BUG: LaTeX pretty-print omits parentheses around negative literals.

AlgebraicJulia · Dec 14, 2018 · f208551 · f208551
1 parent 0660527
commit f208551
Show file tree

Hide file tree

Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/algebra/Tree.jl b/src/algebra/Tree.jl
@@ -247,10 +247,11 @@ function show_latex_formula(io::IO, bool::Bool; kw...)
 end
 
 function show_latex_formula(io::IO, num::Number; kw...)
-  if isinf(num)
-    show_latex_formula(io, num > 0 ? :Inf : Formula(:-, :Inf))
+  if num < 0
+    # Treat negative literals as compound expressions.
+    show_latex_formula(io, Formula(:-, abs(num)); kw...)
   else
-    print(io, num)
+    print(io, isinf(num) ? "\\infty" : num)
   end
 end
 

diff --git a/test/algebra/Tree.jl b/test/algebra/Tree.jl
@@ -92,6 +92,7 @@ sexpr(form::Formula) = sprint(show_sexpr, form)
 @test latex(Formula((:-, (:+, :x, :y)))) == "- \\left(x + y\\right)"
 @test_skip latex(Formula((:+, :x, (:-, :y)))) == "x + \\left(- y\\right)"
 @test latex(Formula((:factorial, (:*, :m, :n)))) == "\\left(m n\\right) !"
+@test latex(Formula(:^, -1, :n)) == "\\left(- 1\\right)^{n}"
 
 # S-expression pretty-print.
 @test sexpr(Formula(:f)) == "(:f)"