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| Previous: <a rel="previous" accesskey="p" href="Prefix-Ops.html#Prefix-Ops">Prefix Ops</a>, |
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| |
| <h4 class="subsection">6.2.4 Infix Operators</h4> |
| |
| <p><a name="index-infix-operators-259"></a><a name="index-operators_002c-permitted-arguments-260"></a><dfn>Infix operators</dfn> take two arguments, one on either side. Operators |
| have precedence, but operations with equal precedence are performed left |
| to right. Apart from <code>+</code> or <samp><span class="option">-</span></samp>, both arguments must be |
| absolute, and the result is absolute. |
| |
| <ol type=1 start=1> |
| <a name="index-operator-precedence-261"></a><a name="index-precedence-of-operators-262"></a> |
| <li>Highest Precedence |
| |
| <dl> |
| <dt><code>*</code><dd><dfn>Multiplication</dfn>. |
| |
| <br><dt><code>/</code><dd><dfn>Division</dfn>. Truncation is the same as the C operator ‘<samp><span class="samp">/</span></samp>’ |
| |
| <br><dt><code>%</code><dd><dfn>Remainder</dfn>. |
| |
| <br><dt><code><<</code><dd><dfn>Shift Left</dfn>. Same as the C operator ‘<samp><span class="samp"><<</span></samp>’. |
| |
| <br><dt><code>>></code><dd><dfn>Shift Right</dfn>. Same as the C operator ‘<samp><span class="samp">>></span></samp>’. |
| </dl> |
| |
| <li>Intermediate precedence |
| |
| <dl> |
| <dt><code>|</code><dd> |
| <dfn>Bitwise Inclusive Or</dfn>. |
| |
| <br><dt><code>&</code><dd><dfn>Bitwise And</dfn>. |
| |
| <br><dt><code>^</code><dd><dfn>Bitwise Exclusive Or</dfn>. |
| |
| <br><dt><code>!</code><dd><dfn>Bitwise Or Not</dfn>. |
| </dl> |
| |
| <li>Low Precedence |
| |
| |
| <a name="index-addition_002c-permitted-arguments-263"></a> |
| <a name="index-plus_002c-permitted-arguments-264"></a> |
| <a name="index-arguments-for-addition-265"></a> |
| <dl><dt><code>+</code><dd><dfn>Addition</dfn>. If either argument is absolute, the result has the section of |
| the other argument. You may not add together arguments from different |
| sections. |
| |
| <p><a name="index-subtraction_002c-permitted-arguments-266"></a><a name="index-minus_002c-permitted-arguments-267"></a><a name="index-arguments-for-subtraction-268"></a><br><dt><code>-</code><dd><dfn>Subtraction</dfn>. If the right argument is absolute, the |
| result has the section of the left argument. |
| If both arguments are in the same section, the result is absolute. |
| You may not subtract arguments from different sections. |
| <!-- FIXME is there still something useful to say about undefined - undefined ? --> |
| |
| <p><a name="index-comparison-expressions-269"></a><a name="index-expressions_002c-comparison-270"></a><br><dt><code>==</code><dd><dfn>Is Equal To</dfn> |
| <br><dt><code><></code><dt><code>!=</code><dd><dfn>Is Not Equal To</dfn> |
| <br><dt><code><</code><dd><dfn>Is Less Than</dfn> |
| <br><dt><code>></code><dd><dfn>Is Greater Than</dfn> |
| <br><dt><code>>=</code><dd><dfn>Is Greater Than Or Equal To</dfn> |
| <br><dt><code><=</code><dd><dfn>Is Less Than Or Equal To</dfn> |
| |
| <p>The comparison operators can be used as infix operators. A true results has a |
| value of -1 whereas a false result has a value of 0. Note, these operators |
| perform signed comparisons. |
| </dl> |
| |
| <li>Lowest Precedence |
| |
| <dl> |
| <dt><code>&&</code><dd><dfn>Logical And</dfn>. |
| |
| <br><dt><code>||</code><dd><dfn>Logical Or</dfn>. |
| |
| <p>These two logical operations can be used to combine the results of sub |
| expressions. Note, unlike the comparison operators a true result returns a |
| value of 1 but a false results does still return 0. Also note that the logical |
| or operator has a slightly lower precedence than logical and. |
| |
| </dl> |
| </ol> |
| |
| <p>In short, it's only meaningful to add or subtract the <em>offsets</em> in an |
| address; you can only have a defined section in one of the two arguments. |
| |
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