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− | {{ | + | {{mIRC Guide}} |
− | + | Normal code is executed, as you are probably aware, top down and left right. '''Evaluation brackets''' are a mechanism by which a program can alter the natural behavior of the [[mIRC]] [[interpreter]]. | |
Evaluation brackets allows us to: | Evaluation brackets allows us to: | ||
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[[File:Eval1.png]] | [[File:Eval1.png]] | ||
− | + | A typical code is evaluated from left to right, one word at a time. | |
<source lang="mIRC">alias x echo -a $1 | return $1 | <source lang="mIRC">alias x echo -a $1 | return $1 | ||
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=== Multiple evaluations === | === Multiple evaluations === | ||
− | If we follow the simple rule above, we can easily evaluate a specific code segment multiple | + | If we follow the simple rule above, we can easily evaluate a specific code segment multiple files. Consider the following example: |
<source lang="mIRC">alias exe echo -a I was called! | return Hi! | <source lang="mIRC">alias exe echo -a I was called! | return Hi! | ||
; example: | ; example: | ||
− | alias example echo -a [ [ [ $!!exe ] ] ]</source> | + | alias example echo -a [ [ [ [ [ $!!!!exe ] ] ] ] ]</source> |
The above code prints: | The above code prints: | ||
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I was called! | I was called! | ||
Hi! | Hi! | ||
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[[File:Eval6.png]] | [[File:Eval6.png]] | ||
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Here is a more interesting example of multiple evaluations: | Here is a more interesting example of multiple evaluations: | ||
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== Solving the space issue using $+() == | == Solving the space issue using $+() == | ||
− | By | + | By know we already know that the following code will only evaluated once since it violates the first rule: spaces in the code segment. |
<source lang="mIRC">//echo -a [ [ a $!me ] ]</source> | <source lang="mIRC">//echo -a [ [ a $!me ] ]</source> | ||
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== $+ Special behaviors == | == $+ Special behaviors == | ||
− | Inside evaluation brackets, the $+ concatenation | + | Inside evaluation brackets, the $+ concatenation bracket exhibit some special behavior. |
=== [ A $+ B ] Format === | === [ A $+ B ] Format === | ||
The rule about [ A $+ B ] is: | The rule about [ A $+ B ] is: | ||
− | The '''[ token_A $+ token_B ]''' arrangement will cause token_A to evaluate once and then be concatenated to token_B (evaluated zero times) | + | The '''[ token_A $+ token_B ]''' arrangement will cause token_A to evaluate once and then be concatenated to token_B (evaluated zero times). I.e.: |
[ A $+ B ] <=> $($(A, 1) $+ $(B, 0), 2) | [ A $+ B ] <=> $($(A, 1) $+ $(B, 0), 2) | ||
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The most common form is %var. [ $+ [ $nick ] ] which allow you to retrieve a value from a variable specifically created for $nick. | The most common form is %var. [ $+ [ $nick ] ] which allow you to retrieve a value from a variable specifically created for $nick. | ||
+ | == Escaping Evaluation Brackets == | ||
+ | Evaluation brackets can be escaped by using double brackets ([[) without spaces. For example: | ||
− | = | + | <source lang="mIRC">//echo -a [[ [[ example! ]] ]] </source> |
− | |||
− | + | The code above prints: | |
+ | [ [ example! ] ] | ||
− | + | Note that without a complete pair, a single bracket is not treated as anything special. The following example is also acceptable: | |
− | + | <source lang="mIRC">//echo -a [[ [[ example! ] ]</source> | |
− | + | It's a good time to also note that escaped evaluation brackets are not exactly the same as using $chr(91) and $chr(93). The escaped evaluation brackets happen at the same phase of evaluation as the actual evaluation bracket processing. Consider the following example: | |
− | //echo -a | + | <source lang="mIRC">//echo -a $mid( [[ [[ example! ]] ]] , 1) => $mid( $chr(91) example! $chr(93) , 1)</source> |
− | + | The code above prints: | |
+ | example! => [ example! ] | ||
− | + | == Special behavior inside identifiers == | |
+ | By now you know evaluation brackets happen before the code itself evaluates. It turns out that when an identifier evaluates, it will correctly parse code that is a direct result of the evaluation brackets. Here is some code to demonstrate this behavior: | ||
<source lang="mIRC">//var -s %x = mid(@Example!,2,8, %y = ) | echo -a $ [ $+ [ %x $+ [ %y ] ] ]</source> | <source lang="mIRC">//var -s %x = mid(@Example!,2,8, %y = ) | echo -a $ [ $+ [ %x $+ [ %y ] ] ]</source> | ||
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The interpreter is able to handle the commas and braces as part of the code. | The interpreter is able to handle the commas and braces as part of the code. | ||
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== Additional Odd Behaviors == | == Additional Odd Behaviors == | ||
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The above code prints: | The above code prints: | ||
$!me$me vs. $me$!me | $!me$me vs. $me$!me | ||
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== Commands with Special Behavior == | == Commands with Special Behavior == | ||
Not all commands are equal. Below is a list of some regular commands that have special evaluation routines that allow us to get the job that would otherwise require evaluation brackets: | Not all commands are equal. Below is a list of some regular commands that have special evaluation routines that allow us to get the job that would otherwise require evaluation brackets: | ||
− | # | + | #[[/var command - mIRC|/var]] |
− | # | + | #[[/set command - mIRC|/set]] |
− | # | + | #[[/inc command - mIRC|/inc]] |
− | # | + | #[[/dec command - mIRC|/dec]] |
− | # | + | #[[/unset command - mIRC|/unset]] |
− | # | + | #[[/sockwrite command - mIRC|/sockwrite]] |
<source lang="mIRC">alias example { | <source lang="mIRC">alias example { | ||
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: | : | ||
− | Note that unlike the reset of the commands, ''' | + | Note that unlike the reset of the commands, '''[[/unset command - mIRC|/unset]]''' cannot set variables in the format of %var [[$+ - mIRC|$+]] %var. Evaluation brackets are needed to fix this. This is most likely a bug. |
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− | [[Category:mIRC | + | [[Category:mIRC]] |