Changeset 826a67c


Ignore:
Timestamp:
Feb 9, 2018, 4:45:41 PM (4 years ago)
Author:
Aaron Moss <a3moss@…>
Branches:
aaron-thesis, arm-eh, cleanup-dtors, deferred_resn, demangler, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, resolv-new, with_gc
Children:
298ed08
Parents:
92f8e18
Message:

Clarify lvalue/rvalue nomenclature in paper

File:
1 edited

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  • doc/papers/general/Paper.tex

    r92f8e18 r826a67c  
    14001400a value that does not have a corresponding address is called a \newterm{rvalue} (for ``right-hand value''), while a value that does have an address is called a \newterm{lvalue} (for ``left-hand value'').
    14011401For example, in @int x; x = 42;@ the variable expression @x@ on the left-hand-side of the assignment is a lvalue, while the constant expression @42@ on the right-hand-side of the assignment is a rvalue.
    1402 In imperative programming, the address of a value is used for both reading and writing (mutating) a value.
     1402Despite the nomenclature of ``left-hand'' and ``right-hand'', an expression's classification as lvalue or rvalue is entirely dependent on whether it has an address or not; in imperative programming, the address of a value is used for both reading and writing (mutating) a value, and as such lvalues can be converted to rvalues and read from, but rvalues cannot be mutated because they lack a location to store the updated value.
    14031403
    14041404Within a lexical scope, lvalue expressions have an \newterm{address interpretation} for writing a value or a \newterm{value interpretation} to read a value.
     
    14601460Since pointers and references share the same internal representation, code using either is equally performant; in fact the \CFA compiler converts references to pointers internally, and the choice between them in user code can be made based solely on convenience.
    14611461
    1462 By analogy to pointers, \CFA references also allow cv-qualifiers:
     1462By analogy to pointers, \CFA references also allow cv-qualifiers such as @const@:
    14631463
    14641464\begin{cfa}
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