From c792986768a2f3d42fc6113fb8b5459fdbf5a0fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dan=20Ros=C3=A9n?= <dan.rosen@gu.se>
Date: Tue, 22 Oct 2019 21:14:32 +0200
Subject: [PATCH] Teach JSON parser negative numbers

---
 src/json_ui.cc | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/json_ui.cc b/src/json_ui.cc
index ebb3b7bf..a0294f3e 100644
--- a/src/json_ui.cc
+++ b/src/json_ui.cc
@@ -257,7 +257,7 @@ void JsonUI::set_on_key(OnKeyCallback callback)
 using JsonArray = Vector<Value>;
 using JsonObject = HashMap<String, Value>;
 
-static bool is_digit(char c) { return c >= '0' and c <= '9'; }
+static bool is_digit_or_minus(char c) { return (c >= '0' and c <= '9') or c == '-'; }
 
 struct JsonResult { Value value; const char* new_pos; };
 
@@ -266,10 +266,10 @@ JsonResult parse_json(const char* pos, const char* end)
     if (not skip_while(pos, end, is_blank))
         return {};
 
-    if (is_digit(*pos))
+    if (is_digit_or_minus(*pos))
     {
         auto digit_end = pos;
-        skip_while(digit_end, end, is_digit);
+        skip_while(digit_end, end, is_digit_or_minus);
         return { Value{str_to_int({pos, digit_end})}, digit_end };
     }
     if (end - pos > 4 and StringView{pos, pos+4} == "true")
@@ -523,6 +523,11 @@ UnitTest test_json_parser{[]()
         kak_assert(value.as<JsonArray>().at(1).as<int>() == 20);
     }
 
+    {
+        auto value = parse_json("-1").value;
+        kak_assert(value.as<int>() == -1);
+    }
+
     {
         auto value = parse_json("{}").value;
         kak_assert(value and value.is_a<JsonObject>());