diff options
| -rw-r--r-- | txr.1 | 30 |
1 files changed, 27 insertions, 3 deletions
@@ -24162,7 +24162,8 @@ Note: if an method is defined or redefined with different semantics for a struct type whose instances have already been inserted as keys in an .code :equal-based -hash table, searches for those keys will not work reliably. +hash table, the behavior of subsequent insertion and lookup operations +on that hash table become unspecified. .coNP Method @ print .synb @@ -37090,6 +37091,24 @@ is fully instantiated. In the meanwhile, the \*(TX program can mutate the hash table from which the lazy list is being generated. +Certain hash operations expose access to the internal key-value association +entries of a hash table, which are represented as ordinary +.code cons +cells. Modifying the +.code car +field of such a cell potentially violates the integrity of the hash table; +the behavior of subsequent lookup and insertion operations becomes unspecified. + +Similarly, if an object is used as a key in an +.codn equal -based +hash table, and that object is mutated in such a way that its equality to +other objects under the +.code equal +function is affected or its hash value under +.code hash-equal +is altered, the behavior of subsequent lookup and insertion operations on the +becomes unspecified. + .coNP Functions @ hash-construct and @ hash-from-pairs .synb .mets (hash-construct < hash-args << key-val-pairs ) @@ -37404,7 +37423,10 @@ continues to exist inside modifying the .code car field of the returned cons has ramifications for the logical integrity of -the hash. Modifying the +the hash; doing so results in unspecified behavior for subsequent +insertion and lookup operations. + +Modifying the .code cdr field has the effect of updating the association with a new value. @@ -37779,7 +37801,9 @@ conses. Modifying the fields of these conses constitutes modifying the hash values in the original hash table. Modifying the .code car -fields interferes with the integrity of the hash table. +fields interferes with the integrity of the hash table, +resulting in unspecified behavior for subsequent hash insertion +and lookup operations. These functions all retrieve the keys and values in the same order. For example, if the keys are retrieved with |