fix: correct tokenizer greediness with subtraction and division

lib/Template/Parser.pm

@@ -626,10 +626,14 @@ sub tokenise_directive {
                 \2                       # match opening quote
             |
                 # an unquoted number matches in $4
-                (-?\d+(?:\.\d+)?)       # numbers
+                # only treat leading - as unary when not after a
+                # word char, close-paren, or close-bracket (else
+                # it is a subtraction operator, e.g. x-2)
+                ((?:(?<![)\]\w])-)?  \d+(?:\.\d+)?)   # numbers
             |
-                # filename matches in $5
-                ( \/?\w+(?:(?:\/|::?)\w*)+ | \/\w+)
+                # filename matches in $5 — path segments after
+                # the separator must start with a letter
+                ( \/?\w+(?:(?:\/|::?)[a-zA-Z_]\w*)+ | \/[a-zA-Z_]\w+)
             |
                 # an identifier matches in $6
                 (\w+)                    # variable identifier

t/binop.t

@@ -327,7 +327,19 @@ mega: 106
 3 3
 
 
--- stop -- 
+-- test --
+-- name subtraction vs negative literal (GH #315) --
+[% x = 10; y = x - 3 %][% y +%]
+[% z = -5 %][% z +%]
+[% a = x + -2 %][% a +%]
+[% b = x - -2 %][% b %]
+-- expect --
+7
+-5
+8
+12
+
+-- stop --
 # this is for testing the lt operator which isn't enabled by default.
 -- test --
 [% IF 'one' lt 'two' -%]

t/macro.t

@@ -163,3 +163,13 @@ two: 2[The Title] -> one: 2[The Title]
 [% triple(10) %]
 -- expect --
 30
+
+-- test --
+-- name macro with arithmetic expressions (GH #315) --
+[% MACRO show(n) BLOCK -%]
+[% n %]
+[%- END -%]
+[% x = 5 -%]
+[% show(x) %]:[% show(x+2) %]:[% show(x-2) %]:[% show(x*2) %]:[% show(x/2) %]
+-- expect --
+5:7:3:10:2.5