lexer: Handle differentation between zero and prefix

Signed-off-by: Ian Moffett <ian@mirocom.org>

core/lexer.c

@@ -26,6 +26,22 @@ lexer_is_ws(char c)
     return false;
 }
 
+/*
+ * Returns true if the given character is apart of a numbering
+ * system prefix (e.g., '0x' or 'o0')
+ */
+static inline bool
+lexer_is_num_prefix(char c)
+{
+    switch (c) {
+    case 'o':
+    case 'x':
+        return true;
+    }
+
+    return false;
+}
+
 /*
  * Place a given character into the putback buffer
  *
@@ -355,8 +371,8 @@ lexer_scan_num(struct rifle_state *state, int lc, struct token *tok)
     if (lc == '0') {
         if ((prefix = lexer_nom(state, false)) == '\0')
             return -1;
-        if ((lc = lexer_nom(state, false)) == '\0')
+        if (!lexer_is_num_prefix(prefix))
-            return -1;
+            lexer_putback(state, prefix);
     }
 
     /*
@@ -367,9 +383,15 @@ lexer_scan_num(struct rifle_state *state, int lc, struct token *tok)
      */
     switch (prefix) {
     case 'x':
+        if ((lc = lexer_nom(state, false)) == '\0')
+            return -1;
+
         radix = 16;
         break;
     case 'o':
+        if ((lc = lexer_nom(state, false)) == '\0')
+            return -1;
+
         radix = 8;
         break;
     default: