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Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 30 |
1 files changed, 30 insertions, 0 deletions
@@ -31222,6 +31222,36 @@ or a subtype thereof. fa.(write 4) -> ;; error: fa has no such method .brev +.coNP Special variable @ *struct-clause-expander* +.desc +The +.code *struct-clause-expander* +special variable holds the hash table of associations between +keyword symbols and struct clause expander functions, defined by +.codn define-struct-clause . + +If the expression +.code "[*struct-clause-expander* :sym]" +yields a function, then symbol +.code :sym +has a binding as a struct clause macro. If that +expression yields +.codn nil , +then there is no such binding. + +The macro expanders in +.code *struct-clause-expander* +are two-parameter functions. The first parameter accepts the +clause to to be expanded. The second parameter accepts the +.code defstruct +form in which that clause is found; this is useful for error +reporting. + +An expander function returns a list of clauses, which may be any, possibly +empty mixture of primary clauses accepted by +.code defstruct +and clause macros. + .SS* Special Structure Functions Special structure functions are user-defined methods or structure functions |