Merging in removal of this file from branch to trunk.

Lib/compilerlike.py

-"""
-compilerlike -- framework code for building compiler-like programs.
-
-There is a common `compiler-like' pattern in Unix scripts which is useful
-for translation utilities of all sorts.  A program following this pattern
-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.  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
-standard input (this can be useful in pipelines).
-
-Replacement of each file is atomic and doesn't occur until the
-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.
-"""
-
-# Requires Python 2.
-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(name, "stdin", sys.stdin, sys.stdout)
-    else:
-        for file in arguments:
-            if file == '-':             # - is conventional for stdin
-                file = "stdin"
-                infp = sys.stdin
-            else:
-                infp = open(file)
-            tempfile = file + ".~%s-%d~" % (name, os.getpid())
-            outfp = open(tempfile, "w")
-            try:
-                trans_data(name, file, infp, outfp)
-            except:
-                os.remove(tempfile)
-                # Pass the exception upwards
-                (exc_type, exc_value, exc_traceback) = sys.exc_info()
-                raise exc_type, exc_value, exc_traceback
-            if filecmp.cmp(file, tempfile):
-                os.remove(tempfile)
-            else:
-                if not trans_filename:
-                    os.rename(tempfile, file)
-                elif type(trans_filename) == type(""):
-                    i = file.rfind(trans_filename[0])
-                    if i > -1:
-                        file = file[:i]
-                    os.rename(tempfile, stem + trans_filename)
-                else:
-                    os.rename(tempfile, trans_filename(file))
-
-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, file, line))
-
-def linefilter(name, arguments, trans_data, trans_filename=None):
-    "Filter framework for line-by-line transformation."
-    return filefilter(name,
-                  arguments,
-                  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, "stdin", sys.stdin.read()))
-    else:
-        for file in arguments:
-            infp = open(file)
-            indoc = infp.read()
-            infp.close()
-            tempfile = file + ".~%s-%d~" % (name, os.getpid())
-            try:
-                outfp = open(tempfile, "w")
-            except OSError:
-                sys.stderr.write("%s: can't open tempfile" % name)
-                return 1
-            try:
-                outdoc = trans_data(name, file, indoc)
-            except:
-                os.remove(tempfile)
-                # Pass the exception upwards
-                (exc_type, exc_value, exc_traceback) = sys.exc_info()
-                raise exc_type, exc_value, exc_traceback
-            if outdoc == indoc:
-                os.remove(tempfile)
-            else:
-                outfp.write(outdoc)
-                if not trans_filename:
-                    os.rename(tempfile, file)
-                elif type(trans_filename) == type(""):
-                    i = file.rfind(trans_filename[0])
-                    if i > -1:
-                        file = file[:i]
-                    os.rename(tempfile, file + trans_filename)
-                else:
-                    os.rename(tempfile, trans_filename(file))
-
-if __name__ == '__main__':
-    import getopt
-
-    def nametrans(name):
-        return name + ".out"
-
-    def filefilter_test(name, file, infp, outfp):
-        "Test hook for filefilter entry point -- put dashes before blank lines."
-        while 1:
-            line = infp.readline()
-            if not line:
-                break
-            if line == "\n":
-                outfp.write("------------------------------------------\n")
-            outfp.write(line)
-
-    def linefilter_test(name, file, data):
-        "Test hook for linefilter entry point -- wrap lines in brackets."
-        return "<" + data[:-1] + ">\n"
-
-    def sponge_test(name, file, data):
-        "Test hook for the sponge entry point -- reverse file lines."
-        lines = data.split("\n")
-        lines.reverse()
-        return "\n".join(lines)
-
-    (options, arguments) = getopt.getopt(sys.argv[1:], "fls")
-    for (switch, val) in options:
-        if switch == '-f':
-            filefilter("filefilter_test", arguments, filefilter_test,nametrans)
-        elif switch == '-l':
-            linefilter("linefilter_test", arguments, linefilter_test,nametrans)
-        elif switch == '-s':
-            sponge("sponge_test", arguments, sponge_test, ".foo")
-        else:
-            print "Unknown option."
-
-# End