* Ruby ( similarly, it uses an abstract syntax tree as intermediate representation )

Macro systems that work at the level of abstract syntax trees are called syntactic macros and preserve the lexical structure of the original program.

When Polish notation is used as a syntax for mathematical expressions by interpreters of programming languages, it is readily parsed into abstract syntax trees and can, in fact, define a one-to-one representation for the same.

** and RefactoringNG, a Netbeans module for refactoring where you can write transformations rules of the program's abstract syntax tree.

Most operator-precedence parsers can be modified to produce postfix expressions ; in particular, once an abstract syntax tree has been constructed, the corresponding postfix expression is given by a simple post-order traversal of that tree.

Other linguists ( e. g. Gerald Gazdar ) take a more Platonistic view, since they regard syntax to be the study of an abstract formal system.

SGML provides an abstract syntax that can be implemented in many different types of concrete syntax.

The following example shows how to use Bison and flex to write a simple calculator program ( only addition and multiplication ) and a program for creating an abstract syntax tree.

An interpreter might well use the same lexical analyzer and parser as the compiler and then interpret the resulting abstract syntax tree.

Depending upon the type of parser that should be generated, these routines may construct a parse tree ( or abstract syntax tree ), or generate executable code directly.

The abstract syntax of data is its structure described as a data type ( possibly, but not necessarily, an abstract data type ), independent of any particular representation or encoding.

To be implemented either for computation or communications, a mapping from the abstract syntax to specific machine representations and encodings must be defined ; these may be called the " concrete syntax " ( in language implementation ) or the " transfer syntax " ( in communications ).

A compiler's internal representation of a program will typically be specified by an abstract syntax in terms of categories such as " statement ", " expression " and " identifier ".

A parse tree is similar to an abstract syntax tree but it will typically also contain features such as parentheses which are syntactically significant but which are implicit in the structure of the abstract syntax tree.

Algebraic data types are particularly well-suited to the implementation of abstract syntax.

* Higher-order abstract syntax

ASN. 1 defines the abstract syntax of information but does not restrict the way the information is encoded.

These commentators speak thus: For example, a particular tree, with a branch or two missing, possibly alive, possibly dead, and with the initials of two lovers carved into its bark, is distinct from the abstract form of Tree-ness.

In computer science, an abstract syntax tree ( AST ), or just syntax tree, is a tree representation of the abstract syntactic structure of source code written in a programming language.

* AST View: an Eclipse plugin to visualize a Java abstract syntax tree

The implementation of Perl and Ruby 1. 8 instead work by walking an abstract syntax tree representation derived from the source code.

The input to the code generator typically consists of a parse tree or an abstract syntax tree.

for this division is but an abstract representation of the social struggle between mysticism and science.

But he would fight for his own liberty rather than for any abstract principle connected with it -- such as `` cause ''.

The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny quantities has been around for millennia, but these ideas were founded in abstract, philosophical reasoning rather than experimentation and empirical observation.

In abstract algebra, an algebraically closed field F contains a root for every non-constant polynomial in F, the ring of polynomials in the variable x with coefficients in F.

In the context of abstract algebra, for example, a mathematical object is an algebraic structure such as a group, ring, or vector space.

Alaric displayed similar wisdom in political affairs by appointing a commission to prepare an abstract of the Roman laws and imperial decrees, which would form the authoritative code for his Roman subjects.

Pobedonostsev awakened in his pupil little love of abstract study or prolonged intellectual exertion, but instilled into the young man's mind the belief that zeal for Russian Orthodox thought was an essential factor of Russian patriotism to be cultivated by every right-minded emperor.

If we take in our hand any volume ; of divinity or school metaphysics, for instance ; let us ask, Does it contain any abstract reasoning concerning quantity or number?

He is also noted for his mastery of abstract approaches to mathematics and his perfectionism in matters of formulation and presentation.

In computer science, an abstract data type ( ADT ) is a mathematical model for a certain class of data structures that have similar behavior ; or for certain data types of one or more programming languages that have similar semantics.

The notion of abstract data types is related to the concept of data abstraction, important in object-oriented programming and design by contract methodologies for software development.

xiii, " Cum ad Sacrosanctae Romanae Ecclesiae ") prescribes their work, determines how much they may charge for their labour, fixes a certain tax for an abstract or abridgment of twenty-five words, or their equivalent, 150 letters, forbids them to charge more, even though the abstract goes over twenty-five words but less than fifty words, enacts that the basis of the tax is the labour employed in writing, expediting, etc., the Bulls, and by no means the emoluments accruing to the recipient of the favour or benefice conferred by the Bull, and declares that whoever shall charge more than the tax fixed by him shall be suspended for six months from office, and upon a second violation of the law, shall be deprived of it altogether, and if the delinquent be an abbreviator, he shall be excommunicated.

The oldest known physical representations identified as symbols for abstract concepts are abstract engravings found on two pieces of ochre in Blombos Cave, South Africa, in 2001.

This is true for all verbal / abstract communication.

An abstraction can be seen as a process of mapping multiple different pieces of constituent data to a single piece of abstract data based on similarities in the constituent data, for example many different physical cats map to the abstraction " CAT ".

A recent meta-analysis suggests that the verbal system has greater engagement for abstract concepts when the perceptual system is more engaged for processing of concrete concepts.

The following properties of integer addition serve as a model for the abstract group axioms given in the definition below.

To appropriately understand these structures as a collective, the following abstract definition is developed.

Sadleir's interest in Kandinsky also led to Kandinsky's first works entering a British art collection ; Sadleir's father, Michael Sadler, acquired several woodprints and the abstract painting Fragment for Composition VII in 1913 following a visit by father and son to meet Kandinsky in Munich that year.

" Mill's low reputation as a philosopher of logic, and the low estate of empiricism in the century and a half following him, derives from this failed attempt to link abstract thoughts to the physical world, when it is obvious that abstraction consists precisely of separating the thought from its physical foundations.

Cunningham later re-edited the video in 2002, following his disappointment with the original: " It was intended to be completely abstract but it didn't quite work out that way ".

All the following rounding modes are concrete implementations of the abstract single-argument " round ()" function presented and used in the previous sections.

When asked about this, instead of following this pattern of thinking, the Buddha attacks it at its very root: the notion of a principle in the abstract, superimposed on experience.

When asked about this, instead of following this pattern of thinking, the Buddha attacks it at its very root: the notion of a principle in the abstract, superimposed on experience.

An abstract coverage consists of the following components:

In the 1840s, academic philosophy in Europe, following Hegel, was almost completely divorced from the concerns of individual human life, in favour of pursuing abstract metaphysical systems.

In group theory, a branch of abstract algebra, the Whitehead problem is the following question:

More abstract examples include the following:

" The issue of choosing between very abstract and very specific instruction can be viewed in the following way.

The definition of candidate keys can be illustrated with the following ( abstract ) example.

In the following weeks, Dick experienced further visions, including a hallucinatory slideshow of abstract patterns and an information-rich beam of pink light.

There was a brief flowering of English progressive folk in the late 1960s and early 1970s, with groups like the Third Ear Band and Quintessence following the eastern Indian musical and more abstract work by group such as Comus, Dando Shaft, The Trees, Spirogyra, Forest, and Jan Dukes De Grey, but commercial success was elusive for these bands and most had broken up or moved in very different directions by about 1973.

The vanguard in culturally conservative Argentina, futurists and cubists like Xul Solar and Emilio Pettoruti earned a following as considerable as that of less abstract and more sentimental portrait and landscape painters, like Raúl Soldi.

The abstract syntax for the π-calculus is built from the following BNF grammar ( where x and y are any names from Χ ):

City planners have designated North Halsted an official pedestrian and bike route following a 1998 community project that resulted in the erection of 11 pairs of rainbow-colored abstract Art Deco pylons along the strip.

This section provides a formal mathematical definition of step response in terms of the abstract mathematical concept of a dynamical system: all notations and assumptions required for the following description are listed here.

This sense of finiteness lies behind the following abstract definition:

Rozhenko tells Worf and Picard that he believes offering the Boraalan culture a chance of survival is more important than following the abstract concepts of the Prime Directive.

A monograph on this topic summarizes an extensive amount of published research in this area up to 1986, including subsections in the following areas: computer modeling in biology and medicine, arterial system models, neuron models, biochemical and oscillation networks, quantum automata, quantum computers in molecular biology and genetics, cancer modelling, neural nets, genetic networks, abstract categories in relational biology, metabolic-replication systems, category theory applications in biology and medicine, automata theory, cellular automata, tessellation models and complete self-reproduction, chaotic systems in organisms, relational biology and organismic theories.