Latex bug with minus and Mul

[proy87]

Latex printer can't handle expressions like -(x+5).

from sympy.printing.latex import latex
from sympy.abc import x
from sympy import Mul
expr = Mul(-1,x+5, evaluate=False)
latex(expr) # outputs -x+5 instead of -(x+5)

I looked int code and found

        if denom is S.One:
            # use the original expression here, since fraction() may have
            # altered it when producing numer and denom
            tex += convert(expr)

convert returns simple addition (since minus was previously taken and now x+5 is_Add), then minus is simply prepended.

[Sumith1896]

What answer is expected?
Is it -(x + 5) or - ( x + 5 ) or something else?

[debugger22]

See this: latex(expr) # outputs -x+5 instead of -(x+5)

[Sumith1896]

Before fix it's printing - x + 5, I just wanted to confirm the exact output required(proper spacing)?

[debugger22]

I think it should be - x - 5 because autosimplification will -(x + 5) will simplify it.

[Sumith1896]

But evaluate is set to False.

[debugger22]

Oh sorry! Then I think - (x + 5) should be fine.

[debugger22]

Actually I'm not sure because pretty printer gives this -(x + 5)

[proy87]

Answer should be -(x+5). Printer should print expression, not evaluate and print.

[debugger22]

@simamura87 the confusion is about the space after -.

[proy87]

Latex ignores implicit whitespaces, isn't it?

[tokencolour]

Why is this issue still open?

[gxyd]

Closing. Fixed by #10889.