fix _not_strings for substring overlaps

common/json-schema-to-grammar.cpp

@@ -429,12 +429,12 @@ private:
                     out << " | ";
                 }
                 out << "[" << kv.first << "]";
-                if (kv.second.is_end_of_string) {
+                if (!kv.second.children.empty()) {
-                    out << " " << char_rule << "+";
-                } else {
                     out << " (";
                     visit(kv.second);
                     out << ")";
+                } else if (kv.second.is_end_of_string) {
+                    out << " " << char_rule << "+";
                 }
             }
             if (!node.children.empty()) {
@@ -446,7 +446,11 @@ private:
         };
         visit(trie);
 
-        out << " )? [\"] space";
+        out << " )";
+        if (!trie.is_end_of_string) {
+            out << "?";
+        }
+        out << " [\"] space";
         return out.str();
     }
 

examples/json_schema_to_grammar.py

@@ -142,12 +142,12 @@ class SchemaConverter:
                 else:
                     out.append(' | ')
                 out.append(f'[{c}]')
-                if (child.is_end_of_string):
+                if child.children:
-                    out.append(f' {char_rule}+')
-                else:
                     out.append(f' (')
                     visit(child)
                     out.append(')')
+                elif child.is_end_of_string:
+                    out.append(f' {char_rule}+')
             if node.children:
                 if not first:
                     out.append(' | ')

examples/server/public/json-schema-to-grammar.mjs

@@ -367,18 +367,19 @@ export class SchemaConverter {
       for (const c of Object.keys(node.children).sort()) {
         const child = node.children[c];
         rejects.push(c);
-        if (!first) {
+        if (first) {
+          first = false;
+        } else {
           out.push(' | ');
         }
         out.push(`[${c}]`);
-        if (child.isEndOfString) {
+        if (Object.keys(child.children).length > 0) {
-          out.push(` ${charRuleName}+`);
-        } else {
           out.push(' (');
           visit(child);
           out.push(')');
+        } else if (child.isEndOfString) {
+          out.push(` ${charRuleName}+`);
         }
-        first = false;
       }
       if (Object.keys(node.children).length > 0) {
         if (!first) {

tests/test-json-schema-to-grammar.cpp

@@ -697,6 +697,82 @@ static void test_all(const std::string & lang, std::function<void(const TestCase
         )"""
     });
 
+    test({
+        SUCCESS,
+        "optional props with empty name",
+        R"""({
+            "properties": {
+                "": {"type": "integer"},
+                "a": {"type": "integer"}
+            },
+            "additionalProperties": {"type": "integer"}
+        })""",
+        R"""(
+            -kv ::= "\"\"" space ":" space root
+            -rest ::= ( "," space a-kv )? a-rest
+            a-kv ::= "\"a\"" space ":" space integer
+            a-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] char+ | [^"a] char* ) ["] space
+            additional-kv ::= additional-k ":" space integer
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
+            integer ::= ("-"? integral-part) space
+            integral-part ::= [0] | [1-9] [0-9]{0,15}
+            root ::= ("-"? integral-part) space
+            root0 ::= "{" space  (-kv -rest | a-kv a-rest | additional-kv ( "," space additional-kv )* )? "}" space
+            space ::= | " " | "\n" [ \t]{0,20}
+        )"""
+    });
+
+    test({
+        SUCCESS,
+        "optional props with nested names",
+        R"""({
+            "properties": {
+                "a": {"type": "integer"},
+                "aa": {"type": "integer"}
+            },
+            "additionalProperties": {"type": "integer"}
+        })""",
+        R"""(
+            a-kv ::= "\"a\"" space ":" space integer
+            a-rest ::= ( "," space aa-kv )? aa-rest
+            aa-kv ::= "\"aa\"" space ":" space integer
+            aa-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] ([a] char+ | [^"a] char*) | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space integer
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
+            integer ::= ("-"? integral-part) space
+            integral-part ::= [0] | [1-9] [0-9]{0,15}
+            root ::= "{" space  (a-kv a-rest | aa-kv aa-rest | additional-kv ( "," space additional-kv )* )? "}" space
+            space ::= | " " | "\n" [ \t]{0,20}
+        )"""
+    });
+
+    test({
+        SUCCESS,
+        "optional props with common prefix",
+        R"""({
+            "properties": {
+                "ab": {"type": "integer"},
+                "ac": {"type": "integer"}
+            },
+            "additionalProperties": {"type": "integer"}
+        })""",
+        R"""(
+            ab-kv ::= "\"ab\"" space ":" space integer
+            ab-rest ::= ( "," space ac-kv )? ac-rest
+            ac-kv ::= "\"ac\"" space ":" space integer
+            ac-rest ::= ( "," space additional-kv )*
+            additional-k ::= ["] ( [a] ([b] char+ | [c] char+ | [^"bc] char*) | [^"a] char* )? ["] space
+            additional-kv ::= additional-k ":" space integer
+            char ::= [^"\\\x7F\x00-\x1F] | [\\] (["\\bfnrt] | "u" [0-9a-fA-F]{4})
+            integer ::= ("-"? integral-part) space
+            integral-part ::= [0] | [1-9] [0-9]{0,15}
+            root ::= "{" space  (ab-kv ab-rest | ac-kv ac-rest | additional-kv ( "," space additional-kv )* )? "}" space
+            space ::= | " " | "\n" [ \t]{0,20}
+        )"""
+    });
+
     test({
         SUCCESS,
         "top-level $ref",