Understanding the Differences Between the File Parsing Tools

There are three tools available to perform file parsing. Depending on the file parsing that you want to perform, it may be more beneficial to choose one over the other.

The following parsing components are available:

  • Data Exchanger. The Data Exchanger supports directly parsing name/value files, tables of data, and vectors of numbers. You can use the Data Exchanger to parse instructions to be augmented with arbitrary Java code through the Dynamic Java interpreter.

  • iSIGHT File Parser. The iSIGHT File Parser uses a simplified language, similar to TCL, to specify parsing instructions. You can use the File Parser to program complex parses.

  • Fast Parser. The Fast Parser is a simple and fast parser, especially for inserting parameters into input files. While the Fast Parser can read fixed-length columns of numbers, it has no programming facilities for conditional or looping operations.

In general, the Data Exchanger is recommended for new models because it is the most powerful parsing tool. You can use the iSIGHT File Parser and the Fast Parser to convert iSIGHT models to Isight. The same parsing instructions can be used in both models, and you can directly import the parsing instructions or template files from an iSIGHT model into an Isight model.

The Fast Parser is the simplest to use of the three parsers, and can read large output files rapidly if you are selecting text from only a small portion of the file. When preparing input files, it can be much easier to use the Fast Parser than the other parsers—you specify the parameter and select the location to write the value and you do not need to specify how that location is found. The Fast Parser can also read (and, with limitations, write) columns of numbers in one simple action. However, the numbers must be in the same relative position on successive lines because there is no way to skip lines. Only fixed-length columns are supported.

You may also find the Fast Parser useful for new models, if the parsing fits within the Fast Parser’s limitations. While the Fast Parser can support files of unlimited size at run time, the editor can support only about a 4.5 MB template file. To read larger files, you have to use an external editor to edit the file down to just the sections of interest, and use the smaller file as the template.

It is possible to mix the parsers in the same model. You can also use any of the parsers in the Simcode component, though a given Simcode can use only one of the parsers and must use the same parser type for the input and output parse. By mapping a file parameter between parsing components, you can even process the same file using multiple parsers, taking advantage of what each parser does best. For example, you can prepare a portion of an input file using the iSIGHT File Parser and insert it into the Fast Parser using the Include a File option. On the output side, you can extract part of the output data using the Fast Parser and another part using the iSIGHT File Parser.