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Ragel

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Ragel is a finite-state machine compiler and a parser generator . Initially Ragel supported output for C , C++ and Assembly source code, later expanded to support several other languages including Objective-C , D , Go , Ruby , and Java . Additional language support is also in development. It supports the generation of table or control flow driven state machines from regular expressions and/or state charts and can also build lexical analysers via the longest-match method. Ragel specifically targets text parsing and input validation .

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23-410: Ragel supports the generation of table or control flow driven state machines from regular expressions and/or state charts and can also build lexical analysers via the longest-match method. A unique feature of Ragel is that user actions can be associated with arbitrary state machine transitions using operators that are integrated into the regular expressions. Ragel also supports visualization of

46-401: A hyponym is subordinate to a hypernym. An animal is a generalization of a mammal , a bird, a fish, an amphibian and a reptile. Generalization has a long history in cartography as an art of creating maps for different scale and purpose. Cartographic generalization is the process of selecting and representing information of a map in a way that adapts to the scale of the display medium of

69-431: A limited space and therefore they are popular in scientific literature in many fields of study. As a communication tool, a table allows a form of generalization of information from an unlimited number of different social or scientific contexts. It provides a familiar way to convey information that might otherwise not be obvious or readily understood. For example, in the following diagram, two alternate representations of

92-419: A matter of custom or formal convention. Modern software applications give users the ability to generate, format, and edit tables and tabular data for a wide variety of uses, for example: Tables have uses in software development for both high-level specification and low-level implementation. Usage in software specification can encompass ad hoc inclusion of simple decision tables in textual documents through to

115-447: Is a simplified description of the most basic kind of table. Certain considerations follow from this simplified description: The elements of a table may be grouped, segmented, or arranged in many different ways, and even nested recursively . Additionally, a table may include metadata , annotations , a header, a footer or other ancillary features. The following illustrates a simple table with four columns and nine rows. The first row

138-409: Is meant to be context-specific. That is to say, correctly generalized maps are those that emphasize the most important map elements, while still representing the world in the most faithful and recognizable way. The level of detail and importance in what is remaining on the map must outweigh the insignificance of items that were generalized—so as to preserve the distinguishing characteristics of what makes

161-402: Is not counted, because it is only used to display the column names. This is called a "header row". The concept of dimension is also a part of basic terminology. Any "simple" table can be represented as a "multi-dimensional" table by normalizing the data values into ordered hierarchies . A common example of such a table is a multiplication table . In multi-dimensional tables, each cell in

184-652: Is uppercase/lowercase 'e' (to indicate a number in scientific format). As such, it will recognize the following properly: but not: Ragel's input is a regular expression only in the sense that it describes a regular language ; it is usually not written in a concise regular expression, but written out into multiple parts like in Extended Backus–Naur form . For example, instead of supporting POSIX character classes in regex syntax, Ragel implements them as built-in production rules. As with usual parser generators, Ragel allows for handling code for productions to be written with

207-530: The tables were covered with a piece of checkered cloth, to count money. Exchequer is an archaic term for the English institution which accounted for money owed to the monarch . Thus the checkerboard tables of stacks of coins are a concrete realization of this information . Generalization A generalization is a form of abstraction whereby common properties of specific instances are formulated as general concepts or claims. Generalizations posit

230-474: The body of the table (and the value of that cell) relates to the values at the beginnings of the column (i.e. the header), the row, and other structures in more complex tables. This is an injective relation : each combination of the values of the headers row (row 0, for lack of a better term) and the headers column (column 0 for lack of a better term) is related to a unique cell in the table: The first column often presents information dimension description by which

253-423: The concept animal is a generalization of the concept bird , since every bird is an animal, but not all animals are birds (dogs, for instance). For more, see Specialisation (biology) . The connection of generalization to specialization (or particularization ) is reflected in the contrasting words hypernym and hyponym . A hypernym as a generic stands for a class or group of equally ranked items, such as

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276-425: The context. Further, tables differ significantly in variety, structure, flexibility, notation, representation and use. Information or data conveyed in table form is said to be in tabular format ( adjective ). In books and technical articles, tables are typically presented apart from the main text in numbered and captioned floating blocks . A table consists of an ordered arrangement of rows and columns . This

299-548: The development of at least two tabular approaches. At a programming level, software may be implemented using constructs generally represented or understood as tabular, whether to store data (perhaps to memoize earlier results), for example, in arrays or hash tables , or control tables determining the flow of program execution in response to various events or inputs. Database systems often store data in structures called tables; in which columns are data fields and rows represent data records. In medieval counting houses ,

322-451: The existence of a domain or set of elements, as well as one or more common characteristics shared by those elements (thus creating a conceptual model ). As such, they are the essential basis of all valid deductive inferences (particularly in logic , mathematics and science), where the process of verification is necessary to determine whether a generalization holds true for any given situation. Generalization can also be used to refer to

345-433: The generalization. The concept of generalization has broad application in many connected disciplines, and might sometimes have a more specific meaning in a specialized context (e.g. generalization in psychology, generalization in learning ). In general, given two related concepts A and B, A is a "generalization" of B (equiv., B is a special case of A ) if and only if both of the following hold: For example,

368-457: The generated machine via graphviz . The above graph represents a state-machine that takes user input as a series of bytes representing ASCII characters and control codes. 48..57 is equivalent to the regular expression [0-9] (i.e. any digit), so only sequences beginning with a digit can be recognised. If 10 (line feed) is encountered, the program is done. 46 is the decimal point ('.'), 43 and 45 are positive and negative signs ('+', '-') and 69/101

391-424: The map. In this way, every map has, to some extent, been generalized to match the criteria of display. This includes small cartographic scale maps, which cannot convey every detail of the real world. As a result, cartographers must decide and then adjust the content within their maps, to create a suitable and useful map that conveys the geospatial information within their representation of the world. Generalization

414-469: The process of identifying the parts of a whole, as belonging to the whole. The parts, which might be unrelated when left on their own, may be brought together as a group, hence belonging to the whole by establishing a common relation between them. However, the parts cannot be generalized into a whole—until a common relation is established among all parts. This does not mean that the parts are unrelated, only that no common relation has been established yet for

437-679: The rest of the table is navigated. This column is called "stub column". Tables may contain three or multiple dimensions and can be classified by the number of dimensions. Multi-dimensional tables may have super-rows - rows that describe additional dimensions for the rows that are presented below that row and are usually grouped in a tree-like structure. This structure is typically visually presented with an appropriate number of white spaces in front of each stub's label. In literature tables often present numerical values, cumulative statistics, categorical values, and at times parallel descriptions in form of text. They can condense large amount of information to

460-679: The same information are presented side by side. On the left is the NFPA 704 standard " fire diamond " with example values indicated and on the right is a simple table displaying the same values, along with additional information. Both representations convey essentially the same information, but the tabular representation is arguably more comprehensible to someone who is not familiar with the NFPA 704 standard. The tabular representation may not, however, be ideal for every circumstance (for example because of space limitations, or safety reasons). There are several specific situations in which tables are routinely used as

483-528: The syntax. The code yielding the above example from the official website is: Table (information) A table is an arrangement of information or data , typically in rows and columns, or possibly in a more complex structure. Tables are widely used in communication , research , and data analysis . Tables appear in print media, handwritten notes, computer software, architectural ornamentation, traffic signs, and many other places. The precise conventions and terminology for describing tables vary depending on

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506-399: The term tree which stands for equally ranked items such as peach and oak , and the term ship which stands for equally ranked items such as cruiser and steamer . In contrast, a hyponym is one of the items included in the generic, such as peach and oak which are included in tree , and cruiser and steamer which are included in ship . A hypernym is superordinate to a hyponym, and

529-407: The use of tabular specification methodologies, examples of which include Software Cost Reduction and Statestep. Proponents of tabular techniques, among whom David Parnas is prominent, emphasize their understandability, as well as the quality and cost advantages of a format allowing systematic inspection, while corresponding shortcomings experienced with a graphical notation were cited in motivating

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