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author | Martin Robinson <mrobinson@igalia.com> | 2023-06-24 13:38:11 +0200 |
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committer | Martin Robinson <mrobinson@igalia.com> | 2023-06-30 09:51:31 +0200 |
commit | 8be014ee46077e78db21c5d73058c35a4ee65fa9 (patch) | |
tree | 9bfd0bc11997381d792fd3015add8be9cd7abd70 /third_party/ply/example/BASIC/basic.py | |
parent | 7412e28349237055652a08a2216043d0993a3cea (diff) | |
download | servo-8be014ee46077e78db21c5d73058c35a4ee65fa9.tar.gz servo-8be014ee46077e78db21c5d73058c35a4ee65fa9.zip |
Create a top-level "third_party" directory
This directory now contains third_party software that is vendored into
the Servo source tree. The idea is that it would eventually hold
webrender and other crates from mozilla-central as well with a standard
patch management approach for each.
Diffstat (limited to 'third_party/ply/example/BASIC/basic.py')
-rw-r--r-- | third_party/ply/example/BASIC/basic.py | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/third_party/ply/example/BASIC/basic.py b/third_party/ply/example/BASIC/basic.py new file mode 100644 index 00000000000..70ac9e7c740 --- /dev/null +++ b/third_party/ply/example/BASIC/basic.py @@ -0,0 +1,65 @@ +# An implementation of Dartmouth BASIC (1964) +# + +import sys +sys.path.insert(0, "../..") + +if sys.version_info[0] >= 3: + raw_input = input + +import basiclex +import basparse +import basinterp + +# If a filename has been specified, we try to run it. +# If a runtime error occurs, we bail out and enter +# interactive mode below +if len(sys.argv) == 2: + data = open(sys.argv[1]).read() + prog = basparse.parse(data) + if not prog: + raise SystemExit + b = basinterp.BasicInterpreter(prog) + try: + b.run() + raise SystemExit + except RuntimeError: + pass + +else: + b = basinterp.BasicInterpreter({}) + +# Interactive mode. This incrementally adds/deletes statements +# from the program stored in the BasicInterpreter object. In +# addition, special commands 'NEW','LIST',and 'RUN' are added. +# Specifying a line number with no code deletes that line from +# the program. + +while 1: + try: + line = raw_input("[BASIC] ") + except EOFError: + raise SystemExit + if not line: + continue + line += "\n" + prog = basparse.parse(line) + if not prog: + continue + + keys = list(prog) + if keys[0] > 0: + b.add_statements(prog) + else: + stat = prog[keys[0]] + if stat[0] == 'RUN': + try: + b.run() + except RuntimeError: + pass + elif stat[0] == 'LIST': + b.list() + elif stat[0] == 'BLANK': + b.del_line(stat[1]) + elif stat[0] == 'NEW': + b.new() |