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69 lines
2.0 KiB
Plaintext
69 lines
2.0 KiB
Plaintext
=== Module Definitions
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A *module definition* provides a named scope that encloses other
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definitions, including other module definitions.
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==== Syntax
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`module`
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<<Lexical-Elements_Identifiers,_identifier_>>
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`{` _module-member-sequence_ `}`
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_module-member-sequence_ is an
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<<Element-Sequences,element sequence>> in
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which each element is a *module member*,
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and the terminating punctuation is a semicolon.
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A module member is one of the following:
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* A <<Definitions_Component-Definitions,component definition>>
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* A <<Definitions_Component-Instance-Definitions,component instance definition>>
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* A <<Definitions_Constant-Definitions,constant definition>>
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* A <<Definitions_Module-Definitions,module definition>>
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* A <<Definitions_Port-Definitions,port definition>>
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* A <<Definitions_Struct-Definitions,struct definition>>
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* A <<Definitions_Topology-Definitions,topology definition>>
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* A <<Specifiers_Location-Specifiers,location specifier>>
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* An <<Definitions_Abstract-Type-Definitions,abstract type definition>>
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* An <<Definitions_Array-Definitions,array definition>>
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* An <<Definitions_Enum-Definitions,enum definition>>
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* An <<Specifiers_Include-Specifiers,include specifier>>
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* An <<Specifiers_Init-Specifiers,init specifier>>
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==== Semantics
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A module definition _D_ qualifies the names of all the definitions
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inside it with its own name. Inside _D_, you can refer to definitions in
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_D_ by their unqualified name (the identifier appearing in the
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definition) or by their qualified name. Outside _D_, you have to use the
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qualified name. We say that the *scope* of the identifiers in the
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definitions in _D_ is limited to the inside of _D_.
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For further information about name scoping and qualification, see the
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section on
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<<Scoping-of-Names,Scoping of Names>>.
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==== Example
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[source,fpp]
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----
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module M {
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constant a = 0
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constant b = a # Inside M, we can refer to M.a as a
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constant c = M.a # We can also say M.a here
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}
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constant d = M.a # Outside M, we have to say M.a
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constant e = a # Error: a is not in scope here
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----
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