Changeset 39530 in project

Timestamp:

01/26/21 14:18:07 (3 months ago)

Author:

sjamaan

Message:

defstruct: Clarify that the default value for slots without initializers is #f

File:

• wiki/eggref/5/defstruct (modified) (2 diffs)

wiki/eggref/5/defstruct

@@ -24 +24 @@
 or a list of the form {{(NAME INIT)}} where {{INIT}} is the default
 value of the slot (the {{INIT}} expression will only be evaluated when
-no value is given in the constructor procedure).  The {{defstruct}}
-macro expands into predicate and accessor functions (just like the
-native {{define-record}}):
+no value is given in the constructor procedure. It defaults to {{#f}}
+when none is provided).
+
+The {{defstruct}} macro expands into predicate and accessor functions
+(just like the native {{define-record}}):
 
 <enscript highlight="scheme">
@@ -49 +51 @@
  => ; a point with x = 99 and y = 42
 </enscript>
+
+If keywords for some slots are missing, their initialization values
+default to those supplied in the {{defstruct}} call, or else {{#f}}.
 
 There are also two procedures {{update-STRUCTNAME}} and