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[MAINT] Improve 'try_get_value' readme

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Dmitry Ilyin 2015-09-04 19:12:21 +03:00
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@ -706,12 +706,18 @@ Converts the argument into bytes, for example "4 kB" becomes "4096". Takes a sin
*Type*: rvalue.
Looks up into a complex structure of arrays and hashes and returns a value
or the default value if nothing was found.
Looks up into a complex structure of arrays and hashes to extract a value by
its path in the structure. The path is a string of hash keys or array indexes
starting with zero, separated by the path separator character (default "/").
The function will go down the structure by each path component and will try to
return the value at the end of the path.
Key can contain slashes to describe path components. The function will go down
the structure and try to extract the required value.
In addition to the required "path" argument the function accepts the default
argument. It will be returned if the path is not correct, no value was found or
a any other error have occurred. And the last argument can set the path
separator character.
```ruby
$data = {
'a' => {
'b' => [
@ -722,19 +728,28 @@ $data = {
}
}
$value = try_get_value($data, 'a/b/2')
# $value = 'b3'
# with all possible options
$value = try_get_value($data, 'a/b/2', 'not_found', '/')
=> $value = 'b3'
# $value = 'b3'
a -> first hash key
b -> second hash key
2 -> array index starting with 0
# using the default value
$value = try_get_value($data, 'a/b/c/d', 'not_found')
# $value = 'not_found'
not_found -> (optional) will be returned if there is no value or the path did not match. Defaults to nil.
/ -> (optional) path delimiter. Defaults to '/'.
# using custom separator
$value = try_get_value($data, 'a|b', [], '|')
# $value = ['b1','b2','b3']
```
In addition to the required "key" argument, "try_get_value" accepts default
argument. It will be returned if no value was found or a path component is
missing. And the fourth argument can set a variable path separator.
1. **$data** The data structure we are working with.
2. **'a/b/2'** The path string.
3. **'not_found'** The default value. It will be returned if nothing is found.
(optional, defaults to *undef*)
4. **'/'** The path separator character.
(optional, defaults to *'/'*)
#### `type3x`