From 421706a042bb5668068e025b4b28de61694fbeae Mon Sep 17 00:00:00 2001 From: Matthew Flatt Date: Thu, 13 Mar 2008 21:04:07 +0000 Subject: [PATCH] fix sentence svn: r8968 --- collects/scribblings/guide/define-struct.scrbl | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/collects/scribblings/guide/define-struct.scrbl b/collects/scribblings/guide/define-struct.scrbl index ccfe77be46..89a3092ece 100644 --- a/collects/scribblings/guide/define-struct.scrbl +++ b/collects/scribblings/guide/define-struct.scrbl @@ -269,18 +269,19 @@ Every @tech{prefab} structure type is @tech{transparent}---but even less abstract than a @tech{transparent} type, because instances can be created without any access to a particular structure-type declaration or existing examples. Overall, the different options for structure -types cover a spectrum from more abstract to more convenient: +types offer a spectrum of possibilities from more abstract to more +convenient: @itemize{ - @item{@tech{Opaque} (the default) : instances cannot be inspected or + @item{@tech{Opaque} (the default) : Instances cannot be inspected or forged without access to the structure-type declaration. As discussed in the next section, @tech{constructor guards} and @tech{properties} can be attached to the structure type to further protect or to specialize the behavior of its instances.} - @item{@tech{Transparent} : anyone can inspect or create an instance + @item{@tech{Transparent} : Anyone can inspect or create an instance without access to the structure-type declaration, which means that the value printer can show the content of an instance. All instance creation passes through a @tech{constructor guard}, @@ -291,7 +292,7 @@ types cover a spectrum from more abstract to more convenient: name of the structure type, and therefore cannot be generated automatically by the expression reader. } - @item{@tech{Prefab} : anyone can inspect or create an instance at any + @item{@tech{Prefab} : Anyone can inspect or create an instance at any time, without prior access to a structure-type declaration or an example instance. Consequently, the expression reader can manufacture instances directly. The instance cannot have a @@ -300,9 +301,9 @@ types cover a spectrum from more abstract to more convenient: } Since the expression reader can generate @tech{prefab} instances, they -are useful when simple @tech{serialization} is needed and weak -abstraction is acceptable. @tech{Opaque} and @tech{transparent} -structures also can be serialized, however, if they are defined with +are useful when convenient @tech{serialization} is more important than +abstraction. @tech{Opaque} and @tech{transparent} structures also can +be serialized, however, if they are defined with @scheme[define-serializable-struct] as described in @secref["serialization"].