diff options
Diffstat (limited to 'txr.1')
| -rw-r--r-- | txr.1 | 30 |
1 files changed, 12 insertions, 18 deletions
@@ -10599,11 +10599,9 @@ dohash early using (return) or (return <value>). .TP Syntax: - (hash-uni <hash1> <hash2>) - (hash-guni <hash1> <hash2>) + (hash-uni <hash1> <hash2> [<join-func>]) (hash-diff <hash1> <hash2>) - (hash-isec <hash1> <hash2>) - (hash-gisec <hash1> <hash2>) + (hash-isec <hash1> <hash2> [<join-func>]) .TP Description: @@ -10621,26 +10619,22 @@ keys, and so forth. The hash-uni function performs a set union. The resulting hash contains all of the keys from <hash1> and all of the keys from <hash2>, and their corresponding values. If a key occurs both in <hash1> and <hash2>, then it occurs only once -in the resulting hash. The value for this common key is the one from <hash2>. -The hash-guni function is similar, except that if a key occurs in both <hash1> -and <hash2>, then the respective data items from <hash1> and <hash2> for that -key appear appended together in the resulting hash as if by the append -function, in that order. (The hash-guni name is a reference to the group-by -function. A sequence of data items can be grouped in multiple ways, and then -the hashes combined with hash-guni.) +in the resulting hash. In this case, if the <join-func> argument is not given +specified, value associated with this key is the one from <hash1>. If +<join-func> is specified then it is called with two arguments: the respective +data items from <hash1> and <hash2>. The return value of this function is used +as the value in the union hash. The hash-diff function performs a set difference. First, a copy of <hash1> is made as if by the copy-has function. Then from this copy, all keys which occur in <hash2> are deleted. The hash-isec function performs a set intersection. The resulting hash contains -only those keys which occur both in <hash1> and <hash2>. The values selected -for these common keys are those from <hash1>. - -The hash-gisec function performs a set intersection similarly to hash-isec. -However, for each key placed in the resulting hash, the associated data is -formed by appending together the data item from <hash1> and from <hash2>, in -that order. +only those keys which occur both in <hash1> and <hash2>. If <join-func> is not +specified, the values selected for these common keys are those from <hash1>. +If <join-func> is specified, then for each key which occurs in both <hash1> and +<hash2>, it is called with two arguments: the respective data items. The return +value is then used as the data item in the intersection hash. .SH PARTIAL EVALUATION AND COMBINATORS |