Inconsistent colors for array size printout

[Dev-iL]

When displaying a struct containing non-scalar arrays, something like the following is printed out:

ans = 

      form: 'pp'
    breaks: [1x40 double]
     coefs: [39x4 double]
    pieces: 39
     order: 4
       dim: 1

This gets highlighted as follows (example in SO):

Note the x40 and x4. I would either expect everything to be black, or all numbers to be brown and x's to be black.

[amroamroamro]

Actually I think the highlighted output is not wrong here!

You see prettify-matlab is expected to highlight valid MATLAB code, but the snippet you showed is not correct code in itself, rather an output of some function (disp in this case).

Obviously if you attempt to run it in MATLAB prompt you get an error as you'd expect:

>> [1x40 double]
 [1x40 double]
   |
Error: Unexpected MATLAB expression.

Even GitHub highlighting is indicating a syntax error with red (variable names must start with a letter).

So when it sees the expression [1x40 double] it's making a best effort at parsing it as valid code:

<span class="tag">[</span>
<span class="lit">1</span>
<span class="ident">x40</span>
<span class="pln"> </span>
<span class="typ">double</span>
<span class="tag">]</span>

i.e there's a number 1 followed by a token/variable called x40, whitespace and then the double type, all contained in an array definition [..]. I don't see how else the expression could be parsed...