Abbreviated non-MIME show() for GreenNode (#581)

Non-MIME `show()` for `GreenNode` was using the default implementation
which is extremely verbose. Here we print it as an S-expression instead.
I've made a choice to show absolute position within the parent node
rather than node span so that it directly relates to indices in the
string it was derived from.

Author: c42f

src/porcelain/green_node.jl

@@ -118,6 +118,25 @@ function Base.show(io::IO, ::MIME"text/plain", node::GreenNode, str::AbstractStr
     _show_green_node(io, node, "", 1, str, show_trivia)
 end
 
+function _show_green_node_sexpr(io, node::GreenNode, position)
+    if is_leaf(node)
+        print(io, position, "-", position+node.span-1, "::", untokenize(head(node); unique=false))
+    else
+        print(io, "(", untokenize(head(node); unique=false))
+        p = position
+        for n in children(node)
+            print(io, ' ')
+            _show_green_node_sexpr(io, n, p)
+            p += n.span
+        end
+        print(io, ')')
+    end
+end
+
+function Base.show(io::IO, node::GreenNode)
+    _show_green_node_sexpr(io, node, 1)
+end
+
 function GreenNode(cursor::GreenTreeCursor)
     chead = head(cursor)
     T = typeof(chead)

src/porcelain/syntax_tree.jl

@@ -250,11 +250,9 @@ function _show_syntax_node_sexpr(io, node::AbstractSyntaxNode, show_kind)
         end
     else
         print(io, "(", untokenize(head(node)))
-        first = true
         for n in children(node)
             print(io, ' ')
             _show_syntax_node_sexpr(io, n, show_kind)
-            first = false
         end
         print(io, ')')
     end

test/green_node.jl

@@ -62,4 +62,7 @@
         10:10     │  Identifier             ✔   "z"
         11:11     │  )                          ")"
     """
+
+    @test sprint(show, parsestmt(GreenNode, "a + bb - f(ccc)")) ==
+        "(call-i (call-i 1-1::Identifier 2-2::Whitespace-t 3-3::Identifier 4-4::Whitespace-t 5-6::Identifier) 7-7::Whitespace-t 8-8::Identifier 9-9::Whitespace-t (call 10-10::Identifier 11-11::(-t 12-14::Identifier 15-15::)-t))"
 end