Printing Options

The 2 + 1 print modes of Oscar

Oscar has two user print modes detailed and one line and one internal print mode terse. The latter is for use during recursion, e.g. to print the base_ring(X) when in one line mode. It exists to make sure that one line stays compact and human readable.

Top-level REPL printing of an object will use detailed mode by default

julia> X
detailed

Inside nested structures, e.g. inside a Vector, the one line mode is used.

julia> [X,X]
3-element Vector{TypeofX{T}}
one line
one line
one line

An Example for the 2 + 1 print modes

# detailed
julia> E = elliptic_curve(QQ, [-82, 0])
Elliptic curve
  over rational field
with equation
  y^2 = x^3 - 82*x

# one line
julia> println(E)
Elliptic curve over QQ with equation y^2 = x^3 - 82*x

# terse
julia> println(Oscar.terse(stdout),E)
Elliptic curve

Unicode printing

Per default the output will be ASCII only (no Unicode). Implementors of Base.show and related functions can branch on the output of is_unicode_allowed() to display objects using non-ASCII characters. This will then be used, if users have enabled Unicode using allow_unicode(true).

allow_unicode — Method

allow_unicode(allowed::Bool; temporary::Bool=false) -> Bool

Set whether unicode characters are allowed in pretty printing and returns the previous value. If temporary is true, then the change is only active for the current worker and session. Otherwise, the change is permanently saved in the preferences. A permanent change will always override a temporary change.

This function may behave arbitrarily if called from within the scope of a with_unicode do-block.

See also is_unicode_allowed and with_unicode.

source

with_unicode — Function

with_unicode(f::Function, allowed::Bool=true)

Temporarily set whether unicode characters are allowed in pretty printing during the execution of f. This is useful for e.g. running doctests independently on the user preference.

with_unicode is expected to be called in the following way:

with_unicode([allowed]) do
   # code that should be executed with unicode allowed/disallowed
end

source

is_unicode_allowed — Method

is_unicode_allowed() -> Bool

Return whether unicode characters are allowed in pretty printing.

See also allow_unicode and with_unicode.

source

Objects may follow the value of is_unicode_allowed() at the time of their creation for their printing, i.e. ignore later changes of the setting. This is useful for objects storing a string representation of themselves, e.g. generators of a module.

Here is an example with and without output using Unicode:

julia> allow_unicode(false);

julia> R, (x,y) = QQ[:x,:y];

julia> Q,_ = quo(R,ideal([x,y]));

julia> variety(Q)
Affine variety
  in affine 2-space over QQ with coordinates [x, y]
defined by ideal (x, y)

julia> allow_unicode(true);

julia> variety(Q)
Affine variety
  in 𝔸² over QQ with coordinates [x, y]
defined by ideal (x, y)

LaTeX and HTML printing

Some types support LaTeX or HTML output:

julia> Qx, x = QQ[:x];

julia> show(stdout, "text/latex", x^2 + 2x + x^10)
x^{10} + x^{2} + 2 x

julia> show(stdout, "text/html", x^2 + 2x + x^10)
x^10 + x^2 + 2*x

julia> show(stdout, "text/latex", Qx[x x^2; 1 1])
\begin{array}{cc}
x & x^{2} \\
1 & 1
\end{array}

Note: While using IJulia, you can enable LaTeX rendering in Jupyter notebooks using the following function:

julia> Qx, x = QQ[:x];

julia> AbstractAlgebra.set_html_as_latex(true);

julia> show(stdout, "text/html", x^2 + 2x + x^10)
$x^{10} + x^{2} + 2 x$