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Clean up some argument profiles, enrich the docstring.

This commit is contained in:
Eric S. Raymond 2001-08-20 13:16:30 +00:00
parent d0688ebc10
commit 29bb115bae
2 changed files with 41 additions and 32 deletions
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28
Doc/lib/libcompilerlike.tex
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@ -31,7 +31,7 @@ simply passed as the first argument to the transformation function.
Typically it is a string that names the filter and is used in
generating error messages, but it could be arbitrary data.
The second argument, is interpreted as a list of filenames. The files
The second argument is interpreted as a list of filenames. The files
are transformed in left to right order in the list. A filename
consisting of a dash is interpreted as a directive to read from
standard input (this can be useful in pipelines).
@ -59,27 +59,27 @@ translation of that file has completed. Any tempfiles are removed
automatically on any exception thrown by the translation function,
and the exception is then passed upwards.
\begin{funcdesc}{filefilter}{name, arguments, trans_data\optional{,trans_file}}
Filter using a function taking the name and two file-object
\begin{funcdesc}{filefilter}{name, file, arguments, trans_data\optional{,trans_file}}
Filter using a function taking the name, filename, and two file-object
arguments. The function is expected to read data from the input file
object, transform it, and write the data to the output file object.
When the function terminates, the translation is done. The return
value of the transformation function is not used.
\end{funcdesc}
\begin{funcdesc}{linefilter}{name,arguments,trans_data\optional{,trans_file}}
Filter using a function taking the name and a string argument. The return
value of the function should be a string. This function is applied to
each line in the input file in turn; the return values become the
lines of the transformed file.
\begin{funcdesc}{linefilter}{name, file, arguments,trans_data\optional{,trans_file}}
Filter using a function taking the name, the filename, and a string
argument. The return value of the function should be a string. This
function is applied to each line in the input file in turn; the return
values become the lines of the transformed file.
\end{funcdesc}
\begin{funcdesc}{sponge}{name, arguments, trans_data\optional{, trans_file}}
Filter using a function taking the name and a string argument. The
return value of the function should be a string. The function will be
passed the entire contents of the input file as a string. The string
return value of the function will become the entire contents of the
transformed file.
\begin{funcdesc}{sponge}{name, file, arguments, trans_data\optional{, trans_file}}
Filter using a function taking the name, the filename, and a string
argument. The return value of the function should be a string. The
function will be passed the entire contents of the input file as a
string. The string return value of the function will become the
entire contents of the transformed file.
\end{funcdesc}
# End

45
Lib/compilerlike.py
View File

@ -7,12 +7,23 @@ behaves as a filter when no argument files are specified on the command
line, but otherwise transforms each file individually into a corresponding
output file.
This module provides framework and glue code to make such programs easy
to write. You supply a function to massage the file data; depending
on which entry point you use, it can take input and output file pointers,
or it can take a string consisting of the entire file's data and return
a replacement, or it can take in succession strings consisting of each
of the file's lines and return a translated line for each.
This module provides framework and glue code to make such programs
easy to write. You supply a function to massage the file data. It
always takes initial name and filename arguments; depending on which
entry point you use, it can also take input and output file pointers,
or it can take a string consisting of the entire file's data and
return a replacement, or it can take in succession strings consisting
of each of the file's lines and return a translated line for each.
The fourth, optional argument of each entry point is a name
transformation function or name suffix string. If it is of string
type, the shortest suffix of each filename beginning with the first
character of the argument string is stripped off. If the first
character of the argument does not occur in the filename, no suffix is
removed. Then the name suffix argument is concatenated to the end of
the stripped filename. (Thus, a name suffix argument of ".x" will
cause the filenames foo.c and bar.d to be transformed to foo.x and
bar.x respectively.)
Argument files are transformed in left to right order in the argument list.
A filename consisting of a dash is interpreted as a directive to read from
@ -25,14 +36,12 @@ and the exception is then passed upwards.
"""
# Requires Python 2.
from __future__ import nested_scopes
import sys, os, filecmp, traceback
def filefilter(name, arguments, trans_data, trans_filename=None):
"Filter stdin to stdout, or file arguments to renamed files."
if not arguments:
trans_data("stdin", sys.stdin, sys.stdout)
trans_data(name, "stdin", sys.stdin, sys.stdout)
else:
for file in arguments:
if file == '-': # - is conventional for stdin
@ -43,7 +52,7 @@ def filefilter(name, arguments, trans_data, trans_filename=None):
tempfile = file + ".~%s-%d~" % (name, os.getpid())
outfp = open(tempfile, "w")
try:
trans_data(file, infp, outfp)
trans_data(name, file, infp, outfp)
except:
os.remove(tempfile)
# Pass the exception upwards
@ -62,26 +71,26 @@ def filefilter(name, arguments, trans_data, trans_filename=None):
else:
os.rename(tempfile, trans_filename(file))
def line_by_line(name, infp, outfp, translate_line):
def line_by_line(name, file, infp, outfp, translate_line):
"Hook to do line-by-line translation for filters."
while 1:
line = infp.readline()
if line == "":
break
elif line: # None returns are skipped
outfp.write(translate_line(name, line))
outfp.write(translate_line(name, file, line))
def linefilter(name, arguments, trans_data, trans_filename=None):
"Filter framework for line-by-line transformation."
return filefilter(name,
arguments,
lambda name, infp, outfp: line_by_line(name, infp, outfp, trans_data),
lambda name, file, infp, outfp: line_by_line(name, file, infp, outfp, trans_data),
trans_filename)
def sponge(name, arguments, trans_data, trans_filename=None):
"Read input sources entire and transform them in memory."
if not arguments:
sys.stdout.write(trans_data(name, sys.stdin.read()))
sys.stdout.write(trans_data(name, "stdin", sys.stdin.read()))
else:
for file in arguments:
infp = open(file)
@ -94,7 +103,7 @@ def sponge(name, arguments, trans_data, trans_filename=None):
sys.stderr.write("%s: can't open tempfile" % name)
return 1
try:
outdoc = trans_data(name, indoc)
outdoc = trans_data(name, file, indoc)
except:
os.remove(tempfile)
# Pass the exception upwards
@ -120,7 +129,7 @@ if __name__ == '__main__':
def nametrans(name):
return name + ".out"
def filefilter_test(name, infp, outfp):
def filefilter_test(name, file, infp, outfp):
"Test hook for filefilter entry point -- put dashes before blank lines."
while 1:
line = infp.readline()
@ -130,11 +139,11 @@ if __name__ == '__main__':
outfp.write("------------------------------------------\n")
outfp.write(line)
def linefilter_test(name, data):
def linefilter_test(name, file, data):
"Test hook for linefilter entry point -- wrap lines in brackets."
return "<" + data[:-1] + ">\n"
def sponge_test(name, data):
def sponge_test(name, file, data):
"Test hook for the sponge entry point -- reverse file lines."
lines = data.split("\n")
lines.reverse()