00c881d0da
The data type system is very hard to understand. Many people don't
understand why
type_of([1,2,3]) == Array
will fail, but
type_of([1,2,3]) <= Array
passes. This does a simpler validation that doesn't rely on explicit
data types. Instead, use
$foo = [1,2,3]
if $foo.is_a(Array) {
notify { 'This is an array': }
}
This is based on code by Ben Ford <ben.ford@puppetlabs.com>.
* Added acceptance tests
* Added dispatch
* Improved unit tests
* Added docs to README
32 lines
933 B
Ruby
32 lines
933 B
Ruby
# Boolean check to determine whether a variable is of a given data type. This is equivalent to the `=~` type checks.
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#
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# @example how to check a data type
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# # check a data type
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# foo = 3
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# $bar = [1,2,3]
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# $baz = 'A string!'
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#
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# if $foo.is_a(Integer) {
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# notify { 'foo!': }
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# }
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# if $bar.is_a(Array) {
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# notify { 'bar!': }
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# }
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# if $baz.is_a(String) {
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# notify { 'baz!': }
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# }
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#
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# See the documentation for "The Puppet Type System" for more information about types.
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# See the `assert_type()` function for flexible ways to assert the type of a value.
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#
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Puppet::Functions.create_function(:is_a) do
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dispatch :is_a do
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param 'Any', :value
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param 'Type', :type
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end
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def is_a(value, type)
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# See puppet's lib/puppet/pops/evaluator/evaluator_impl.rb eval_MatchExpression
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Puppet::Pops::Types::TypeCalculator.instance?(type, value)
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end
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end
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