|From:||Mr. Brian B. McGuinness|
|Subject:||Comments on GNU APL|
|Date:||Thu, 9 Jan 2020 19:53:17 +0000|
1. On startup of GNU APL 1.8 I get the error message:
The following directories and file names were tried:
file ./libemacs.so (No such file or directory)
file ./libemacs.dylib (No such file or directory)
file ./libemacs (No such file or directory)
The file is /usr/lib64/apl/libemacs.so (the installer apparently placed it there).
2. )DUMP should always store floating point values whose magnitudes are less
than 1 in scientific notation to preserve precision.
For example, if I do
WAS CLEAR WS
sec2rad ← 4.8481368110953599359e¯6
and then I look at the test.apl file, I see
so I have lost five digits.
I am tempted to use )DUMP instead of )SAVE as it stores workspaces in a more
compact and easily readable form that does not become obsolete as new
versions of GNU APL are released.
3. I am strongly opposed to the use of the axis parameter for passing arbitrary
data to a function as a third argument. This is very confusing to people
trying to read the code. When I see brackets, I expect the contents to be
either a genuine axis specification or an index into an array. A better
approach would be to pass arguments in a nested array and then unpack them
with a statement such as (A B C) ← ARGUMENTS.
Alternatively, APL2 could be extended to allow the use of data as
operands for operators, as in J. Then the operator operands could be used
as third and fourth arguments. That would allow #FIO and other such
functions to be implemented in much the same way as the foreign conjunction
4. ]boxing is very helpful.
5. I would like to see #RE extended to support replacement operations with
back-substitution as well as searches. For example, one might enter
TEXT ← ('"(\w)' '“$1') #RE['g'] TEXT
to replace double quotes preceding words with "“".
But I would prefer a syntax like
TEXT ← '/"(\w)/“$1/g' #RE TEXT
to avoid abusing the axis selector.
|[Prev in Thread]||Current Thread||[Next in Thread]|