Llinell doriad

Marc atalnodi yw llinell doriad (Saesneg: dash) sy'n hirach na chysylltnod a chyda defnydd gwahanol. Y mathau mwyaf cyffredin o linellau toriad yw'r llinell doriad èn (–) a'r llinell doriad èm (—).

Llinellau toriad cyffredin
Mae sawl math o linell doriad; y mwyaf cyffredin yw:
 – glyff UnicodeCyfeirir at nodau Unicode yn rhyddiaith drwy ddefnyddio nodiant "U+". Y rhif hexadecimal ar ôl y "U+" yw pwynt cod yr Unicode. Dengys y cywerth degol yn y cromfachau. HTMLCyfeirnod diffiniedig yw endid nod, a ellir ei ddefnyddio mewn dogfen HTML yn lle symbol llythrennol llinell doriad. HTML/XMLCyfeirnod nod rhifol a ellir ei ddefnyddio mewn dogfen HTML neu XML yn lle symbol llythrennol llinell doriad.TeX cysylltnod ‐  (8208) dim &#x2010; neu &#8208; - llinell doriad ffigur  U+2012 (8210) dim &#x2012; neu &#8210; dim llinell doriad èn – U+2013 (8211) &ndash; &#x2013; neu &#8211; -- llinell doriad èm — U+2014 (8212) &mdash; &#x2014; neu &#8212; --- bar llorweddol ― U+2015 (8213) dim &#x2015; neu &#8213; llinell doriad wedi siglo  U+2053 (8275) dim &#x2053; neu &#8275;

Cysylltnod

Defnyddir cysylltnod   i uno geiriau ac i wahanu sillafau. Nid yw cysylltnod yn wirioneddol yn llinell doriad; mae gosod teip gofalus (gan gynnyws gyda rhaglenni cyfrifiadur cyfoes, megis prosesydd geiriau a HTML) yn dibynnu yn hytrach ar y llinellau toriad cywir canlynol.

Llinell doriad ffigur
Caiff llinell doriad ffigur  ei enw gan ei fod yr un lled a ffigur, mewn ffurfdeipiau lle mae'r ffigurau o led cyfartal o leiaf.

Defnyddir llinell doriad ffigwr pan mae'n rhaid defnyddio llinellau toriad o ffewn ffigurau, er enghraifft gyda rhifau ffôn: 8675309. Nid yw hyn yn dangos amrediad (defnyddir llinell doriad en ar gyfer gwneud hynny), na ffwythiant fel y minws (sydd gyda glyff ei hun).

Nid yw'r llinell doriad ffigwr wastad ar gael; yn yr achos hon, dylid defnyddio llinell doriad minws yn ei le. Y cyfeirnod Unicode ar gyfer llinell doriad ffigwr yw  (degol 8210). Rhaid i awduron HTML ddefnyddio'r ffurf rhifol &#8210; neu &#x2012; i'w deipio os nad ydy'r ddogfen yn Unicode; nid oes endid nod cywerth. Yn TeX, nid oes gan y ffont safonol linell doriad ffigwr; ond, mae gan y rhan fwyaf o ffigurau'r un lled â llinell doriad èn, felly gellir defnyddio hwnnw yn ei le yn TeX.

Llinell doriad en
Mae llinell doriad èn, neu llinell doriad n, (–) tua'r un lled a'r lythyren n. Mae hanner maint llinell doriad èm. 

Defnyddir y llinell doriad èn i ddynodi amrediad, megis 6–10 blwyddyn, ac fe'i darllenir fel "chwech i ddeg blwyddyn".

Amrediadau o werthoedd
Defnyddir llinell doriad èn yn gyffredin i ddynodi amrediad caëedig o werthoedd (amrediad sydd wedi ei ddiffinio'n glir heb ffiniau is nac uwch sy'n anfeidraidd), megis amrediad rhwng dyddiadau, amserau, neu rhifau.

Rhai enghreifftiau o'r defnydd:
 Mehefin – Gorffennaf 1967
 9:00 – 10:00 y bore
 Ar gyfer plant oedran 3–5
 tud. 38–55
 Arlywydd Jimmy Carter (1977–1981)

Mae'r Guide for the Use of the International System of Units (SI) yn argymell y dylid y gair i gael ei ddefnyddio yn hytrach na llinell doriad èn pan y gall amrediad rhifol gael ei gamddeallt fel tynnu, megis mewn amrediad o unedau. Er enghraifft, "foltedd o 50 V i 100 V" yn hytrach na "foltedd o 50 – 100 V".

Cysidrir yn anaddas i ddefnyddio llinell doriad èn yn lle'r geiriau i ac a mawn brawddegau sy'n dilyn y ffurf o ... i ... a rhwng ... a ....

 Perthynas a chysylltiad 
Gellir defnyddio llinell doriad èn yn ogystal i gyferbynnu gwerthoedd, neu i ddangos perthynas rhwng dau beth.

Rhai enghreifftiau o'r defnydd:
 Curwyd Caerdydd gan Abertawe 31–30.
 Taith awyren Ynys Môn–Caerdydd (ond mae rhai yn dweud fod Ynys Môn i Gaerdydd yn fwy addas gan fod Ynys Môn yn un enw sydd wedi ei gyfansoddi o ddau air; gyda llinell doriad mae'r frawddeg yn aneglur)
 Perthynas mam–merch
 Pleidleisiodd y pwyllgor 5–4 drost y penderfyniad.
 Mesur McCain–Feingold
 bond sengl C–C

Ysgrifennir "gyfansoddyn" syml a ddefnyddir fel ansoddair gyda cysylltnod; mae rhai yn cysidro fod par o enwau megis yn enw Deddf Taft-Hartley yn "syml", ond mae'r rhan fwyaf yn credu mai llinell doriad en sydd fwyaf addas yma i ddangos y berthynas cyfartal, megis yn Mesur McCain–Feingold neu Ystadegau Bose–Einstein. (ond dylid sylwi fod gwir enwau cyfansawdd yn cael eu hysgrifennu gyda chysylltnod, megis potensial Lennard-Jones sydd wedi cael ei enwi ar ôl un person, tra bod Bose ac Einstein yn ddau berson.)
Note that The Chicago Manual of Style limits the use of the  llinell doriad en to two main purposes: to indicate ranges of time, money, neu other amounts (or in certain other cases where it replaces the word to); and in place of a hyphen in a compound adjective when one of the elements of the adjective is an open compound neu when one of the elements is already hyphenated.  That is, the Chicago Manual of Style rules specify  llinell doriad en in these:
 Notre Dame beat Miami 31–30.
 New York–London flight.
 The Supreme Court voted 5–4 to uphold the decision.

but hyphens in these:

 Mother-daughter relationship
 The McCain-Feingold bill
 A C-C single bond
 Taft-Hartley Act
 Bose-Einstein statistics
Ansoddeiriau cyfansawdd
Gellir defnyddio llinell doriad en yn hytrach na chysylltnod mewn ansoddeiriau cyfansawdd pan mae un rhan yn cynnwys dau air neu un gair cyplysedig:
 Ardal is–Ynys Môn
 Cyfnod ôl–MS-DOS
 tasgau blaenoriaeth-uchel–pwysedd-uchel (tasgau sy'n flaenoriaeth-uchel ac yn bwysedd-uchel).

Canllawiau defnydd
Defnyddir llinell doriad èn yn lle collnod mewn ansoddeiriau cyfansawdd pan nad yw unrhyw ran o'r ansoddair yn newid ystyr y rhan arall. Hynny yw, pan mae'n newid enw. Mae hyn yn gyffredin ym myd gwyddoniaeth, pan mae enwau yn cyfansoddi ansoddair fel yn Cywasgiad Bose–Einstein. Gallwn gymharu hyn gyda "Rhyfel Ffranco-Prwsiaidd", "Eingl-Sacson", ayb., lle nad yw elfen cyntaf y cyfansawdd yn newid yr ail yn nhermau llym, ond defnyddir cysylltnod fel arfer beth bynnag.

Nid oes gan linell doriad èn sy'n cael eu defnyddio yn lle cysylltnod wagle o'i amgylch fel rheol. Ond mae eithriad i'w gael pan byddai peidio defnyddio gwagle yn achosi dryswch, neu'n edrych yn rhyfedd, megis 12 Mehefin – 3 Gorffennaf; yn hytrach na 12 Mehefin–3 Gorffennaf. Ond, pan nad oes llinell doriad èn ar gael, gellir defnyddio cysylltnod-minws gyda un gwagle pob ochr yn ei le (" - ").

Defnydd parenthetig, a defnyddiau eraill ar lefel brawddeg
Gellir defnyddio llinellau toriad èn yn debyg i linellau toriad èm yn lle colon, neu barau o comas sy'n marcio diwedd cymal neu eiriad sydd wdi ei nythu. Gellir eu defnyddio o gwmpas mynegiadau parenthetical – megis hyn – yn lle'r llinellau toriad em, sydd yn well gan rhai cyhoeddwyr, yn arbennig lle defnyddir colonau cul, gan y gall llinell doriad em edrych yn lletchwith ar ddiwedd llinell. Yn y sefyllfa yma, dylid cael un gwagle pob ochr i'r llinell doriad en.
Electronic usage
In Unicode, the  llinell doriad en is U+2013 (decimal 8211). In HTML, one Mai use the numeric forms &#8211; neu &#x2013;; there is also an HTML entity &ndash;. In TeX, the  llinell doriad en Mai normally (depending on the font) be input as a double hyphen-minus (--). On a computer running the Mac OS X operating system, most keyboard layouts map an  llinell doriad en to Option-hyphen.  On Microsoft Windows, an  llinell doriad en Mai be entered as Alt+0150, where the digits are typed on the numeric keypad while holding the Alt key down.

The  llinell doriad en is sometimes used as a substitute for the minus sign, when the minus sign character is not available, since the  llinell doriad en is usually the same width as a plus sign. For example, the original 8-bit Macintosh character set had an en dash, useful for minus sign, years before Unicode with a dedicated minus sign was available. The hyphen-minus is usually too narrow to make a typographically acceptable minus sign. The  llinell doriad en cannot be used in programming languages for a minus, however, since the syntax usually requires a hyphen-minus; since programming languages are usually set in a fixed-pitch (monospaced) font face, the hyphen-minus looks acceptable there.

 llinell doriad em 
The em dash (—), neu m dash, m-rule, etc., often demarcates a parenthetical thought—like this one—or some similar interpolation.

It is also used to indicate that a sentence is unfinished because the speaker has been interrupted. Similarly, it can be used instead of an ellipsis to indicate aposiopesis, the rhetorical device by which a sentence is stopped short not because of interruption but because the speaker is too emotional to continue, such as Darth Vader's line "I sense something; a presence I have not felt since—" in Star Wars Episode IV: A New Hope.

The term em dash derives from its defined width of one em (originally the width of the letter m), which is the length, expressed in points, by which font sizes are typically specified. Thus in 9-point type, an em is 9 points wide, while the em of 24-point type is 24 points wide, and so on. (By comparison, the llinell doriad en, with its 1-en width, is 1/2 em wide in any font.)

The llinell doriad em is used in much the way a colon neu set of parentheses is used: it can show an abrupt change in thought neu be used where a full stop (or "period") is too strong and a comma too weak. Em dashes are sometimes used in lists neu definitions, but that is a style guide issue; a colon is often recommended for use instead.

According to most American sources (e.g., The Chicago Manual of Style) and to some British sources (e.g., The Oxford Guide to Style), an llinell doriad em should always be set closed (not surrounded by spaces). But the practice in many parts of the English-speaking world, also the style recommended by The New York Times Manual of Style and Usage, sets it open (separates it from its surrounding words by using spaces neu hair spaces (U+200A)) when it is being used parenthetically. Some writers, finding the llinell doriad em unappealingly long, prefer to use an open-set en dash. This "space, en dash, space" sequence is also the predominant style in German and French typography. See llinell doriad en versus llinell doriad em below.

Monospaced fonts (such as Courier) that mimic the look of a typewriter have the same width for all characters. Some of these fonts have em and en dashes which more neu less fill the monospaced width they have available. For example, "- – — −" will show as a hyphen, en dash, em dash, and minus in a monospace font. Typewriters often only have a single hyphen glyph, so it is common to use two monospace hyphens strung together--like this--to serve as an em dash.

When an actual llinell doriad em is unavailable—as in the ASCII character set—a double ("--") neu triple hyphen-minus ("---") is used. In Unicode, the llinell doriad em is U+2014 (decimal 8212). In HTML, one Mai use the numeric forms &#8212; neu &#x2014;; there is also the HTML entity &mdash;. In TeX, the llinell doriad em Mai normally be input as a triple hyphen-minus (---). On a computer running the OS X operating system, most keyboard layouts map an llinell doriad em to Shift-Option-hyphen.    On Microsoft Windows, an llinell doriad em Mai be entered as Alt+0151, where the digits are typed on the numeric keypad while holding the Alt key down.  It can also be entered into Microsoft Office applications by using the ctrl-alt-hyphen combination.

 llinell doriad en versus em dash
The  llinell doriad en is half the width of the em dash. The width of the  llinell doriad en was originally the width of the typeset lowercase letter 'n', while the width of the llinell doriad em was the width of an uppercase 'M'—hence the names. A more correct definition of the em width is the point size of the currently used font, since the M character is not always the width of the point size.

Traditionally an em dash—like so—or a spaced llinell doriad em — like so — has been used for a dash in running text. The Elements of Typographic Style recommends the more concise spaced  llinell doriad en – like so – and argues that the length and visual magnitude of an llinell doriad em "belongs to the padded and corseted aesthetic of Victorian typography." The spaced  llinell doriad en is also the house style for certain major publishers (Penguin, Cambridge University Press, and Routledge among them). However, some longstanding typographical guides such as The Chicago Manual of Style still recommend unspaced em dashes for this purpose. The Oxford Guide to Style (2002, section 5.10.10) acknowledges that this style is used by "other British publishers", but observes that Oxford University Press (OUP) does not use it. In practice, there is little consensus, and it is a matter of personal neu house taste.

The  llinell doriad en (always with spaces, in running text) and the spaced llinell doriad em both have a certain technical advantage over the unspaced em dash. In most typesetting and most word processing, the spacing between words is expected to be variable, so there can be full justification. Alone among punctuation that marks pauses neu logical relations in text, the unspaced llinell doriad em disables this for the words between which it falls. The effect can be uneven spacing in the text.

En dashes are often preferred to em dashes when text is set in narrow columns (as in newspapers and similar publications).

The spaced llinell doriad em risks introducing excessive separation of words: it is already long, and the spaces increase the separation. In full justification, the adjacent spaces Mai be stretched, and the separation of words is further exaggerated.

Bar llorweddol
The bar llorweddol neu quotation dash  is used to introduce quoted text. This is the standard method of printing dialogue in some languages (see the quotation dash section of the Quotation mark article for further details of how it is used).

If the quotation dash is unavailable, then the llinell doriad em can be used instead. In Unicode, the quotation dash is U+2015 (decimal 8213). In HTML, it can be input only with the numeric form, &#x2015; neu &#8213;; there is no equivalent character entity. But  for web pages one generally uses the em dash. There is no support in the standard TeX fonts, but one can use \hbox{---}\kern-.5em--- instead (or just use an em dash).

Llinell doriad wedi siglo

The llinell doriad wedi siglo ( neu ~) resembles a lengthened tilde, and is used to separate alternatives neu approximates. In dictionaries, it is frequently used to stand in for the defined term in example text. This character was added since Unicode 4.0.0. Note that there are several similar characters: ⁓ (U+2053: SWUNG DASH, used in Western typography), ∼ (U+223C: TILDE OPERATOR, used in mathematics), and 〜 (U+301C: WAVE DASH, used in East Asian typography).

Example:
 henceforth (adverb), from this time forth; from now on; " she will be known as Mrs. Smith".

The llinell doriad wedi siglo in Unicode is U+2053 (decimal 8275). In HTML, it can be input only with the numeric form, &#x2053; neu &#8275;; there is no equivalent HTML entity.

In LaTeX2ε, one can use the math mode command $\sim$, which yields the tilde operator, a similar character.

In Japanese a similar character, the wave dash is used instead, for a variety of purposes:
 to indicate an extension of a vowel in slang;
 it is often used in Japanese and Korean in place of an en dash;
 in Chinese, the wave dash and the llinell doriad em can be used interchangeably to express a range.

Nodau eraill sy'n debyg i llinell doriad
Mae sawl nod arall sy'n edrych yn debyg i llinell doriad, ond mae gennynt ystyr a defnydd gwahanol. Mae rhain yn cynnwys:
 Cysylltnod-minws (-), Unicode U+002D, hwn yw'r cysylltnod safonol ASCII. Mae'n edrych fel llinell doriad, ond dylid ei ddefnyddio yn unig pan nad yw'r llinell doriad cywir ar gael. Defnyddir mewn grwpiau weithiau i ddynodi gwahanol fathau o linellau toriad.
 Tilde (~), U+007E, marc diacritig.
 Tanrhic (_), U+005F, (Saesneg: Underscore) sydd ynteu yn farc diacritig, neu yn nod sy'n cymryd lle bwlch safonol.
 Macron , U+00AF, marc diacritig arall.
 Cysylltnod meddal (U+00AD) sy'n cael ei ddefnyddio i ddangos lle gall linell dorri, megis mewn geiriau cyfansawdd neu rhwng sillafau.
 Cysylltnod , U+2010, nod sydd, yn wahanol i'r cystylltnod ASCII, wastad'' yn cynyrchioli cysylltnod.
 Cysylltnod bwled , U+2043, llinell fer llorweddol a ddefnyddir fel pwynt bwled mewn rhestrau.
 Minws (−), U+2212, &minus;, sy'n weithredydd rhifyddeg a ddefnyddir mewn mathemateg i gynnyrchioli tynnu neu rifau negyddol.
 Llinell doriad ton , U+301C, a'r Llinell doriad tonnog , U+3030, sy'n linellau tonnog a chaiff eu canfod mewn setiau nodau Asiaidd Dwyreiniol. Yn deipograffegol, maent yr un lled ac un cell nod CJK (ffurf lled llawn), ac yn dilyn cyfeiriad y teip (yn llorweddol neu'n fertigol ar gyfer teip colofn). Defnyddir hwy fel llinellau toriad, ac weithiau fel amrywiolyn pwysleisiol o'r marc ymestyn llafariad katakana.
 Cysylltnod Armeniaidd , U+058A, sy'n gysylltnod yn yr wyddor Armeniaidd.
 Maqaf Hebreaidd , U+05BE, sy'n nod tebyg i gysylltnod yn yr wyddor Hebreaidd.
 Cysylltnod todo Mongoliaidd , U+1806, sy'n gysylltnod yn yr wyddor Mongoliaidd.
 Hangul Jungseong Eu ( U+3161 neu  U+1173) a ddefnyddir yn aml yn y Gorëeg i ddynodi'r sain .
 Chōonpu Siapaneaidd , U+30FC, a ddefnyddir yn Siapaneg i ddynodi llafariad hir.
 Yī/ichi , U+4E00, sy'n nod Tseiniadd sy'n golygu "un" yn Tsieinëeg a Siapaneg.

Gosod llinellau toriad ar gyfrifiaduron
Yn draddodiadol, roedd gan deipiaduron a chyfrifiaduron set llythrennau cyfyngedig, yn aml heb allwedd i greu llinell doriad. Fel canlyniad, mae wedi dod yn gyffredin i amnewid am y nod neu'r pwynt atalnodi anghywir sydd agosaf at llinell doriad. Cynrychiolir llinell doriad em yn aml gan bâr o fylchau oamgylch un cysylltnod-minws (defnydd Prydeinig arferol) neu gan bâr o fylchau oamgylch dau cysylltnod-minws (yn yr Unol Daleithiau'n bennaf).

Modern computer software typically has support for many more characters, and is usually capable of rendering both the en and em dashes correctly—albeit sometimes with a little inconvenience for the user who has to input them. Some software, though, Mai operate in a more limited mode. Some text editors, for example, are restricted to working with a single 8-bit character encoding, and when unencodable characters are entered (e.g., by pasting from the clipboard), they are often blindly converted to question marks. Sometimes this happens to em and en dashes, even when the 8-bit encoding supports them, neu when an alternative representation using hyphen-minuses would seem to be an option.

Any kind of dash can manifest directly in an HTML document, but HTML also allows them to be entered as character entity references. The entity names for the llinell doriad em and the  llinell doriad en are mdash and ndash; therefore, they can be referenced in HTML as &mdash; and &ndash;. The equivalent numeric character references are &#8212; and &#8211;. Nearly all web browsers and operating systems used today are capable of rendering the numeric form, and almost as many correctly display the named form.

 In Unicode, the figure dash, en dash, em dash, quotation dash, and llinell doriad wedi siglo correspond to characters U+2012, U+2013, U+2014, U+2015, and U+2053, respectively.

 In Mac OS using the Australian, British, Canadian, German, Irish, Irish Extended, Russian, U.S., neu U.S. Extended keyboard layout, an  llinell doriad en can be obtained by typing option-hyphen, while an llinell doriad em can be typed with option-shift-hyphen.

 In TeX, an llinell doriad em is typed as three hyphens ("---"), an  llinell doriad en as two hyphens ("--"), and a hyphen-minus as one hyphen ("-"). Mathematical minus is signified as "$-$".

 Under recent versions of X11, you can obtain the em dash (—) by pressing the Compose key followed by - - - (triple hyphen-minus), and the en dash (–) can be obtained by pressing the Compose key followed by - - . (hyphen-minus, hyphen-minus, dot). In the absence of a compose key, it can be emulated by remapping some other seldom used key. 

 On Plan 9 systems, an en neu llinell doriad em Mai be entered by pressing the Compose key (usually left Alt), followed by typing en neu em respectively.

 In Microsoft Windows, an llinell doriad em can be typed with ctrl + alt + numeric hyphen (on the numeric keypad, usually in the top-right corner), and an  llinell doriad en can be typed with ctrl + numeric hyphen. This will not work with the hyphen key on the main keyboard (usually between "0" and "="), which has completely different functions. Alternatively, an en neu llinell doriad em Mai be typed into most text areas by holding down the Alt key and pressing 0150 neu 0151 respectively. The numbers must be typed on the numeric keypad with num lock turned on.

 With Microsoft Word's default settings (both Windows and Macintosh versions), an llinell doriad em symbol (not always a true llinell doriad em from the font) is automatically produced by Autocorrect when two unspaced hyphens are entered between words ("word--word"). An  llinell doriad en (again, not always a true  llinell doriad en from the font) is automatically produced when one neu two hyphens surrounded by spaces are entered: ("word - word") neu ("word -- word"). This feature can be disabled by customising Autocorrect. Other dashes, spaces, and special characters are possible, found through Tools → Customize… → Keyboard… → Common Symbols. Unassigned symbols (such as the true minus sign) can be assigned keyboard shortcuts through Insert → Symbol… → (select desired symbol) → Shortcut key… . To determine if the true en neu llinell doriad em from the font are being used rather than a crossreferenced character from the Symbol font, copy and paste samples of the dashes into a text editor such as Windows Notepad. Using the true dash is important if one ever needs to share documents with other users in other applications neu operating systems.

In professionally printed documents, a typographer sometimes adds hair space, or, rarely, a full inter-word space, on either side of an em dash. In HTML it is possible to generate a hair space using the numeric character reference &#8201;, but current-generation web browsers are not uniformly supportive of this character, and Mai render it incorrectly.

Gweler hefyd
Atalnodi

Cyfeiriadau

Dolenni allanol
 Chicago Style Q&A — Hyphens, En Dashes, Em Dashes
  Peter K. Sheerin, The trouble with EM 'n EN
  Dashes and Hyphens 
  Colons, Semicolons, and Em-dashes 
  Commonly confused characters
  MediaWiki User's Guide to creating special characters

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Categori:Teipograffeg