Re: [NTG-context] Proposal for math mappings

On Fri, 10 Dec 2010, Procházka Lukáš Ing. - Pontex s. r. o. wrote:

On Fri, 10 Dec 2010 05:49:26 +0100, Aditya Mahajan wrote:

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This is a proposal for a new way of selecting math mappings in MkIV. I want to get input from other math users whether this syntax would take care of all scenarios or not.

There are five different ranges in mathematics: - digits (0..9) - lower case Latin (abc..z) - upper case Latin (ABC..Z) - lower case Greek (αβγ..ζ) - upper case Greek (ΑΒΓ..Z)

Just to confirm -

- 0-9 are 48-57 in ASCII - a-z = 97-122 - A-Z = 65-90 - LC Greek = ?-? (given by \alpha to \omega range) - UC Greek = ?-? (given by \Alpha to \Omega range)

- Is that right?

Yes. In addition, Greek will work even if you key in 0x0391-0x03C9.

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A user may want to control what each range is mapped to. So, I suggest a setup command

\setupmathmappings [ digits={style,alternative}, lclatin={style,alternative}, uclatin={style,alternative}, lcgreek={style,alternative}, ucgreek={style,alternative}, ]

OK, it might be useful when one wants e.g. ALL Greek letters to be printed somehow, e.g. bold.

I don't think that the basic criterion for style in math is the (alphabet) range, it's rather the meaning of maths (variable/parameter/vector/tensor/operator (e.g. Nabla operator)). But OK -

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where the options for style are

normal, bold

while the options for alternative are

normal, italic, sans, sansitalic, blackboard, script

This command will the mappings for each range. **NOTE**: All combinations are not valid.

A companion command

\definemathmappings [whatever] [....]

can be used to define multiple mappings. These mappings can be used by

\setupmathmappings[whatever]

(An alternative is that these mappings are activated using \whatever ...)

For example, we can define a command to typeset vectors using

\definemathmappings [vectors] [ digits={bold,normal}, lclatin={bold,normal}, uclatin={bold,normal}, lcgreek={bold,normal}, ucgreek={bold,normal}]

\def\VEC{\groupedcommand{\setupmathmappings[vector]}{}}

Or rather the following (?): \def\VEC#1{\groupedcommand{\setupmathmappings[vector]}{#1}}

I haven't tested this, but I think that my definition should work (after changing vector -> vectors). The point of grouped command is that you can use \VEC{ABC} as well as {\VEC ABC} If you only need the first variant, you can simply define \def\VEC#1{{\setupmathmappings[vectors]#1}}

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If later, we want to represent vectors as sans serif, we can use

\definemathmappings [vectors] [ digits={normal,sans}, lclatin={normal,sans}, uclatin={normal,sans}, lcgreek={normal,sans}, ucgreek={normal,sans}]

This kind of switching would be great.

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This interface makes it easy to switch math fonts for disciplines that want different style for different alphabet ranges.

It is relatively easy to implement the above interface. All we need is some bookkeeping to set the right attributes. The default math mapping commands can be reimplmeneted using \definemappings. Before implementing this, I want to ask the opinion of other math users.

Would the above interface take care of different use cases, or is it missing something?

It looks good. Some examples would be needed, starting at simple ones and ending with "wildly" switching math formulas.

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Finally, I am not too happy with the syntax. There are only a few ConTeXt commands in which the keys take a pair of values. Another option is to allow all 12 valid options

normal, italic, sans, sansitalic, blackboard, script, bold, bolditlaic, boldsans, boldsansitalic, boldblackboard, boldscript

with the variants sansitalic-italicsans, boldsans-sansbold, etc. as synonmyms.

Which way of specifying the keys do you prefer?

Personally, no matter. Programming "clarity" should be kept at most - so it's up to you. When some samples are provided, someone will follow them.

I will provide a more detailed example. Aditya