Current T<SMALL>RANSPOSE</SMALL> setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_VExpand</STRONG></DT>
<DD>VExpand value (On/Off). Not very useful since you
  can't enable VEXPAND back with a macro.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_VoiceTr</STRONG></DT>
<DD>List of all V<SMALL>OICE</SMALL>TR settings.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_Volume</STRONG></DT>
<DD>Current global volume setting.

<P>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_VolumeRatio</STRONG></DT>
<DD>Global volume ratio (track vrs. master) from
  A<SMALL>DJUST</SMALL>V<SMALL>OLUME</SMALL> Ratio setting.

<P>
</DD>
</DL>

<P>
The second type of system variable is for settings in a certain track.
Each of these variables is in the form $_TRACKNAME_VALUE. For
example, the current voice setting for the ``Bass-Sus'' track can be
accessed with the variable $_Bass-Sus_Voice.

<P>
If the associated command permits a value for each sequence in your
pattern, the macro will more than one value. For example (assuming a
S<SMALL>EQ</SMALL>S<SMALL>IZE</SMALL> of 4):

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Bass Octave 3 4 2 4 
<BR>
Print $_Bass_Octave  
<BR>  ...
<BR>
3 4 2 4   </B> 
   
	    </td></tr>
      </Table>

<P>
The following are the available ``TrackName'' macros:

<P>
<DL>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Accent</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Articulate</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Channel</STRONG></DT>
<DD>Assigned MIDI channel 1-16, 0 if not
  assigned.
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Compress</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Delay</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Direction</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_DupRoot</STRONG></DT>
<DD>(only permitted in Chord Tracks)
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Harmony</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_HarmonyOnly</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_HarmonyVolume</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Invert</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Limit</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Mallet</STRONG></DT>
<DD>Rate and delay values (only valid in
  Solo and Melody tracks)
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_MidiNote</STRONG></DT>
<DD>Current setting
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_MOctave</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_MIDIVolume</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_NoteSpan</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Octave</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Ornament</STRONG></DT>
<DD>(all options)
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Plugins</STRONG></DT>
<DD>(track registered plugins, the same for all tracks)
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Range</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_RDuration</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Rpitch</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Rskip</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Rtime</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Rvolume</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_SeqRnd</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_SeqRndWeight</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Sequence</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Span</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Sticky</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Strum</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_StrumAdd</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Tone</STRONG></DT>
<DD>(only permitted in Drum tracks)
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Trigger</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Unify</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Voice</STRONG></DT>
<DD>
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Voicing</STRONG></DT>
<DD>(only permitted in Chord tracks)
</DD>
<DT><STRONG>&nbsp;&nbsp;$_TRACKNAME_Volume</STRONG></DT>
<DD><P>
</DD>
</DL>

<P>
The ``TrackName'' macros are useful in copying values between
non-similar tracks and C<SMALL>H</SMALL>S<SMALL>HARE</SMALL> tracks. For example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Begin Bass
<BR>&nbsp;&nbsp;Voice AcousticBass  
<BR>&nbsp;&nbsp;Octave 3    
<BR>&nbsp;&nbsp;...
<BR>
End
<BR>
Begin Walk
<BR>&nbsp;&nbsp;ChShare Bass
<BR>&nbsp;&nbsp;Voice $_Bass_Voice
<BR>&nbsp;&nbsp;Octave $_Bass_Octave
<BR>&nbsp;&nbsp;...
<BR>
End  </B> 
   
	    </td></tr>
      </Table>

<P>

<H1><A NAME="SECTION002130000000000000000"></A>
 <A NAME="slicing"></A>
<BR>
Indexing and Slicing
</H1>

<P>
All variables can have an option <SPAN  CLASS="textit">slice</SPAN> or <SPAN  CLASS="textit">index</SPAN> appended
to them using ``[]'' notation. The exact syntax of the data in the
``[]''s is dependent on the underlying Python interpreter. But, as a
summary:

<P>
<DL COMPACT>
<DT></DT>
<DD><SPAN  CLASS="textbf">[2]</SPAN> - selects the 3rd item in the list,
</DD>
<DT></DT>
<DD><SPAN  CLASS="textbf">[1:2]</SPAN> - selects the 2nd to 3rd item (which means only the
  2nd),
</DD>
<DT></DT>
<DD><SPAN  CLASS="textbf">[0:2]</SPAN> - selects items 1 and 2,
</DD>
<DT></DT>
<DD><SPAN  CLASS="textbf">[-1]</SPAN> - selects the last item.
</DD>
</DL>

<P>
It is possible to use the <SPAN  CLASS="textit">step</SPAN> option as well, but we don't
know when you would.

<P>
When indexing or slicing a variable, the following should be kept in
mind:

<P>

<UL>
<LI>For simple variables which contain only one element
  (e.g., $_Tempo) any index other than ``[0]'', ``[-1]'', etc. will
  return an empty string.

<P>
</LI>
<LI>Variables containing multiple values (e.g., $_Bass_Volume) are
  treated as list. Slicing and indexing is useful to extract a single
  value.

<P>
</LI>
<LI>Variables created with M<SMALL>SET</SMALL> are treated a list of
  lines. Slicing returns multiple (or single) lines. This can be
  useful in selecting only a portion of a previously created variable.

<P>
</LI>
</UL>
The ``[]'' must follow the variable <SPAN  CLASS="textit">without</SPAN> any space
characters. The expression inside the ``[]'' must not contain any
spaces.

<P>
The index or slice expression cannot be a variable.

<P>
An example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Groove bossanova 
<BR>
Bass Volume m mf p mp 
<BR>
print $_Bass_Volume 
<BR>
print $_Bass_Volume[1:3] 
<BR>
print $_Bass_volume[2]   </B> 
   
	    </td></tr>
      </Table>

<P>
will display:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>100 110 40 70 
<BR>
110 40 
<BR>
40   </B> 
   
	    </td></tr>
      </Table>

<P>

<H1><A NAME="SECTION002140000000000000000">
Mathematical Expressions</A>
</H1>

<P>
Anywhere you can use a variable (user defined or built-in) you can
also use a mathematical expression. Expressions delimited in a
$(...) set are passed to the underlying Python interpreter, parsed
and expanded. Included in an expression can be any combination of
values, operators, and 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  variables.

<P>
Here are a couple of examples with the 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  generated values:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Print  $( 123 * (4.0/5) ) 
<BR>
98.4   </B> 
   
	    </td></tr>
      </Table>

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Tempo 100 
<BR>
Set V $( $_Tempo + 44) 
<BR>
Print $v 
<BR>
144   </B> 
   
	    </td></tr>
      </Table>

<P>
How it works: 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  first parses each line and expands any variables
it finds. In the second example this means that the $_Tempo is
converted to ``100''. After all the variable expansion is done a check
is made to find math delimiters. Anything inside these delimiters is
evaluated by Python.

<P>
You can even use this feature to modify values stored in
lists.<A NAME="tex2html82"
  HREF="#foot11669"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">2</SPAN></SUP></A> A bit complex, but well worthwhile! In the following
example we add ``10'' to the current A<SMALL>RTICULATE</SMALL> setting. It's
split into three lines to make it clearer:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>set a $( ' $_Chord_Articulate '.split() )   </B> 
   
	    </td></tr>
      </Table>

<P>
Note the use of single quotes to convert the 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  ``string'' to
something Python can deal with. You could just as easily use double
quotes, but do note that the spaces before the ``$'' and before the
final `` ' '' are needed. The result of the above is that the variable
``$a'' now is set to something like: ``['100', '100', '90', '80']''.

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>set b $([str(int(x)+10)for x in $a ] )   </B> 
   
	    </td></tr>
      </Table>

<P>
Next we use a list comprehension to add ``10'' to each value in the
list. Our new list (contained in ``$b'') will be: ``['110', '110',
'100', '90']''. Notice how the strings were converted from strings to
integers (for the addition) and then back to strings.

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>set c $( ' '.join( $b ) )   </B> 
   
	    </td></tr>
      </Table>

<P>
The new list is now converted to a string which 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  can deal with
and store it in ``$c''. In this case: ``110 110 100 90''.

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Chord Articulate $c   </B> 
   
	    </td></tr>
      </Table>

<P>
Finally, C<SMALL>HORD</SMALL> A<SMALL>RTICULATE</SMALL> is modified.

<P>
Now, that that is clear, you can easily combine the operation using no
variables at all:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Chord Articulate $(' '.join([str(int(x)+10)for x in'
  $_Chord_Articulate '.split()]))   </B> 
   
	    </td></tr>
      </Table>

<P>
Some additional notes:

<P>

<UL>
<LI>To keep your computer safe from malicious scripts, only the
  following operators and functions are permitted.

<P>
The unary operators:

<P>
<PRE>
    - + ~
</PRE>

<P>
the basic operators:

<P>
<PRE>
    + - / // % * **
</PRE>

<P>
the bitwise operators:

<P>
<PRE>
    &amp; | ^ &lt;&lt; &gt;&gt;
</PRE>

<P>
the constants:

<P>
<PRE>
    e pi
</PRE>

<P>
the functions:

<P>
<PRE>
    ceil() fabs() floor() exp() log() log10() pow()
    sqrt() acos() asin()  atan() atan2() cos() hypot()
    sin()  tan()  degrees() radians() cosh() sinh()
    tanh() abs()  chr()  int()
</PRE>

<P>
the miscellaneous functions:<A NAME="tex2html83"
  HREF="#foot11578"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">3</SPAN></SUP></A>
<P>
<PRE>
    for, in, str(), .join(), .split()
</PRE>

<P>
and values and parentheses.

<P>
</LI>
<LI>For details on the use/format of the above please refer to the
  Python documentation.

<P>
</LI>
<LI>$(...) expressions cannot be nested.

<P>
</LI>
<LI>There must be a whitespace character before the leading $.

<P>
</LI>
<LI>Any 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  variables must be delimited with whitespace. For
  example $( $_Tempo + 44) will work; however, both $($_Tempo +
  44) and $( $_Tempo+ 44) will cause an error.

<P>
</LI>
<LI>The supplied file <TT><SPAN  CLASS="textbf">egs/misc/math.mma</SPAN></TT> shows a number of
  examples.

<P>
</LI>
</UL>

<P>

<H1><A NAME="SECTION002150000000000000000">
Conditionals</A>
</H1>

<P>
One of the most important reasons to have variables in 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  is to use
them in conditionals. In 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  a conditional consists of a line
starting with an I<SMALL>F</SMALL> directive, a test, a series of lines to
process (depending upon the result of the test), and a closing
E<SMALL>ND</SMALL>I<SMALL>F</SMALL> or I<SMALL>F</SMALL>E<SMALL>ND</SMALL><A NAME="tex2html84"
  HREF="#foot11670"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">4</SPAN></SUP></A>  directive. An optional E<SMALL>LSE</SMALL> statement may be included.

<P>
The first set of tests are unary (they take no arguments):

<P>
<DL>
<DT><STRONG>Def VariableName</STRONG></DT>
<DD>Returns true if the variable has been defined.

<P>
</DD>
<DT><STRONG>Ndef VariableName</STRONG></DT>
<DD>Returns true if the variable has not been
  defined.

<P>
</DD>
</DL>

<P>
In the above tests you must supply the name of a variable--don't make
the mistake of including a ``$'' which will invoke expansion and
result in something you were not expecting.

<P>
A simple example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If Def InCoda 
<BR>&nbsp;&nbsp;5 Cm 
<BR>&nbsp;&nbsp;6 / 
<BR>
Endif  </B> 
   
	    </td></tr>
      </Table>

<P>
The other tests are binary. Each test requires a conditional (symbolic
or mnemonic as detailed in the following table) and two arguments.

<P>
<TABLE CELLPADDING=3 BORDER="1">
<TR><TD ALIGN="CENTER">Mnemonic</TD>
<TD ALIGN="CENTER">Symbolic</TD>
<TD ALIGN="LEFT">Condition</TD>
</TR>
<TR><TD ALIGN="CENTER">&nbsp;</TD>
<TD ALIGN="CENTER">&nbsp;</TD>
<TD ALIGN="LEFT">&nbsp;</TD>
</TR>
<TR><TH ALIGN="CENTER"><SPAN  CLASS="textbf">LT</SPAN></TH>
<TD ALIGN="CENTER"><SPAN  CLASS="textbf">&lt;</SPAN></TD>
<TD ALIGN="LEFT">True if <SPAN  CLASS="textit">Str1</SPAN> is less than  <SPAN  CLASS="textit">Str2</SPAN></TD>
</TR>
<TR><TH ALIGN="CENTER"><SPAN  CLASS="textbf">LE</SPAN></TH>
<TD ALIGN="CENTER"><SPAN  CLASS="textbf">&lt;=</SPAN></TD>
<TD ALIGN="LEFT">True if <SPAN  CLASS="textit">Str1</SPAN> is less than or equal to
  <SPAN  CLASS="textit">Str2</SPAN></TD>
</TR>
<TR><TH ALIGN="CENTER"><SPAN  CLASS="textbf">EQ</SPAN></TH>
<TD ALIGN="CENTER"><SPAN  CLASS="textbf">==</SPAN></TD>
<TD ALIGN="LEFT">True if <SPAN  CLASS="textit">Str1</SPAN> is equal to   <SPAN  CLASS="textit">Str2</SPAN></TD>
</TR>
<TR><TH ALIGN="CENTER"><SPAN  CLASS="textbf">NE</SPAN></TH>
<TD ALIGN="CENTER"><SPAN  CLASS="textbf">!=</SPAN></TD>
<TD ALIGN="LEFT">True if <SPAN  CLASS="textit">Str1</SPAN> is not equal to   <SPAN  CLASS="textit">Str2</SPAN></TD>
</TR>
<TR><TH ALIGN="CENTER"><SPAN  CLASS="textbf">GT</SPAN></TH>
<TD ALIGN="CENTER"><SPAN  CLASS="textbf">&gt;</SPAN></TD>
<TD ALIGN="LEFT">True if <SPAN  CLASS="textit">Str1</SPAN> is greater than <SPAN  CLASS="textit">Str2</SPAN></TD>
</TR>
<TR><TH ALIGN="CENTER"><SPAN  CLASS="textbf">GE</SPAN></TH>
<TD ALIGN="CENTER"><SPAN  CLASS="textbf">&gt;=</SPAN></TD>
<TD ALIGN="LEFT">True if <SPAN  CLASS="textit">Str1</SPAN> is greater than or
  equal to <SPAN  CLASS="textit">Str2</SPAN></TD>
</TR>
</TABLE>

<P>
In the above tests you have several choices in specifying <SPAN  CLASS="textit">Str1</SPAN>
and <SPAN  CLASS="textit">Str2</SPAN>. At some point, when 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  does the actual comparison,
two strings or numeric values are expected. So, you really could do:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If EQ abc ABC  </B> 
   
	    </td></tr>
      </Table>

<P>
and get a ``true'' result. The reason that ``abc'' equals ``ABC'' is
that all the comparisons in 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  are case-insensitive.

<P>
You can also compare a variable to a string:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If &gt; $foo abc  </B> 
   
	    </td></tr>
      </Table>

<P>
will evaluate to ``true'' if the <SPAN  CLASS="textit">contents</SPAN> of the variable
``foo'' evaluates to something ``greater than'' ``abc''. But, there is
a bit of a ``gotcha'' here. If you have set ``foo'' to a two word
string, then 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  will choke on the command. In the following
example:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set Foo A B 
<BR>
If GT $Foo abc   </B> 
   
	    </td></tr>
      </Table>

<P>
the comparison is passed the line:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If GT A B abc  </B> 
   
	    </td></tr>
      </Table>

<P>
and 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  seeing three arguments generates an error. If you want the
comparison done on a variable which might be more than one word, use
the ``$$'' syntax. This delays the expansion of the variable until
the I<SMALL>F</SMALL> directive is entered. So:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If GT $$foo abc  </B> 
   
	    </td></tr>
      </Table>

<P>
would generate a comparison between ``A B'' and ``ABC''.

<P>
Delayed expansion can be applied to either variable. It only works in
an I<SMALL>F</SMALL> directive.

<P>
Strings and numeric values can be confusing in comparisons. For
example, if you have the strings ``22'' and ''3'' and compare them as
strings, ``3'' is greater than ``22''; however, if you compare them as
values then 3 is less than 22. The rule in 
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  is quite simple: If
both strings can be converted to a value, a numeric comparison is done;
otherwise they are compared as strings.<A NAME="tex2html85"
  HREF="#foot11641"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">5</SPAN></SUP></A>
<P>
This lets you do consistent comparisons in situations like:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Set Count 1 
<BR>
If LE $$Count 4 
<BR>&nbsp;&nbsp;...
<BR>
IfEnd  </B> 
   
	    </td></tr>
      </Table>

<P>
Note that the above example could have used ``$Count'', but you
should probably always use the ``$$'' in tests.

<P>
Much like other programming languages, an optional E<SMALL>LSE</SMALL>
condition may be used:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If Def Coda 
<BR>&nbsp;&nbsp;Groove Rhumba1 
<BR>
Else 
<BR>&nbsp;&nbsp;Groove Rhumba 
<BR>
Endif   </B> 
   
	    </td></tr>
      </Table>

<P>
The E<SMALL>LSE</SMALL> statement(s) are processed only if the test for the
I<SMALL>F</SMALL> test is false.

<P>
Nesting of I<SMALL>F</SMALL>s is permitted:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>If ndef Foo 
<BR>&nbsp;&nbsp;Print Foo has been defined. 
<BR>
Else 
<BR>&nbsp;&nbsp;If def bar 
<BR>&nbsp;&nbsp;&nbsp;&nbsp;Print bar has been defined. Cool. 
<BR>&nbsp;&nbsp;Else 
<BR>&nbsp;&nbsp;&nbsp;&nbsp;Print no bar ...go thirsty. 
<BR>&nbsp;&nbsp;Endif 
<BR>
Endif   </B> 
   
	    </td></tr>
      </Table>

<P>
works just fine. Indentation has been used in these examples to
clearly show the nesting and conditions. You should do the same.

<P>

<H1><A NAME="SECTION002160000000000000000">
Goto</A>
</H1>

<P>
The G<SMALL>OTO</SMALL> command redirects the execution order of your script
to the point at which a L<SMALL>ABEL</SMALL> or line number has been
defined. There are really two parts to this:

<P>

<OL>
<LI>A command defining a label, and,

<P>
</LI>
<LI>The G<SMALL>OTO</SMALL> command.

<P>
</LI>
</OL>

<P>

<P>
A label is set with the L<SMALL>ABEL</SMALL> directive:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Label Point1  </B> 
   
	    </td></tr>
      </Table>

<P>
The string defining the label can be any sequence of characters.
Labels are case-insensitive.

<P>
To make this look a lot more line those old BASIC programs, any lines
starting with a line number are considered to be label lines as well.

<P>
A few considerations on labels and line numbers:

<P>

<UL>
<LI>A duplicate label generated with a L<SMALL>ABEL</SMALL> command will
  generate an error.

<P>
</LI>
<LI>A line number label duplicating a L<SMALL>ABEL</SMALL> is an error.

<P>
</LI>
<LI>A L<SMALL>ABEL</SMALL> duplicating a line number is an error.

<P>
</LI>
<LI>Duplicate line numbers are permitted. The last one encountered
  will be the one used.

<P>
</LI>
<LI>All label points are generated when the file is opened, not as
  it is parsed.

<P>
</LI>
<LI>Line numbers (really, just comments) do not need to be in any
  order.

<P>
</LI>
</UL>

<P>

<P>
The command:

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Goto Point1  </B> 
   
	    </td></tr>
      </Table>

<P>
causes an immediate jump to a new point in the file. If you are
currently in repeat or conditional segment of the file, the remaining
lines in that segment will be ignored.

<P>

<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT>  does not check to see if you are jumping into a repeat or
conditional section of code--but doing so will usually cause an
error. Jumping out of these sections is usually safe.

<P>
The following example shows the use of both types of label. In this
example only lines 2, 3, 5 and 6 will be processed.

<P>

      <Table Hspace="40%" CellSpacing=0 CellPadding=10 BGColor="OldLace" Border=3>
        <tr><td>
    <B>Goto Foo 
<BR>
1 Cm 
<BR>
Label Foo 
<BR>
2 Dm 
<BR>
3 / 
<BR>
Goto 5 
<BR>
4 Am 
<BR>
5 Cm 
<BR>
6 Dm   </B> 
   
	    </td></tr>
      </Table>

<P>
For an example of how to use some simple labels to simulate a ``DS al
Coda'' examine the file ``lullaby-of-Broadway'' in the sample songs
directory.

<P>
<BR><HR><H4>Footnotes</H4>
<DL>
<DT><A NAME="foot11484">... macros.</A><A
 HREF="node21.html#tex2html81"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">1</SPAN></SUP></A></DT>
<DD>The values
  are dynamically created and reflect the current settings, and may
  not be exactly the same as the value you originally set due to
  internal roundings, etc.

</DD>
<DT><A NAME="foot11669">...
lists.</A><A
 HREF="node21.html#tex2html82"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">2</SPAN></SUP></A></DT>
<DD>this was written before the introduction of slices,
  (<A HREF="#slicing">details here</A>). Slices make this
  much easier, but lets leave the hard stuff in just to show what can
  be done.

</DD>
<DT><A NAME="foot11578">... functions:</A><A
 HREF="node21.html#tex2html83"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">3</SPAN></SUP></A></DT>
<DD>It is possible that the
    following functions could be used to do ``bad'' things. If you see
    code using these commands from a suspect source you should be
    careful.

</DD>
<DT><A NAME="foot11670">...I<SMALL>F</SMALL>E<SMALL>ND</SMALL></A><A
 HREF="node21.html#tex2html84"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">4</SPAN></SUP></A></DT>
<DD>
<FONT Face="Serif"  Color="Navy"><I>MMA</I></FONT> 's author probably suffers
  from mild dyslexia and can't remember if the command is IfEnd or
  EndIf, so both are permitted. Use whichever is more comfortable for
  you.

</DD>
<DT><A NAME="foot11641">... strings.</A><A
 HREF="node21.html#tex2html85"><SUP><SPAN CLASS="arabic">21</SPAN>.<SPAN CLASS="arabic">5</SPAN></SUP></A></DT>
<DD>For this comparison
  float values are used. Rounding errors can cause equality
  comparisons to fail.

</DD>
</DL>
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<ADDRESS>
Bob van der Poel
2016-06-11
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