TVI

The Vassar Interpreter. A simple interpreter used in CMPU-331

TVI 2.0.0 is a Java implementation of the original C++ interpreter used previously. TVI 2.x supports the same set of opcodes used in the original interpreter. The only differences are:

1. DATA sections are not supported, but the CMPU-331 compiler didn't make use of them anyway.
2. Every instruction must now be numbered sequentially.

Build

To build the interpreter from scratch download the code and compile with Maven.

$> git clone https://github.com/vassar-cmpu-331/TVI.git
$> cd TVI
$> mvn package

If you would like to change the name of the project directory simply specify the name you want git to use when you clone the repository:

$> git clone https://github.com/vassar-cmpu-331/TVI.git my_directory
$> cd my_directory
$> mvn package

The directory my_directory must not already exist.

After running mvn package the generated jar file can be found in the target directory.

Running

Maven generates a runnable jar file that accepts one parameter; the name of the .tvi file to be interpreted (note: you do not have to use a .tvi file extension).

$> java -jar target/tvi-2.0.0.jar /path/to/file.tvi

If the compiled program uses a large amount of memory you may need to increase the size of the Java heap:

$> java -Xmx512M -jar target/tvi-2.0.0.jar /path/to/file.tvi

The -Xmx parameter takes a number followed by the memory unit size (M=megabyte, G=gigabytes). If you forget to include the memory unit size then the default (bytes) is assumed.

Options

TVI accepts the following options:

-t, --trace
Enables tracing. Each instruction is printed to System.out before it is executed
-s, --size
Sets the size of the memory pool the interpreter. The default is 1M memory locations.
NOTE Setting the size of the memory pool is not the same as setting the -Xmx Java command line parameter. Although if you create a very large memory pool you will likely also need to increase the Java heap size.
-d, --debug
Produces some extra debugging output. This is mostly useful for developing TVI itself.
-r, --renumber
Renumbers the statements in a .tvi file. Use this option if you manually add/delte instructions in your .tvi file and need to fix the line numbers after editting.
-v, --version
Displays the TVI version.
-h, --help
Displays a simple help message.

WARNING The --renumber option only renumbers the lines; it DOES NOT back-patch any goto statements; so this option will break your .tvi file if it contains goto statements.

Problems or Bugs

Please open a new issue if (when) you find any bugs in the interpreter.