Difference between revisions of "Stateless and pure"
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[[Category:ECMA]] | [[Category:ECMA]] | ||
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| + | Stateless is first a semantic notion, meaning that a stateless feature does not refer to any state. To show that property to the clients, we add a syntactical notation based on the notion of constants in Eiffel, this looks like: | ||
<e>f (a: STRING): SOME_TYPE = | <e>f (a: STRING): SOME_TYPE = | ||
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... | ... | ||
end</e> | end</e> | ||
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| + | With some validity rules: | ||
| + | * only unqualified calls to stateless features are permitted. | ||
With some validity rules for redefinition: | With some validity rules for redefinition: | ||
| − | + | * once a routine is stateless its redefinitions have to be stateless. | |
| − | + | * a stateful routine can become stateless. | |
Latest revision as of 07:13, 29 June 2011
Stateless is first a semantic notion, meaning that a stateless feature does not refer to any state. To show that property to the clients, we add a syntactical notation based on the notion of constants in Eiffel, this looks like:
f (a: STRING): SOME_TYPE = do create Result.make (a) ... end
With some validity rules:
- only unqualified calls to stateless features are permitted.
With some validity rules for redefinition:
- once a routine is stateless its redefinitions have to be stateless.
- a stateful routine can become stateless.
