Improve pretty printing of unary minus sign

sharkdp · Apr 6, 2017 · 3eb2bb4 · 3eb2bb4
1 parent be1000a
commit 3eb2bb4
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/src/Insect/PrettyPrint.purs b/src/Insect/PrettyPrint.purs
@@ -98,8 +98,7 @@ pretty ∷ Expression → Markup
 pretty (Scalar n)                      = prettyScalar n
 pretty (Unit u)                        = prettyUnit u
 pretty (Variable name)                 = prettyVariable name
-pretty (Negate (Scalar s))             = F.text "-" : prettyScalar s
-pretty (Negate x)                      = F.text "-(" : pretty x <> [ F.text ")" ]
+pretty (Negate x)                      = F.text "-" : withParens x
 pretty (Apply fn x)                    = prettyApply fn x
 -- ConvertTo (->) never needs parens, it has the lowest precedence:
 pretty (BinOp ConvertTo x y)           = pretty x <> prettyOp ConvertTo <> pretty y

diff --git a/test/Main.purs b/test/Main.purs
@@ -635,6 +635,9 @@ main = runTest do
       prettyPrintCheck "(2m)^3"
       prettyPrintCheck "(2m)^(3kg)"
       prettyPrintCheck "(2m)^(3kg)^((4in)^(5ft))^(6s)"
+      prettyPrintCheck "-sqrt(-30m^3)"
+      prettyPrintCheck "-3^4"
+      prettyPrintCheck "(-3)^4"
 
     test "Format" do
       equalPretty "2 + 3" "2+3"