Glyph: Difference between revisions

Jump to navigation Jump to search
485 bytes added ,  15:55, 7 May 2021
no edit summary
m (Text replacement - "wikipedia:Overstrike" to "overstrike")
Tags: Mobile edit Mobile web edit
No edit summary
Line 3: Line 3:
Most of APL's glyphs cannot be represented in [[wikipedia:ASCII|ASCII]], now considered a "standard" or "basic" character set, but all of them are included in [[Unicode]], as one goal of Unicode was to unify existing character sets. In fact, [[Ken Iverson]] first began using [[Iverson notation|his notation]] before work on ASCII began, and [[APL\360]] was implemented before the modern ASCII standard was published in 1967. Prior to the widespread adoption of Unicode, many [[wikipedia:Digital encoding of APL symbols|special purpose code pages]] were used to represent APL symbols. APLs developed more recently, such as [[NARS2000]] and [[GNU APL]], use Unicode characters to represent glyphs, sometimes supporting several different options for a given glyph. Unicode also offers the possibility of introducing glyphs that could not have been produced on older APL systems: for example, both [[NARS2000]] and [[dzaima/APL]] use <source lang=apl inline>√</source> for the [[Square Root]] and [[Root]] functions.
Most of APL's glyphs cannot be represented in [[wikipedia:ASCII|ASCII]], now considered a "standard" or "basic" character set, but all of them are included in [[Unicode]], as one goal of Unicode was to unify existing character sets. In fact, [[Ken Iverson]] first began using [[Iverson notation|his notation]] before work on ASCII began, and [[APL\360]] was implemented before the modern ASCII standard was published in 1967. Prior to the widespread adoption of Unicode, many [[wikipedia:Digital encoding of APL symbols|special purpose code pages]] were used to represent APL symbols. APLs developed more recently, such as [[NARS2000]] and [[GNU APL]], use Unicode characters to represent glyphs, sometimes supporting several different options for a given glyph. Unicode also offers the possibility of introducing glyphs that could not have been produced on older APL systems: for example, both [[NARS2000]] and [[dzaima/APL]] use <source lang=apl inline>√</source> for the [[Square Root]] and [[Root]] functions.


Because of difficulties associated with non-ASCII characters (while display problems have been almost eliminated by Unicode, entering the characters may still be a barrier), several array-family languages such as [[J]], [[K]], and [[ELI]] have chosen to encode the language using only ASCII, either by reducing and compacting functionality to use one character per glyph or by using multiple characters in some cases (in J, these are called "bigraphs" and "trigraphs"). Historically there have also been various encodings of APL in smaller character sets, typically as an alternate way of writing code for an APL with traditional glyphs.
While [[Iverson notation]] was originally handwritten, the choice of glyphs to include in the first APL implementations was influenced by technical constraints of the typewriters used at the time. Notably, many glyphs were produced by overlaying two simpler glyphs, a technique known as [[overstrike|overstriking]].
 
== Alternatives ==
 
Display problems have been mostly eliminated by the broad uptake of Unicode. However some difficulties with [[typing glyphs]] remain. Several APL-family languages such as [[J]], [[K]], and [[ELI]] have chosen to stick with ASCII, either by reducing and compacting functionality to use one character per glyph or by using multiple characters. Historically there have also been various encodings of APL in smaller character sets, typically as an alternate way of writing code for an APL with traditional glyphs.


While [[Iverson notation]] was originally handwritten, the choice of glyphs to include in the first APL implementations was influenced by technical constraints of the typewriters used at the time. Notably, many glyphs were produced by overlaying two simpler glyphs, a technique known as [[overstrike|overstriking]].
== Bi-glyphs ==
J and K use both ASCII symbols on their own, and followed by one or more periods and/or colons. J terminology calls these ''bigraphs'' and ''trigraphs''. For example, J uses <source lang=j inline>^</source> for [[Power]], <source lang=j inline>^.</source> for [[Logarithm]], and <source lang=j inline>^:</source> for the [[Power operator]], while K uses <source lang=k inline>':</source> for the equivalent of [[Windowed_Reduce#Notable_uses|pair-wise reduction]] (<source lang=apl inline>¯2f/</source>) and <source lang=k inline>0:</source> for line-by-line file read/write.


{{APL features}}
{{APL features}}
{{APL glyphs}}
{{APL glyphs}}
[[Category:Glyphs| ]]
[[Category:Glyphs| ]]

Navigation menu