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I'm trying to create a logic expression parser for expressions like: ((VariableA -> VariableB) AND NOT VariableC) The parser should be able to return, wheather the result is true or false for given values of variables.
Basicly the expressions will ...
Started by Adam on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
If you use.
Sure there are already tools that do this (logic evaluation), but I couldn't find any.
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Can we put into a single regular expression , boolean logic : line starts with 'a' or 'b' . Question is triggered by using FileHelpers utility which does have a text box "Record Condition Selector" for "ExcludeIfMatchRegex" . Utility is written in C#....
Started by MicMit on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
How about this: ^[ab]
Having a hard time understanding you, but...if you're looking for a match if the string starts with "a" or "b", and a fail otherwise, you could do this:
^(a|b)(.+)$
Then, when you get the match's groups, the first group will be ... .
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So let's say I've got an expression like this:
((((e1) or (e2)) and (e3 or (e5 and e6)) and (e7)) or (e8))
I need to end up with a list of expressions (e1, e2, e3 etc) followed by and/or operators so that evaluating the list from left to right yields ...
Started by stu on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
You are on the right track with your thoughts about a parser, for indeed you need to parse (but not evaluate) the original expression, and then print it out in....
First off, what you are looking to do is convert infix notation to postfix notation .
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How can I store logical expressions using a RDBMS?
I tag objects and would like to be able to build truth statements based on those tags. (These might be considered as virtual tags.)
Tags
new
for_sale
used
offer
Rule
second_hand_goods = (!new or used)...
Started by chillitom on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
<logic type....
Your second hand goods logic could be stored as...
Using SQL Server 2005 or higher you can also store this nicely in a single table .
This in the past is to use XML to define the logic as it handles nesting very well.
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I am looking for an open source library in Java for parsing and building sql like expressions.
for example to evaluate validity of expressions like:
"(a = x or y ) and (b != z)"
in addition I want to have an API for building or extending expressions. ...
Started by LiorH on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Antlr is not pragmatic unless you have some basic parser knowledge. .
The grammatic looks very simple ( from here ) :P
Use script engine. .
I'm pretty sure you can have ANTLR do this for you .
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Regex expressions seems cocumbersome, they always drive me mad when trying to build it up. And i end up asking for help. But once i am given the result it looks really coool. Gurus, is there a way to go about it to break it up.
Started by zapping on
, 11 posts
by 11 people.
Answer Snippets (Read the full thread at stackoverflow):
Actually, the fundamentals aren't that hard to grasp....
The reference there is also invaluable as are the explanations how the regex engine works behind the scenes .
Yuo can start with tutorials at Regular-Expressions.info which provide a good starting point .
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In C#, given the two methods
bool Action1(object Data); bool Action2(object Data);
that are used in an if statement like this:
if ( Action1(Data) || (Action2(Data) ) { PerformOtherAction(); }
will Action2() still be called if Action1() returned true, ...
Started by Treb on
, 6 posts
by 6 people.
Answer Snippets (Read the full thread at stackoverflow):
Action2() will only be called if Action1() returns false
This is conceptually similar to
if (Action1(Data)) { PerformOtherAction(); } else if (Action2(Data)) { PerformOtherAction(); }
No, C# support logical short-circuiting so if Action1 returned....
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Apple Releases Logic Pro and Logic Express 9.1.7 Updates
Wednesday, March 28, the Logic Pro 9.1.7 and Logic Express 9.1.7 updates via their Software Update Utility and Mac App Store . According to the company, these updates provide compatibility with ...
Started by admin on
, 1 posts
by 1 people.
Answer Snippets (Read the full thread at 123macmini):
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Mac Users, After Logic Express Install, Can I Delete GarageBand Possibly idiotic question, but I have just installed Logic Express 9. I have checked the loops library, the instruments, and the plug-ins, and everything (except three incompatible plug-ins...
Started by Cobalt Blue on
, 20 posts
by 8 people.
Answer Snippets (Read the full thread at harmony-central):
I have checked deleted GarageBand until I found out that Logic Pro won't let me use the built in microphone in my -> Rest of the amp GarageBand....
By Cobalt Blue Possibly idiotic question, but I have just installed Logic Express 9.
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I am getting confused between domain/application logic and User Interface logic. To illustrate what I am trying to nail down, I will describe an imaginary program below for illustration purposes:
(1) Imagine a small application with a set of 3 cascading...
Started by Roberto Sebestyen on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
Personally, I would defineIn that situation where you have very specialized actions happening you need to put it in the logic putting logic relating....
express the desired UI logic in JavaScript or server-side is less important.
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