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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 /components/script/dom/bindings/codegen/ply/example/BASIC/README | |
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 'components/script/dom/bindings/codegen/ply/example/BASIC/README')
-rw-r--r-- | components/script/dom/bindings/codegen/ply/example/BASIC/README | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/components/script/dom/bindings/codegen/ply/example/BASIC/README b/components/script/dom/bindings/codegen/ply/example/BASIC/README deleted file mode 100644 index be24a3005e7..00000000000 --- a/components/script/dom/bindings/codegen/ply/example/BASIC/README +++ /dev/null @@ -1,79 +0,0 @@ -Inspired by a September 14, 2006 Salon article "Why Johnny Can't Code" by -David Brin (http://www.salon.com/tech/feature/2006/09/14/basic/index.html), -I thought that a fully working BASIC interpreter might be an interesting, -if not questionable, PLY example. Uh, okay, so maybe it's just a bad idea, -but in any case, here it is. - -In this example, you'll find a rough implementation of 1964 Dartmouth BASIC -as described in the manual at: - - http://www.bitsavers.org/pdf/dartmouth/BASIC_Oct64.pdf - -See also: - - http://en.wikipedia.org/wiki/Dartmouth_BASIC - -This dialect is downright primitive---there are no string variables -and no facilities for interactive input. Moreover, subroutines and functions -are brain-dead even more than they usually are for BASIC. Of course, -the GOTO statement is provided. - -Nevertheless, there are a few interesting aspects of this example: - - - It illustrates a fully working interpreter including lexing, parsing, - and interpretation of instructions. - - - The parser shows how to catch and report various kinds of parsing - errors in a more graceful way. - - - The example both parses files (supplied on command line) and - interactive input entered line by line. - - - It shows how you might represent parsed information. In this case, - each BASIC statement is encoded into a Python tuple containing the - statement type and parameters. These tuples are then stored in - a dictionary indexed by program line numbers. - - - Even though it's just BASIC, the parser contains more than 80 - rules and 150 parsing states. Thus, it's a little more meaty than - the calculator example. - -To use the example, run it as follows: - - % python basic.py hello.bas - HELLO WORLD - % - -or use it interactively: - - % python basic.py - [BASIC] 10 PRINT "HELLO WORLD" - [BASIC] 20 END - [BASIC] RUN - HELLO WORLD - [BASIC] - -The following files are defined: - - basic.py - High level script that controls everything - basiclex.py - BASIC tokenizer - basparse.py - BASIC parser - basinterp.py - BASIC interpreter that runs parsed programs. - -In addition, a number of sample BASIC programs (.bas suffix) are -provided. These were taken out of the Dartmouth manual. - -Disclaimer: I haven't spent a ton of time testing this and it's likely that -I've skimped here and there on a few finer details (e.g., strictly enforcing -variable naming rules). However, the interpreter seems to be able to run -the examples in the BASIC manual. - -Have fun! - --Dave - - - - - - |