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<head><title>value(String) -- evaluate a string</title>
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<div><h1>value(String) -- evaluate a string</h1>
<div class="single"><h2>Synopsis</h2>
<ul><li><div class="list"><dl class="element"><dt class="heading">Usage: </dt><dd class="value"><div><tt>value s</tt></div>
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<li><span>Function: <a href="_value.html" title="evaluate">value</a></span></li>
<li><div class="single">Inputs:<ul><li><span><tt>s</tt>, <span>a <a href="___String.html">string</a></span></span></li>
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<li><div class="single">Outputs:<ul><li><span>the value obtained by evaluating the code in <tt>s</tt></span></li>
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<div class="single"><h2>Description</h2>
<div>The contents of <tt>s</tt> are treated as code in the Macaulay2 language, parsed it in its own scope (the same way a file is) and evaluated. The string may contain multiple lines.<table class="examples"><tr><td><pre>i1 : value "2 + 2"
o1 = 4</pre>
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<tr><td><pre>i2 : value "a := 33
a+a"
o2 = 66</pre>
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<tr><td><pre>i3 : a
o3 = a
o3 : Symbol</pre>
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Since the local assignment to <tt>a</tt> above occurred in a new scope, the value of the global variable <tt>a</tt> is unaffected.<p>During evaluation of the string, error messages will refer to the location of the error as <tt>currentString</tt> with a line number and a column number, and the value of the variable <a href="_value_lp__String_rp.html" title="evaluate a string">currentString</a> is set to the string, to aid in debugging.</p>
<table class="examples"><tr><td><pre>i4 : debuggingMode = stopIfError = false;</pre>
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<tr><td><pre>i5 : value "1/0"
currentString:1:2:(3):[1]: error: division by zero</pre>
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<tr><td><pre>i6 : debuggingMode = true;</pre>
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<tr><td><pre>i7 : value "1/0"
currentString:1:2:(3):[1]: error: division by zero
currentString:1:2:(3):[1]: --entering debugger (type help to see debugger commands)
currentString:1:1-1:3: --source code:
1/0</pre>
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<tr><td><pre>ii8 : break</pre>
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<div class="single"><h2>See also</h2>
<ul><li><span><a href="_debugging.html" title="">debugging</a></span></li>
<li><span><a href="_stop__If__Error.html" title="whether to stop the program when an error occurs">stopIfError</a> -- whether to stop the program when an error occurs</span></li>
<li><span><a href="_debugging__Mode.html" title="whether to enter the debugger when an error occurs">debuggingMode</a> -- whether to enter the debugger when an error occurs</span></li>
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