Lttoolbox

lttoolbox is a toolbox for lexical processing, morphological analysis and generation of words. The analysis is the process of splitting of words splitting a word (e.g. cats) into its lemma 'cat' and the grammatical information <n><pl>. The generation is the opposite process.

The package is split into three programs, lt-comp, the compiler, lt-proc, the processor, and lt-expand, which generates all possible mappings between surface forms and lexical forms in the dictionary.

Creation

Main article: Monodix basics

Morphological analyser specification files, or morphological dictionaries may be found in all of our language pair packages, from the incubator, or you may elect to create your own (more instructions at the page Monodix basics). You can also check out our list of dictionaries, which has statistics on names, locations and number of entries of each of the dictionaries.

Usage

Compilation

Compilation into the binary format is achieved by means of the lt-comp program. You can compile a given .dix from left-to-right (LR), or from right-to-left (RL). Compiling LR usually creates an analyser, compiling RL usually creates a generator.

Example

Compile the apertium-es-ca.ca.dix dictionary in a left-to-right manner into the binary ca.bin.

$ lt-comp lr apertium-es-ca.ca.dix ca.bin

Processing

There are two main modes of use for the processor (lt-proc), analysis (which is the default mode) and generation. Analysis converts surface forms into the set of possible lexical forms, while generation converts a lexical form into the corresponding surface form.

Analysis

After compiling the apertium-es-ca.ca.dix file left-to-right into ca.morf.bin, we can analyse Catalan:

Example

$ echo "prova" | lt-proc ca.morf.bin

^prova/prova<n><f><sg>/provar<vblex><pri><p3><sg>/provar<vblex><imp><p2><sg>$

Generation

And compiling it right-to-left, we can generate:

Example

$ echo "^prova<n><f><pl>$"  | lt-proc -g ca.gen.bin

proves

Expansion

Sometimes you want to be able to see the complete output of the dictionary. That is, all of the mappings between lexical and surface forms. For this you can use the lt-expand tool. This output is often useful in finding bugs in assignment of paradigms etc.

Example

The command to expand the Catalan dictionary in the apertium-es-ca pair, along with the first 10 lines of output, at the last count the total length of the output was over 2.3 million lines.

$ lt-expand apertium-es-ca.ca.dix 

abdominals:abdominal<adj><mf><pl>
abdominal:abdominal<adj><mf><sg>
absents:absent<adj><mf><pl>
absent:absent<adj><mf><sg>
absolutes:absolut<adj><f><pl>
absoluta:absolut<adj><f><sg>
absoluts:absolut<adj><m><pl>
absolut:absolut<adj><m><sg>
abstractes:abstracte<adj><mf><pl>
abstracta:abstracte<adj><f><sg>

Note

You cannot run lt-expand directly on the dix.xml file. The dix files in (for example) the cy-en pair have their symbols in a separate file. You need to first run xmllint:

$ xmllint --xinclude apertium-cy-en.cy.dix.xml > apertium-cy-en.cy.dix

Then run lt-expand on the apertium-cy-en.cy.dix file, redirecting the output into a text file:

lt-expand apertium-cy-en.cy.dix > cy.dix.expanded.txt

Troubleshooting

Empty left side

If you get a message like:

Error: Invalid dictionary (hint: the left side of an entry is empty)

Try searching for empty left sides in your dictionary by using lt-expand and grep. For example in the Icelandic dictionary,

$ lt-expand apertium-fo-is.is.dix  | grep ^:
:kunna<vblex><imp><p2><sg>
:kunna<vblex><imp><p1><pl>
:kunna<vblex><imp><p2><pl>

The empty left side will look something like:

      <e>
        <p>
          <l></l>
          <r>kunna<s n="vblex"/><s n="imp"/><s n="p2"/><s n="pl"/></r>
        </p>
      </e>

It is not possible to have an empty left side in a paradigm if you have no invariant (<i>) section in the main section entry, e.g.

    <e lm="kunna"><i></i><par n="/kunna__vblex"/></e>

This means you should go and look for the "kunna" verb and see where the empty left side is, and put something there, or add something to the invariant section.

See also

• Monodix basics