Style markers in strings

Question

I'm dealing with strings in Mathematica and I would love to handle their stylling in the most cenvenient way.

Without loss of generality, let's assume I want to make some parts of string Bold.

Example of desired output:

to be or not to be

I know I can achieve that by for example:

StringForm["to `` or `` to be", ##] & @@ (Style[#, Bold]& /@ {"be", "not"}) 

but I want single function bold and some kind of markers (here #):

bold @ "to #be# or #not# to be"

to be or not to be

---

It is my approach:

bold = Module[{x}, 
              With[{patt = "#" ~~ x : Except["#"] .. ~~ "#"},
       StringForm @@ ({
                      StringReplace[#, patt :> "``"],
                      Sequence @@ StringCases[#, patt :> Style[x, Bold]]
                      })]
             ] &

and I have couple of questions about it:

• do you feel that # is not the best choice too? :)
• is this: {patt = "#"~~...} a proper way of storing patterns?
• maybe some other ideas?

I like this way but I'm not sure if it is bulletproof. It is quite handy because StringCases etc do not look for overlaps by default.

Notice that mixed-style-string-form tends to produce some kind of error If you want to edit that cell. This is also what I to want to ask about:

INTERNAL SELF-TEST ERROR: MathEditCells2|c|1384
Click here to find out if this problem is known, and to help improve
Mathematica by reporting it to Wolfram Research

Answer 1

You can use # or any other marker for your personal use, but for general purposes, I prefer sticking to the Markdown scheme that we're all familiar with, and is used in several other places. With the styleMarkdown function defined later in this answer, we can do something like this:

styleMarkdown["The **quick** brown fox *jumps* over the ***lazy*** dog."]

Here's the code for the above function:

ClearAll@styleMarkdown
styleMarkdown[str_String] := Module[{style, applyRules},
    style[s_String, {weight_ : Plain, slant_ : Plain}] := StringJoin[
        "\!\(\*StyleBox[\"", s, "\", FontWeight -> ", ToString@weight,
        ", FontSlant -> " , ToString@slant, "]\)"];

    applyRules[s_String, rules_] := 
        StringReplace[s, # ~~ Shortest@x__ ~~ # :> style[x, #2] & @@@ rules];

    applyRules[str, {"***" -> {Bold, Italic}, "**" -> {Bold}, "*" -> {Plain, Italic}}]
]

The function only handles bold, italic and bolditalic, but you can extend it to other styles, if you want. The limitations in markdown also apply here. For example, with ****foo****, is it to be interpreted as (markers in [] and styled text in <>) *[***<foo>***]* or [***<*foo>***]* or *[***<foo*>***], and so on.