There's little thunder, no off-piste mental excursions, no sense of a writer stropping his razor.
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But it was John's agonizing death at 26 — he contracted tetanus after slicing off a tiny piece of a finger while stropping a razor — that set Thoreau on the path that eventually led him to Walden Pond.
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In the song "Pretty Women" from "Sweeney," as the voluptuous tune and ethereal lyrics ("dancing" and "glancing" rhyme with "how they make a man sing") pulse toward what feels like erotic release, the vengeful barber is stropping the blade that will soon kiss his customer's neck.
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The method of stropping and the term "stropping" arose in the development of ALGOL in the 1960s, where it was used to represent typographical distinctions (boldface and underline) found in the publication language which could not directly be represented in the hardware language – a typewriter could have bold characters, but in encoding in punch cards there were no bold characters. The term "stropping" arose in ALGOL 60, from "apostrophe", as some implementations of ALGOL 60 used apostrophes around text to indicate boldface, such as `'if'` to represent the keyword if. Stropping is also important in ALGOL 68, where multiple methods of stropping, known as "stropping regimes", are used; the original matched apostrophes from ALGOL 60 was not widely used, with a leading period or uppercase being more common, as in `.IF` or `IF` and the term "stropping" was applied to all of these.
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Stropping is traditionally associated with straight razors used for shaving, as these are the thinnest blades in everyday use, and therefore require frequent stropping. Kitchen knives may be straightened on a honing steel if less sharpness is acceptable. In principle, any blade may be polished by stropping. Custom strops are made to hone irregularly-shaped tools, such as chisels or gouges, and nearly any piece of smooth leather or heavy fabric infused with abrasive compound may be used for stropping.
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In computer language design, stropping is a method of explicitly marking letter sequences as having a special property, such as being a keyword, or a certain type of variable or storage location, and thus inhabiting a different namespace from ordinary names ("identifiers"), in order to avoid clashes. Stropping is not used in most modern languages – instead, keywords are reserved words and cannot be used as identifiers. Stropping allows the same letter sequence to be used both as a keyword and as an identifier, and simplifies parsing in that case – for example allowing a variable named `if` without clashing with the keyword if. Stropping is primarily associated with ALGOL and related languages in the 1960s.
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While this is superficially similar to stropping, the semantics are different. As a reserved word, the string `__foo` represents the identifier `__foo` in the common identifier namespace. In stropping (by prefixing keywords by `__`), the string `__foo` represents the keyword `foo` in a separate keyword namespace. Thus using reserved words, the tokens for `__foo` and `foo` are (identifier, __foo) and (identifier, foo) – different values in the same category – while in stropping the tokens for `__foo` and `foo` are (keyword, foo) and (identifier, foo) – same values in different categories.
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A straight razor with a hanging strop A razor strop (or razor strap) is a flexible strip of leather, canvas, denim fabric, balsa wood, or other soft material, used to straighten and polish the blade of a straight razor, a knife, or a woodworking tool like a chisel. In many cases stropping re-aligns parts of the blade edge that have been bent out of alignment. In other cases, especially when abrasive polishing compound is used, stropping may remove a small amount of metal. Stropping can also burnish (i.e.
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Names containing double underscore or beginning with an underscore and a capital letter are reserved for implementation (compiler, standard library) and should not be used (e.g. `__reserved` or `_Reserved`). This is superficially similar to stropping, but the semantics differ: the underscores are part of the value of the identifier, rather than being quoting characters (as is stropping): the value of `__foo` is `__foo` (which is reserved), not `foo` (but in a different namespace).
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The railway line upon which various of the characters travel during the story includes the following stations: Stropping, Crampton Place, Packington, Gorsemont, De Conque, Raaxfall, St. Triste, St. Porte, Orange Locks, Orange Canal.
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Directives date to ALGOL 68, where they are known as pragmats (from "pragmatic"), and denoted pragmat or pr; in newer languages, notably C, this has been abbreviated to "pragma" (no 't'). A common use of pragmats in ALGOL 68 is in specifying a stropping regime, meaning "how keywords are indicated". Various such directives follow, specifying the POINT, UPPER, RES (reserved), or quote regimes. Note the use of stropping for the pragmat keyword itself (abbreviated pr), either in the POINT or quote regimes: .
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Stropping may bring a somewhat sharp blade to "like new" condition. A leather strop on a wooden handle, top. The leather is coated with green chromium oxide polishing compound. Bottom, one pattern of butcher's steel for knife edge maintenance.
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There are other, more minor examples. For example, Web IDL uses a leading underscore `_` to strop identifiers that otherwise collide with reserved words: the value of the identifier strips this leading underscore, making this stropping, rather than a naming convention.
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Care should also be taken when stropping so that the thin blade will not be overly stressed, since it cannot withstand abuse as well as lower grades. Flat ground razors are very stable and as such they can handle tough shaving jobs since they do not easily deform under pressure and they can take rough handling such as heavy stropping and honing. Although a wider blade is not as manoeuvreable as a narrower one, especially in tight spots, it is better to purchase a wider blade, since honing eventually reduces the width of the blade with use, a fact that can shorten the life of a straight razor with a narrow blade. On the other hand, the width of the blade is proportional to the blade distortion that can occur due to temperature fluctuations; this can lead to more frequent stropping and honing, because blade deformation due to thermal stress can lead to loss of cutting edge sharpness.
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These razors are similar in use and appearance to straight razors, but use disposable blades, either standard double edged cut in half or specially made single edge. These shavettes are used in the same way as straight razors but do not require stropping and honing.
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The cloth is used for blade alignment and sharpening. The leather is for finishing. During stropping, the strop hangs from the ring and is pulled from the rectangular loop giving it a proper tension The stropping process involves sliding the razor blade flat on the strop; upon reaching the end of the cloth or leather near the suspension ring, the blade is turned about its back (clockwise for a right-handed barber; counter-clockwise for a left-handed one) until the cutting edge touches the strop. It is then pulled toward the rectangular handle of the strop with back and cutting edge flat on the strop as before.
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The PostScript language and Microsoft Rich Text Format also use backslash escapes. The quoted-printable encoding uses the equals sign as an escape character. URL and URI use percent-encoding to quote characters with a special meaning, as for non-ASCII characters. Another similar (and partially overlapping) syntactic trick is stropping.
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The profile of the Spanish point has a small, rounded tip at the head, followed by a long concave arch, ending in a small rounded edge at the toe. This point should be used with care when shaving or stropping, as it tends to "bite" due to its pronounced edges.
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Actually a form of stropping, the use of many languages in Microsoft's .NET Common Language Infrastructure (CLI) requires a way to use variables in a different language that may be keywords in a calling language. This is sometimes done by prefixes. In C#, any variable names may be prefixed with "`@`".
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While modern languages generally use reserved words rather than stropping to distinguish keywords from identifiers – e.g., making `if` reserved – they also frequently reserve a syntactic class of identifiers as keywords, yielding representations which can be interpreted as a stropping regime, but instead have the semantics of reserved words. This is most notable in C, where identifiers that begin with an underscore are reserved, though the precise details of what identifiers are reserved at what scope are involved, and leading double underscores are reserved for any use; similarly in C++ any identifier that contains a double underscore is reserved for any use, while an identifier that begins with an underscore is reserved in the global space. Thus one can add a new keyword `foo` using the reserved word `__foo`.
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Thus in the strict language the following expression is legal, as the bold keyword if does not conflict with the ordinary identifier `if`: :if if eq 0 then 1 fi However, in ALGOL 68 there is also a stropping regime in which keywords are reserved words, an example of how these distinct concepts often coincide; this is followed in many modern languages.
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Stropping a knife is a finishing step. This is often done with a leather strap, either clean or impregnated with abrasive compounds (e.g. chromium(III) oxide or diamond), but can be done on paper, cardstock, cloth, or even bare skin in a pinch. It removes little or no metal material, but produces a very sharp edge by either straightening or very slightly reshaping the edge.
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A number of similar techniques exist, generally prefixing or suffixing an identifier to indicate different treatment, but the semantics are varied. Strictly speaking, stropping consists of different representations of the same name (value) in different namespaces, and occurs at the tokenization stage. For example, in ALGOL 60 with matched apostrophe stropping, `'if'` is tokenized as (Keyword, if), while `if` is tokenized as (Identifier, if) – same value in different token classes. Using uppercase for keywords remains in use as a convention for writing grammars for lexing and parsing – tokenizing the reserved word `if` as the token class IF, and then representing an if-then- else clause by the phrase `IF Expression THEN Statement ELSE Statement` where uppercase terms are keywords and capitalized terms are nonterminal symbols in a production rule (terminal symbols are denoted by lowercase terms, such as `identifier` or `integer`, for an integer literal).
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In ALGOL family languages, it is necessary to distinguish between identifiers and basic symbols of the language. In printed texts this was usually accomplished by printing basic symbols in boldface or underlined (begin or _begin_ for example). In source code programs, some stropping technique had to be used. In many ALGOL like languages, before ALGOL 68-R, this was accomplished by enclosing basic symbols in single quote characters ('begin' for example).
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Most modern computer languages do not use stropping, with two notable exceptions: The use of many languages in Microsoft's .NET Common Language Infrastructure (CLI) requires a way to use variables in a different language that may be keywords in a calling language. This is sometimes done by prefixes, such as `@` in C#, or enclosing the identifier in brackets, in Visual Basic.NET. A second major example is in many implementations of Structured Query Language.
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In some cases the same syntax can be used for distinct purposes, which can cause confusion. For example, in C#, the "`@`" prefix can be used either for stropping (to allow reserved words to be used as identifiers), or as a prefix to a literal (to indicate a raw string); in this case neither use is a sigil, as it affects the syntax of identifiers or the semantics of literals, not the semantics of identifiers.
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In grebes, this is done more vigorously with an open bill and is termed "stropping". In penguins, the head is also used in a motion referred to as "wiping". Some birds will also use their feet in an action termed as scratch-preening which is usually applied to the head. Some species (including nightjars, herons, frigatebirds, owls and pratincoles) have comb-like serrations on the claw (a pectinate claw) of the middle toe which may aid in scratch preening.
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Rouge is sold as a powder, paste, laced on polishing cloths, or solid bar (with a wax or grease binder). Other polishing compounds are also often called "rouge", even when they do not contain iron oxide. Jewelers remove the residual rouge on jewelry by use of ultrasonic cleaning. Products sold as "stropping compound" are often applied to a leather strop to assist in getting a razor edge on knives, straight razors, or any other edged tool.
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Edge of a Leatherman Crater pocket knife after sharpening and stropping. Although this edge is sharp enough to bite a thumbnail, cut paper smoothly, or shave arm hair, the hobby digital microscope plainly shows an approximately 0.01 mm wide edge, which reflects light back into the lens. A truly sharp edge is too thin to reflect significant light. By touch, a blade can be checked by running a thumb across the blade (perpendicular to the edge – not along, which will cut it).
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In a long shot of an Indian village way out West, all of the tepees have TV antennas, and some of the tepees are shops displaying Indian-made wares and merchandise. In the foreground is a millinery shop with a window full of feathered hats and coats, etc.; in the rear is a barber shop, complete with revolving barber pole. We discover Woody Woodpecker in the barber's chair reading a magazine, with Indian barber Buzz Buzzard stropping the blade of a tomahawk.
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In those languages reserved words can be used as column, table, or variable names by lexically delimiting them. The standard specifies enclosing reserved words in double quotes, but in practice the exact mechanism varies by implementation; MySQL, for example, allows reserved words to be used in other contexts by enclosing them in backticks, and Microsoft SQL Server uses square brackets. Stropping can also be used in the Nim programming language. In Nim, a reserved word can be used as an identifier by enclosing it in backticks.
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In 68-R, basic symbols could be distinguished by writing them in upper case, lower case being used for identifiers. As ALGOL 68-R was implemented on a machine with 6-bit bytes (and hence a 64 character set) this was quite complex and, at least initially, programs had to be composed on paper punched tape using a Friden Flexowriter. Partly based on the experience of ALGOL 68-R, the revised report on ALGOL 68 specified hardware representations for the language, including UPPER stropping.
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Blade cross-sections for typical grinds # Hollow grind — a knife blade ground to create a characteristic concave, beveled cutting edge. This is characteristic of straight razors, used for shaving, and yields a very sharp but weak edge, which requires stropping for maintenance. # Flat grind — The blade tapers all the way from the spine to the edge from both sides. A lot of metal is removed from the blade, so it is thus more difficult to grind, which is one factor that limits its commercial use.
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NET library may contain a class definition such as: ' Class Definition of This in Visual Basic.NET: Public Class this ' This class does something... End Class If this is compiled and distributed as part of a toolbox, a C# programmer, wishing to define a variable of type “`this`” would encounter a problem: `'this'` is a reserved word in C#. Thus, the following will not compile in C#: // Using This Class in C#: this x = new this(); // Won't compile! A similar issue arises when accessing members, overriding virtual methods, and identifying namespaces. This is resolved by stropping.
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Due to its premium pricing strategy, the Gillette Safety Razor Company's razor and blade unit sales grew at a modest pace from 1908 to 1916. Disposable razor blades still weren't a true mass-market product, and barbershops and self-shaving with a straight razor were still popular methods of grooming. Among the general U.S. population, a two-day stubble was not uncommon. This changed once the United States declared war on the Central Powers in 1917; military regulations required every soldier to provide their own shaving kit, and Gillette's compact kit with disposable blades outsold competitors whose razors required stropping.
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However, one stropping regime was to not strop the keywords, and instead have them simply be reserved words. Some languages, such as PostScript, are extremely liberal in this approach, allowing core keywords to be redefined for specific purposes. In Common Lisp, the term "keyword" (or "keyword symbol") is used for a special sort of symbol, or identifier. Unlike other symbols, which usually stand for variables or functions, keywords are self-quoting and self-evaluatingPeter Norvig: Paradigms of Artificial Intelligence Programming: Case Studies in Common Lisp, Morgan Kaufmann, 1991, , Web:98 and are interned in the `KEYWORD` package.
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Further code production is of course abandoned. This problem can be reduced through the employment of reserved words, so that for example "if", "then", and "else" always are parts of an if-statement and cannot be names of variables, but a surprisingly large number of useful words may thereby become unavailable. Another approach is "stropping", whereby reserved words are marked off, say by placing them between special characters such as full stops, or apostrophes as in some versions of Algol. This means that `'if'` and `if` are different tokens, the latter being an ordinary name, but supplying all those apostrophes soon becomes irksome.
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This is usually done for forward compatibility, so a reserved word may become a keyword in a future version without breaking existing programs. Conversely, keywords need not be reserved words, with their role understood from context, or they may be distinguished in another manner, such as by stropping. For example, the phrase `if = 1` is unambiguous in most grammars, since a control statement of an if clause cannot start with an `=`, and thus is allowed in some languages, such as FORTRAN. Alternatively, in ALGOL 68, keywords must be stropped – marked in some way to distinguished – in the strict language by listing in bold, and thus are not reserved words.
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Safety razors were popularized in the 1900s by King Camp Gillette's invention, the double-edge safety razor. While other safety razors of the time used blades that required stropping before use and after a time had to be honed by a cutler, Gillette's razor used a disposable blade with two sharpened edges. Gillette's invention became the predominant style of razor during and after the First World War, when the U.S. Army began issuing Gillette shaving kits to its servicemen. Since their introduction in the 1970s, cartridge razors and disposable razors – where the blades are embedded in plastic – have become the predominant types of safety razors.
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While sigils are applied to names (identifiers), similar prefixes and suffixes can be applied to literals, notably integer literals and string literals, specifying either how the literal should be evaluated, or what data type it is. For example, `0x10ULL` evaluates to the value 16 as an unsigned long long integer in C++: the `0x` prefix indicates hexadecimal, while the suffix `ULL` indicates unsigned long long. Similarly, prefixes are often used to indicate a raw string, such as `r"C:\Windows"` in Python, which represents the string with value `C:\Windows`; as an escaped string this would be written as `"C:\\Windows"`. As this affects the semantics (value) of a literal, rather than the syntax or semantics of an identifier (name), this is neither stropping (identifier syntax) nor a sigil (identifier semantics), but it is syntactically similar.
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