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<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Toplevel Syntax</title><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot"><link rel="home" href="index.html" title="Genius Manual"><link rel="up" href="ch07.html" title="Chapter 7. Advanced Programming with GEL"><link rel="prev" href="ch07.html" title="Chapter 7. Advanced Programming with GEL"><link rel="next" href="ch07s03.html" title="Returning Functions"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Toplevel Syntax</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch07.html">Prev</a> </td><th width="60%" align="center">Chapter 7. Advanced Programming with GEL</th><td width="20%" align="right"> <a accesskey="n" href="ch07s03.html">Next</a></td></tr></table><hr></div><div class="sect1"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="genius-gel-toplevel-syntax"></a>Toplevel Syntax</h2></div></div></div><p>
The syntax is slightly different if you enter statements on
the top level versus when they are inside parentheses or
inside functions. On the top level, enter acts the same as if
you press return on the command line. Therefore think of programs
as just a sequence of lines as if they were entered on the command line.
In particular, you do not need to enter the separator at the end of the
line (unless it is part of several statements inside
parentheses). When a statement does not end with a separator on the
top level, the result is printed after being executed.
</p><p>
For example,
</p><pre class="programlisting">function f(x)=x^2
f(3)
</pre><p>
will print first the result of setting a function (a representation of
the function, in this case <code class="computeroutput">(`(x)=(x^2))</code>)
and then the expected 9. To avoid this, enter a separator
after the function definition.
</p><pre class="programlisting">function f(x)=x^2;
f(3)
</pre><p>
If you need to put a separator into your function then you have to surround with
parenthesis. For example:
</p><pre class="programlisting">function f(x)=(
y=1;
for j=1 to x do
y = y+j;
y^2
);
</pre><p>
</p><p>
The following code will produce an error when entered on the top
level of a program, while it will work just fine in a function.
</p><pre class="programlisting">if Something() then
DoSomething()
else
DoSomethingElse()
</pre><p>
</p><p>
The problem is that after <span class="application">Genius Mathematics Tool</span> sees the end of line after the
second line, it will decide that we have whole statement and
it will execute it. After the execution is done, <span class="application">Genius Mathematics Tool</span> will
go on to the next
line, it will see <code class="literal">else</code>, and it will produce
a parsing error. To fix this, use parentheses. <span class="application">Genius Mathematics Tool</span> will not
be satisfied until it has found that all parentheses are closed.
</p><pre class="programlisting">if Something() then (
DoSomething()
) else (
DoSomethingElse()
)
</pre><p>
</p></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ch07.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch07.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="ch07s03.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Chapter 7. Advanced Programming with GEL </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> Returning Functions</td></tr></table></div></body></html>
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