Daki is a small computer programming language influenced by Prolog and Datalog. Read all about it.
For fast prototyping and iteration, this first interpreter is written in Ruby.
You will only require a not-too-old Ruby binary.
The Daki interpreter can be used both in interactive and non-interactive mode. In non-interactive mode, the interpreter input, read from files, is also outputted so as to mimic what would appear on a terminal on interactive mode.
In non-interactive mode, the interpreter reads one or more text files in sequence, and interpretes each line fully before advancing. A line can change the global state, which consists of logical assertions.
To launch the interpreter in interactive mode, use the -i flag:
./dakilang -iIn non-interactive mode a syntax error will end the program, whereas nothing is stopped in interactive mode, so give it a go in interactive mode until you have a good grasp of the syntax.
To launch the interpreter in non-interactive mode, use -c with the file path to be executed:
./dakilang -c examples/example1.dlYou can mix the modes, you can start the interpreter by including - consulting - one or more files, and afterwards switching to interactive mode:
./dakilang -i -c examples/example1.dl -c examples/example2.dlSwitching to interactive mode is always performed only after every consulted file is interpreted, in order.
The full list of command line options are:
| Option | Description |
|---|---|
| -h, --help | Print out the program manual and exit |
| -v, --version | Print out the program name and version, and exit |
| -c, --consult | Read file with path F and interpret each line |
| -i, --interactive | Activate interactive mode after finishing consulting all files |
| -d, --debug | Activate debug mode, which shows the output of the output of clause parsing and a trace of the query solver |
| -t, --time | Changes the default query timeout time; N is a floating point value in seconds |
| --disable-colors | Disable the use of colors in the interpreter's output |
This interpreter has tests for the interpreter search algorithm itsef, and for the parser:
./test_interpreter.sh
./test_parser.shIf you find a bug, or the interpreter crashes, please open an issue with the faulty instructions.
To debug the interpreter itself, first make sure the Ruby gem pry is installed system-wide:
gem install pryThen plant a binding.pry instruction where you need a breakpoint, and start the interpreter from inside the src/ folder:
cd src
ruby dakilang.rb -c ../program_to_debug.dlCopyright (c) 2021 Gonçalo Mendes Ferreira
Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
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