# CitableParserBuilder: overview

The CitableParserBuilder module offers common functions and data structures for working with citable morphological analyses of citable texts.

At the center of the module are the abstract CitableParser, and the concrete Analysis and AnalyzedToken types.

Parsing functions use a CitableParser to operate either on string values for individual tokens, or on passages of text citable with CTS URNs at the token level. This harmonizes nicely with the Orthography module's functions for tokenizing strings and citable text structures.

Parsing a string value returns a (possibly empty) list of Analysis objects. Parsing a citable passage returns an AnalyzedToken, which pairs the citable passage with the analyses resulting from parsing the passage's text content.

Tip

You can use an OrthographicSystem to create a complete tokenized edition from a citable edition. See the documentation for the Orthography module.

## Shared functions for parsing: the CitableParser abstraction

Subtypes of the CitableParser abstraction must implement the parsetoken function. This enables the CitableParserBuilder module to include concrete implementations of:

• parsewordlist: parse a list of string values
• parsepassage: parse the text component of a CitablePassage as a single token
• parsecorpus: parse the text components of all nodes in a CitableCorpus as individual tokens

## Shared structures: the Analysis and the AnalyzedToken

Every analysis of a string value identifies a valid pairing of a lexeme and a form for the token. The Analysis also includes a stem and rule that explain how the analysis' lexeme and form were arrived at. The structure of an Analysis therefore consists of a string value (the token) and four URN values:

1. the lexeme
2. the morphological form
3. the stem used to arrive at the analysis
4. the inflectional rule used to arrive at the analysis

The AnalyzedToken type associates a Vector of Analysis objects with a citable token.

## Shared functions for working with results of parsing

1. lexemes
2. stringsforlexeme
3. lexemedictionary

## Examples

The following sections illustrate parsing with a sample implementation of a CitableParser designed to parse a corpus of all the known versions of Lincoln's Gettysburg Address, and to identify the form of tokens with the part of speech code used by the Penn treebank project.