fix descripting of struct-field-index (PR 9685)
svn: r11223
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@ -106,8 +106,7 @@ multiple times, attaches a property value to the structure type; see
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@margin-note{Use the @scheme[prop:procedure] to property implement an
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@as-index{applicable structure}, use @scheme[prop:evt] to create a
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structure type whose instances are @tech{synchronizable events}, and
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so on. By convention, property names usually start with
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@schemeidfont{prop:}.}
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so on. By convention, property names start with @schemeidfont{prop:}.}
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The @scheme[#:prefab] option obtains a @techlink{prefab} (pre-defined,
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globally shared) structure type, as opposed to creating a new
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@ -162,11 +161,14 @@ cp
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This form can only appear as an expression within a
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@scheme[define-struct] form; normally, it is used with
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@scheme[#:property], especially for a property like
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@scheme[prop:procedure]. The result of
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@scheme[prop:procedure]. The result of a @scheme[struct-field-index]
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expression is an exact, non-negative integer that corresponds to the
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position within the structure declaration of the field named by
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@scheme[field-id].
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@defexamples[
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#:eval posn-eval
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(define-struct mood-procedure ([base] rating)
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(define-struct mood-procedure (base rating)
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#:property prop:procedure (struct-field-index base))
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(define happy+ (make-mood-procedure add1 10))
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(happy+ 2)
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