https://github.com/mittelmark/ptlex
Lexer generator written in Tcl for Tcl, Python, Perl, R and Ruby
https://github.com/mittelmark/ptlex
lexer lexer-parser
Last synced: 7 months ago
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Lexer generator written in Tcl for Tcl, Python, Perl, R and Ruby
- Host: GitHub
- URL: https://github.com/mittelmark/ptlex
- Owner: mittelmark
- License: bsd-3-clause
- Created: 2024-03-16T05:15:49.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-03-19T05:57:55.000Z (about 2 years ago)
- Last Synced: 2025-04-01T02:58:53.435Z (about 1 year ago)
- Topics: lexer, lexer-parser
- Language: Tcl
- Homepage:
- Size: 42 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# ptlex
## NAME
__ptlex__: Lexer generator written in Tcl for Tcl, Python, Perl, R and Ruby
## SYNOPSIS
```
ptlex --lang LANGUAGE ?-+? FLEXFILE OUTFILE
```
Reads the input FLEXFILE and creates a Script OUTFILE for the given language.
The option `-+` allows you to create an object oriented scanner for the given
language. Possible languages are currently Tcl, Perl, Python, Ruby. For Tcl,
Perl and Python as well object oriented lexers can be generated.
## DESCRIPTION
Parsing of various input file formats is a challenging part for programmers.
Lexers simplify this process by providing a simplified file format to generate
a full program using the lexer generator. Here an example for a wc-program
using the ptlex program first for Tcl:
```
%{
global nline nword nchar
set nline 0
set nword 0
set nchar 0
%}
%option buffersize=1024
%%
\n {
incr nline
incr nchar
}
[^ \t\n]+ {
incr nword
incr nchar [string length $yytext]
}
. {
incr nchar
}
%%
if {[llength $argv] == 0} {
puts stderr "usage wc.tcl inputfile"
exit 0
}
yylex [lindex $argv 0]
puts [format "%7d %7d %7d %s" $nline $nword $nchar [lindex $argv 0]]
```
This flex-like input file can be translated into a program with the following programm call:
```
ptlex --lang Tcl wc.ftl wc.tcl
```
If you would like to have a scanner which does not write to stdout you should
remove the commandline parsing at the bottom and just source this file into
your application. There you then have to call yylex with the file which you
would like to use.
For more examples see the folder [samples](samples). You can see the commands
to convert these flex-like input files into programs in the
[Makefile](Makefile).
## INSTALLATION
On Unix systems or on Windows with Msys:
- download the file `ptlex.tapp`
- make it executable using `chmod`
- copy it to a folder belonging to your `PATH` variable
## SUPPORTED LANGUAGES
Scanner generation is done using the Tcl programming language. Scanners can be
generated for the programming languages Tcl, Perl, Python, R and Ruby. For the
first three as well in an OO-style. See the following summary table.
| Programming Language | Functional-Style | OO-style | Samples |
|:--------------------:|:----------------:|:----------:|:------------:|
| Perl | yes | yes | wc, rep, sbs |
| Python 3 | yes | yes | wc, rep, sbs |
| R | yes | no | wc, rep |
| Ruby | yes | no | wc, rep, sbs |
| Tcl | yes | yes (itcl) | wc, rep, sbs |
## OTHER LEXERS
| Lexer | Programming Language | Link |
|:---------------------|:---------------------|:--------------------------------------|
| Flex | C/C++ | https://github.com/westes/flex |
| Gplex | C# | https://github.com/k-john-gough/gplex |
| Jflex | Java | https://github.com/jflex-de/jflex |
| Tply | Pascal | https://github.com/martok/fpc-tply |
| Fickle | Tcl | https://github.com/devnull42/fickle |
| Yeti | Tcl | https://github.com/mittelmark/yeti |
## LICENSE
```
BSD 3-Clause License
Copyright (c) 2009-2024, Detlef Groth, University of Potsdam, Germany
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
```