41 lines
1.6 KiB
Plaintext
41 lines
1.6 KiB
Plaintext
{ (define LIBNAME "Convert")
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(include "head.tinc") }
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<p>The teachpack <code>convert.ss</code> provides three functions:
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<menu>
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<li> <code>{(idx convert-gui)}</code>, which consumes a conversion function
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from Fahrenheit to Celsius and creates a graphical user interface
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with two rulers, which users can use to convert temperatures
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according to the given temperature conversion function
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<li> <code>{(idx convert-repl)}</code>, which consumes a conversion function
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from Fahrenheit to Celsius and then starts a read-evaluate-print
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loop. The loop prompts users to enter a number and then converts the
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number according to the given temperature conversion function.
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A user can exit the loop by entering <code>x</code>.
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<li> <code>{(idx convert-file)}</code>; it consumes a file name <code>in</code>, a
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conversion function from Fahrenheit to Celsius, and a string
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<code>out</code>. The program then reads a number from
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<code>in</code>, converts it according to the given temperature
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conversion function, and prints the result to the newly created file
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<code>out</code>. <br>
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<br><b>Warning:</b> If <code>out</code> already exists, it is
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deleted.
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</menu>
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<p>Example: Define a function <code>f2c</code> in the Definitons window.
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Set teachpack to <code>convert.ss</code> and execute. Then evaluate
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<pre>
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> (convert-gui f2c)
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>
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</pre>
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This will create a graphical user interface with two rulers. Slide the top
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one and click on convert to see the lower one move.</p>
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{(include "foot.tinc")}
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