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Normal arguments vs. keyword arguments
How are "keyword arguments" different from regular arguments? Can't all arguments be passed as name=value instead of using positional syntax?
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MySQL error 2006: mysql server has gone away
...termittent then its better to release your connection so you don't used up all the connections. Rebuilding the connection is generally cheap. +1
– Yzmir Ramirez
Nov 3 '11 at 0:48
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How to delete a row by reference in data.table?
.... 'keep.idxs'
keep.idxs <- setdiff(DT[, .I], del.idxs); # select row indexes to keep
cols = names(DT);
DT.subset <- data.table(DT[[1]][keep.idxs]); # this is the subsetted table
setnames(DT.subset, cols[1]);
for (col in cols[2:length(cols)]) {
DT.subset[, (col) := DT[[col]][keep...
List submodules in a Git repository
...ently checked out submodule commit does not match the SHA-1
found in the index of the containing repository and U if the submodule
has merge conflicts.
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Using .gitignore to ignore everything but specific directories
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Here's how I did it - you essentially have to walk up the paths, you can't wildcard more than one level in any direction:
# Ignore everything:
*
# Except for the themes directories:
!wordpress/
!wordpress/*/
!wordpress/*/wp-content/
!wordpress/*/wp-conten...
How to clone a case class instance and change just one field in Scala?
...ind a reference to copy in the "obvious" spots, scala-lang.org/api/current/index.html for instance.
– François Beausoleil
Aug 30 '11 at 20:38
6
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Haskell: Lists, Arrays, Vectors, Sequences
...widely used.
On the other hand
The first problem with lists is that to index into them (!!) takes ϴ(k) time, which is annoying. Also, appends can be slow ++, but Haskell's lazy evaluation model means that these can be treated as fully amortized, if they happen at all.
The second problem with l...
INSERT INTO vs SELECT INTO
...erformance implications? If the table is a permanent table, you can create indexes at the time of table creation which has implications for performance both negatively and positiviely. Select into does not recreate indexes that exist on current tables and thus subsequent use of the table may be slow...
mysql check collation of a table
...ion | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |
+------+--------+---------+------------+------+----------------+---------...
form_for with nested resources
...date]
resources :articles do
resources :comments, :only => [:create, :index, :new]
end
I guess it's ok to have duplicate routes, and to miss a few unit-tests. (Why test? Because even if the user never sees the duplicates, your forms may refer to them, either implicitly or via named routes.) S...