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Does anyone out there know about examples and the theory behind parsers that will take (maybe) an abstract syntax tree and produce code, instead of vice-versa. Mathematically, at least intuitively, I believe the function of code->AST is reversible,...
Started by Dervin Thunk on
, 8 posts
by 8 people.
Answer Snippets (Read the full thread at stackoverflow):
I rather like lewap's response:
find a mathematical way to express a visitor and you have a dual to the parser
But you asked... .
Is traverses the tree and does whatever has to be done, for example optimize or generate code .
Such thing is called a Visitor.
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I want to setup a mechanism for tracking DB schema changes, such the one described in this answer :
For every change you make to the database, you write a new migration. Migrations typically have two methods: an "up" method in which the changes are applied...
Started by Panos on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
That said, Rails offers a way to mark a migration .
Migration I've ever done is reversible.
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EDIT: Can anybody actually answer the question? Thanks, I don't need no audit trail, I WILL know all the passwords and users can't change them and I will continue to do so.
This is not for hacking!
We recently migrated away from a old and rusty Linux/...
Answer Snippets (Read the full thread at serverfault):
With all that said, you should not use reversible encryption and you.
Don't enable "reversible to work against those OSes.
With a moderately complex password would be nearly impossible to discover .
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I seem to have faced this problem many times and I wanted to ask the community whether I am just barking up the wrong tree. Basically my question can be distilled down to this: if I have an enum (in Java) for which the values are important, should I be...
Started by Kidburla on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
There's no need for a "reversible map" - the version which takes the month number.
More simply.
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Hey everyone,
One concept I've always wondered about is the use of cryptographic hash functions and values. I understand that these functions can generate a hash value that is unique and virtually impossible to reverse, but here's what I've always wondered...
Started by barfoon on
, 12 posts
by 12 people.
Answer Snippets (Read the full thread at stackoverflow):
Though in theory MD5 is not reversible....
If hash functions such as MD5 were reversible then it would have been a watershed event in the history of data compression algorithms! Its easy to see that if MD5 were reversible.
Freebl library).
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I'd like to store some data in Python in a similar form to a dictionary: {1:'a', 2:'b'} . Every value will be unique, not just among other values, but among keys too.
Is there a simple data structure that I can use to get the corresponding object no matter...
Started by Alex Jurkiewicz on
, 7 posts
by 7 people.
Answer Snippets (Read the full thread at stackoverflow):
Related posts:
Python mapping inverse
Python 1:1 mappings
Of course, if all values and keys are unique, couldn't you just use a single dictionary, and insert both key:value and value:key initially?
Insert reversed pair of (key, value) into same....
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I'm trying to make a function in Python that does the equivalent of compile(), but also lets me get the original string back. Let's call those two functions comp() and decomp(), for disambiguation purposes. That is,
a = comp("2 * (3 + x)", "", "eval")...
Started by Joe on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Something like this:
class CodeObjectEnhanced(object): def __init__(self, *args): self.compiled = compile(*args) self.original = args[0] def comp(*args): return CodeObjectEnhanced(*args)
... .
My approach would be to wrap the code object in another object .
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Super Hot, Happy Nappers Children Reversible Pillow on sale for $2.99 + Free in store pickup @bestbuy Go to Bestbuy.com for Super Hot, Happy Nappers Children Reversible Pillow on sale for $2.99 + Free in store pickup .
, 1 posts
Answer Snippets (Read the full thread at dealswell):
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Male Birth Control: New Procedure Is 100 Percent Effective, Reversible
A new birth control procedure shows promising signs of becoming another viable option for people who don't want children now, but may want them some day.
Techcitement points out that...
Started by CepheiA on
, 30 posts
by 21 people.
Answer Snippets (Read the full thread at 600rr):
Surgery ends up being the....
It can take years to get an infection know as epididymitis which can cause major swelling and inflammation for the rest of your life .
Better hope 0% of outside bacteria is introduced to the epididymis through the vas deferens .
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Little Pet Shop..Reversible Pillowcase.. On Ebay: Little Pet Shop..Reversible Pillowcase..
US $6.99 (0 Bid)
43:47
Started by Ebay RSS on
, 1 posts
by 1 people.
Answer Snippets (Read the full thread at sociopets):
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