In computer science, a lexical grammar or lexical structure is a formal grammar defining the syntax of tokens. The program is written using characters that are defined by the lexical structure of the language used. The character set is equivalent to the alphabet used by any written language. The lexical grammar lays down the rules governing how a character sequence is divided up into subsequences of characters, each part of which represents an individual token. This is frequently defined in terms of regular expressions.[1]
For instance, the lexical grammar for many programming languages specifies that a string literal starts with a " character and continues until a matching " is found (escaping makes this more complicated), that an identifier is an alphanumeric sequence (letters and digits, usually also allowing underscores, and disallowing initial digits), and that an integer literal is a sequence of digits. So in the following character sequence "abc" xyz1 23 the tokens are string, identifier and number (plus whitespace tokens) because the space character terminates the sequence of characters forming the identifier. Further, certain sequences are categorized as keywords – these generally have the same form as identifiers (usually alphabetical words), but are categorized separately; formally they have a different token type.[2]
^Buyya (2009). Object-oriented Programming with Java: Essentials and Applications. Tata McGraw-Hill Education. pp. 57–. ISBN 978-0-07-066908-6.
^James Gosling (2000). The Java Language Specification. Addison-Wesley Professional. pp. 9–. ISBN 978-0-201-31008-5.
In computer science, a lexicalgrammar or lexical structure is a formal grammar defining the syntax of tokens. The program is written using characters...
two differences. First, lexical tokenization is usually based on a lexicalgrammar, whereas LLM tokenizers are usually probability-based. Second, LLM...
Lexical functional grammar (LFG) is a constraint-based grammar framework in theoretical linguistics. It posits two separate levels of syntactic structure...
grammaticalized lexis, and not lexicalizedgrammar. The entire store of lexical items in a language is called its lexis. Lexical items composed of more than...
they act in grammar and compositionality, and the relationships between the distinct senses and uses of a word. The units of analysis in lexical semantics...
identify frequent language patterns (grammar), as well as to have sets of words at their disposal. The lexical method concentrates on teaching fixed...
distinguishing of function/structure words from content/lexical words has been highly influential in the grammar used in second-language acquisition and English-language...
traditional scheme does—include word class, lexical class, and lexical category. Some authors restrict the term lexical category to refer only to a particular...
linguistics a lexical verb or main verb is a member of an open class of verbs that includes all verbs except auxiliary verbs. Lexical verbs typically...
structure, lexical representation, and lexical access. Lawrence Erlbaum Associates, Publishers. ISBN 9780863779268. Geert, Booij (2005). The grammar of words :...
Pattern Grammar is a model for describing the syntactic environments of individual lexical items, derived from studying their occurrences in authentic...
Italian grammar is the body of rules describing the properties of the Italian language. Italian words can be divided into the following lexical categories:...
the syntax of the language is generated by a lexicalgrammar for the words, and a context-free grammar of production rules for the phrases. This is common...
between [ ], / / and ⟨ ⟩, see IPA § Brackets and transcription delimiters. A lexical set is a group of words that share a particular phonological feature. A...
Systemic functional grammar (SFG) is a form of grammatical description originated by Michael Halliday. It is part of a social semiotic approach to language...
theoretical models of different linguists. However, many grammars also draw a distinction between lexical categories (which tend to consist of content words...
situation in a completely different way, namely by using a non-reference lexicalgrammar. Clang's lexer does not attempt to differentiate between type names...
generated from a grammar for the language, though in more complex cases these require manual modification. The lexicalgrammar and phrase grammar are usually...
nouns constitute a lexical category (part of speech) defined according to how its members combine with members of other lexical categories. The syntactic...
the grammar to be used. The choice of syntax is affected by both linguistic and computational concerns; for instance some parsing systems use lexical functional...
Copenhagen Lexical functional grammar, a variety of generative grammar initiated by Joan Bresnan and Ronald Kaplan. Role and reference grammar, a model...
both lexical categories (parts of speech) and phrasal categories. A grammar that uses phrase structure rules is a type of phrase structure grammar. Phrase...
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