A parse tree or parsing tree[1] or derivation tree or concrete syntax tree is an ordered, rooted tree that represents the syntactic structure of a string according to some context-free grammar. The term parse tree itself is used primarily in computational linguistics; in theoretical syntax, the term syntax tree is more common.
Concrete syntax trees reflect the syntax of the input language, making them distinct from the abstract syntax trees used in computer programming. Unlike Reed-Kellogg sentence diagrams used for teaching grammar, parse trees do not use distinct symbol shapes for different types of constituents.
Parse trees are usually constructed based on either the constituency relation of constituency grammars (phrase structure grammars) or the dependency relation of dependency grammars. Parse trees may be generated for sentences in natural languages (see natural language processing), as well as during processing of computer languages, such as programming languages.
A related concept is that of phrase marker or P-marker, as used in transformational generative grammar. A phrase marker is a linguistic expression marked as to its phrase structure. This may be presented in the form of a tree, or as a bracketed expression. Phrase markers are generated by applying phrase structure rules, and themselves are subject to further transformational rules.[2] A set of possible parse trees for a syntactically ambiguous sentence is called a "parse forest."[3]
^See Chiswell and Hodges 2007: 34.
^Noam Chomsky (26 December 2014). Aspects of the Theory of Syntax. MIT Press. ISBN 978-0-262-52740-8.
^Billot, Sylvie, and Bernard Lang. "The structure of shared forests in ambiguous parsing."
A parsetree or parsingtree or derivation tree or concrete syntax tree is an ordered, rooted tree that represents the syntactic structure of a string...
information.[citation needed] Some parsing algorithms generate a parse forest or list of parsetrees from a string that is syntactically ambiguous. The term is...
practice, e.g. by a recursive descent parser. Unlike CFGs, PEGs cannot be ambiguous; a string has exactly one valid parsetree or none. It is conjectured that...
parsers: SLR parsers, LALR parsers, canonical LR(1) parsers, minimal LR(1) parsers, and generalized LR parsers (GLR parsers). LR parsers can be generated...
s,a] = <p,b,c> if P[n,1,1] > 0 then find the parsetree by retracing through back return the parsetree else return "not a member of language" In informal...
(A)? A A → /* some rule */ to one descent into A. If a parser builds a parsetree during a parse, it must memoize not only the length of the input that...
recogniser can be modified to create a parsetree as it recognises, and in that way can be turned into a parser. In the following descriptions, α, β, and...
output, typically a parsetree or a set of indices representing locations in the string where parsing stopped successfully. Parser combinators enable a...
operation (store) and one binary operation (plus) that together make up a parsetree that calculates a number. 8.2 The PORS Language, Page 215, Evolutionary...
computer science, an LL parser (Left-to-right, leftmost derivation) is a top-down parser for a restricted context-free language. It parses the input from Left...
there exists a string that can have more than one leftmost derivation or parsetree. Every non-empty context-free language admits an ambiguous grammar by...
(mathematics) Term (logic) Context-free grammar Parsetree Abstract syntax tree Bruno R. Preiss (1998). "Expression Trees". Archived from the original on January...
evaluating, and parsing as building a concrete syntax tree (CST, parsetree) and then transforming it into an abstract syntax tree (AST, syntax tree). In some...
certain parsetree can be considered theorems that follow from these axioms. This has the advantage of making it so that recognition and parsing of expressions...
BSP tree Rapidly exploring random tree Abstract syntax treeParsetree Decision tree Alternating decision tree Minimax tree Expectiminimax tree Finger...
characters can serve other purposes (e.g., marking abbreviations). Parsing Determine the parsetree (grammatical analysis) of a given sentence. The grammar for...
complete parse for a sentence. (The probability associated with a grammar rule may be induced, but the application of that grammar rule within a parsetree and...
of the language is ambiguous, meaning there is more than one correct parsetree. In many programming languages one may write conditionally executed code...
break it down part by part and look at its analyzed form (known as its parsetree in computer science, and as its deep structure in generative grammar)...
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