allow spaces between sign and number, when parsing

hledger-lib/Hledger/Read/Common.hs

@@ -688,8 +688,10 @@ amountp' s =
 mamountp' :: String -> MixedAmount
 mamountp' = Mixed . (:[]) . amountp'
 
+-- | Parse a minus or plus sign followed by zero or more spaces,
+-- or nothing, returning a function that negates or does nothing.
 signp :: Num a => TextParser m (a -> a)
-signp = char '-' *> pure negate <|> char '+' *> pure id <|> pure id
+signp = ((char '-' *> pure negate <|> char '+' *> pure id) <* many spacenonewline) <|> pure id
 
 multiplierp :: TextParser m Bool
 multiplierp = option False $ char '*' *> pure True

hledger-lib/hledger_journal.m4.md

@@ -421,12 +421,18 @@ must be enclosed in double quotes:
 
     3 "no. 42 green apples"
 
-Amounts can be negative. The minus sign can be written before or after
+Amounts can be preceded by a minus sign (or a plus sign, though plus is the default),
-a left-side commodity symbol:
+The sign can be written before or after a left-side commodity symbol:
 
     -$1
     $-1
 
+One or more spaces between the sign and the number are acceptable
+when parsing (but they won't be displayed in output):
+
+    + $1
+    $-      1
+
 Scientific E notation is allowed:
 
     1E-6