Guile Mecab

Guile bindings for MeCab, yet another part-of-speech and morphological analyzer. The bindings link to libmecab and offer a small API for using MeCab.

Installation

Using Guix, it is easy to use and install mecab, as we provide a recipe for mecab, mecab-ipadic (one possible dictionary for Japanese) and guile-mecab in the guix directory. For instance, to enter an environment with all the tools needed to run guile-mecab, you can run, from this repository:

guix environment -L guix --ad-hoc guile guile-mecab mecab-ipadic

Usage

Once installed, you can use the bindings by loading (mecab mecab) in a guile program.

• Scheme Procedure: mecab-version Returns MeCab's version number.

The tagger

The tagger is a global object used to load a dictionary. You can create and remove a tagger by using the following procedures:

• Scheme Procedure: mecab-new-tagger [args '()]

  This procedure creates a new tagger that can be passed to other functions. args is a list of strings that represent the arguments passed to mecab. See mecab's help for a list of accepted arguments.

• Scheme Procedure: mecab-destroy tagger

  This procedure destroys a tagger. Reusing it afterwards will not work, and may lead to a segmentation fault.

• Scheme Procedure: mecab-error tagger

  Returns a string representing the last error message returned by the tagger.

The analysis

To analyse a sentence, you can use one of the following procedures.

• Scheme Procedure: mecab-parse tagger str

  Parses a sentence str with tagger and returns a node.

• Scheme Procedure: mecab-parse-to-str tagger str

  Parses a sentence str with tagger and returns a string containing the result. The resulting string can be affected by options such as -O or --node-format.

• Scheme Procedure: mecab-split tagger str

  Returns the list of words in str.

• Scheme Procedure: mecab-features tagger str

  Returns the list of features associated with each word in str, in the same order as mecab-split. Note that the strings are always in CSV format, and this cannot be affected by the -O, --node-format etc. options.

• Scheme Procedure: mecab-words tagger str

  Returns the list of words in dictionary form that are present in str, leaving out punctuation and declension.

Nodes

Nodes can be manipulated with the following procedures.

• Scheme Procedure: node-feature node

  Return the feature string of the given node.

• Scheme Procedure: node-surface node

  Return the surface value of the given node, that is the word as it is written in the sentence (not necessarily its dictionary form). Note that this function is not very reliable.

• Scheme Procedure: node-stat node

  Return the type of the given node. The value is a number which is one of MECAB_NOR_NODE, MECAB_UNK_NODE, MECAB_BOS_NODE, MECAB_EOS_NODE or MECAB_EON_NODE.

• Scheme Procedure: node-next node

  Return the node following the given node.

• Scheme Procedure: node-prev node

  Return the node preceding the given node.