Add reactors to the JSON parser

14 files changed, 250 insertions, 5 deletions

diff --git a/libtests/json_parse.cc b/libtests/json_parse.cc
index 77692eab..7f894c8d 100644
--- a/libtests/json_parse.cc
+++ b/libtests/json_parse.cc
@@ -1,21 +1,113 @@
 #include <qpdf/JSON.hh>
 #include <qpdf/QUtil.hh>
+#include <cstdlib>
+#include <cstring>
 #include <iostream>
+#include <memory>
+
+namespace
+{
+    class Reactor: public JSON::Reactor
+    {
+      public:
+        virtual ~Reactor() = default;
+        virtual void dictionaryStart() override;
+        virtual void arrayStart() override;
+        virtual void containerEnd(JSON const& value) override;
+        virtual void topLevelScalar() override;
+        virtual bool
+        dictionaryItem(std::string const& key, JSON const& value) override;
+        virtual bool arrayItem(JSON const& value) override;
+
+      private:
+        void printItem(JSON const&);
+    };
+} // namespace
+
+void
+Reactor::dictionaryStart()
+{
+    std::cout << "dictionary start" << std::endl;
+}
+
+void
+Reactor::arrayStart()
+{
+    std::cout << "array start" << std::endl;
+}
+
+void
+Reactor::containerEnd(JSON const& value)
+{
+    std::cout << "container end: ";
+    printItem(value);
+}
+
+void
+Reactor::topLevelScalar()
+{
+    std::cout << "top-level scalar" << std::endl;
+}
+
+bool
+Reactor::dictionaryItem(std::string const& key, JSON const& value)
+{
+    std::cout << "dictionary item: " << key << " -> ";
+    printItem(value);
+    if (key == "keep") {
+        return false;
+    }
+    return true;
+}
+
+bool
+Reactor::arrayItem(JSON const& value)
+{
+    std::cout << "array item: ";
+    printItem(value);
+    std::string n;
+    if (value.getString(n) && n == "keep") {
+        return false;
+    }
+    return true;
+}
+
+void
+Reactor::printItem(JSON const& j)
+{
+    std::cout << "[" << j.getStart() << ", " << j.getEnd()
+              << "): " << j.unparse() << std::endl;
+}
+
+static void
+usage()
+{
+    std::cerr << "Usage: json_parse file [--react]" << std::endl;
+    exit(2);
+}
 
 int
 main(int argc, char* argv[])
 {
-    if (argc != 2) {
-        std::cerr << "Usage: json_parse file" << std::endl;
+    if ((argc < 2) || (argc > 3)) {
+        usage();
         return 2;
     }
     char const* filename = argv[1];
+    std::shared_ptr<Reactor> reactor;
+    if (argc == 3) {
+        if (strcmp(argv[2], "--react") == 0) {
+            reactor = std::make_shared<Reactor>();
+        } else {
+            usage();
+        }
+    }
     try {
         std::shared_ptr<char> buf;
         size_t size;
         QUtil::read_file_into_memory(filename, buf, size);
         std::string s(buf.get(), size);
-        std::cout << JSON::parse(s).unparse() << std::endl;
+        std::cout << JSON::parse(s, reactor.get()).unparse() << std::endl;
     } catch (std::exception& e) {
         std::cerr << "exception: " << filename << ": " << e.what() << std::endl;
         return 2;
diff --git a/libtests/qtest/json_parse.test b/libtests/qtest/json_parse.test
index cdafb506..15b251cc 100644
--- a/libtests/qtest/json_parse.test
+++ b/libtests/qtest/json_parse.test
@@ -32,7 +32,7 @@ if ($^O ne 'msys')
 
 cleanup();
 
-my $good = 9;
+my $good = 10;
 
 for (my $i = 1; $i <= $good; ++$i)
 {
@@ -73,6 +73,11 @@ for (my $i = 1; $i <= $good; ++$i)
                      {$td->FILE => "out.json"},
                      {$td->STRING => ""});
     }
+
+    $td->runtest("good $n reactor",
+                 {$td->COMMAND => "json_parse good-$n.json --react"},
+                 {$td->FILE => "good-$n-react.out", $td->EXIT_STATUS => 0},
+                 $td->NORMALIZE_NEWLINES);
 }
 
 my @bad = (
@@ -127,7 +132,7 @@ foreach my $d (@bad)
 
 cleanup();
 
-$td->report((2 * $good) + scalar(@bad));
+$td->report((3 * $good) + scalar(@bad));
 
 sub cleanup
 {
diff --git a/libtests/qtest/json_parse/good-01-react.out b/libtests/qtest/json_parse/good-01-react.out
new file mode 100644
index 00000000..d6167a6b
--- /dev/null
+++ b/libtests/qtest/json_parse/good-01-react.out
@@ -0,0 +1,21 @@
+dictionary start
+dictionary item: a -> [6, 11): "bcd"
+array start
+dictionary item: e -> [18, 0): []
+array item: [19, 20): 1
+array item: [41, 42): 2
+array item: [44, 45): 3
+array item: [46, 47): 4
+array item: [48, 54): "five"
+dictionary start
+array item: [56, 0): {}
+dictionary item: six -> [64, 65): 7
+dictionary item: 8 -> [72, 73): 9
+container end: [56, 74): {}
+array item: [76, 80): null
+array item: [82, 86): true
+array item: [107, 112): false
+array item: [114, 134): "a\b\f\n\r\t\\\"/z"
+container end: [18, 135): []
+container end: [0, 136): {}
+{}
diff --git a/libtests/qtest/json_parse/good-02-react.out b/libtests/qtest/json_parse/good-02-react.out
new file mode 100644
index 00000000..12d1931a
--- /dev/null
+++ b/libtests/qtest/json_parse/good-02-react.out
@@ -0,0 +1,3 @@
+dictionary start
+container end: [0, 2): {}
+{}
diff --git a/libtests/qtest/json_parse/good-03-react.out b/libtests/qtest/json_parse/good-03-react.out
new file mode 100644
index 00000000..02e632b7
--- /dev/null
+++ b/libtests/qtest/json_parse/good-03-react.out
@@ -0,0 +1,3 @@
+array start
+container end: [0, 2): []
+[]
diff --git a/libtests/qtest/json_parse/good-04-react.out b/libtests/qtest/json_parse/good-04-react.out
new file mode 100644
index 00000000..bd18ccfc
--- /dev/null
+++ b/libtests/qtest/json_parse/good-04-react.out
@@ -0,0 +1,18 @@
+array start
+array start
+array item: [1, 0): []
+array start
+array item: [2, 0): []
+dictionary start
+array item: [3, 0): {}
+container end: [3, 5): {}
+container end: [2, 6): []
+dictionary start
+array item: [8, 0): {}
+dictionary start
+dictionary item:  -> [13, 0): {}
+container end: [13, 15): {}
+container end: [8, 16): {}
+container end: [1, 17): []
+container end: [0, 18): []
+[]
diff --git a/libtests/qtest/json_parse/good-05-react.out b/libtests/qtest/json_parse/good-05-react.out
new file mode 100644
index 00000000..daa37173
--- /dev/null
+++ b/libtests/qtest/json_parse/good-05-react.out
@@ -0,0 +1,2 @@
+top-level scalar
+"x"
diff --git a/libtests/qtest/json_parse/good-06-react.out b/libtests/qtest/json_parse/good-06-react.out
new file mode 100644
index 00000000..adec78ee
--- /dev/null
+++ b/libtests/qtest/json_parse/good-06-react.out
@@ -0,0 +1,2 @@
+top-level scalar
+123
diff --git a/libtests/qtest/json_parse/good-07-react.out b/libtests/qtest/json_parse/good-07-react.out
new file mode 100644
index 00000000..e08bca41
--- /dev/null
+++ b/libtests/qtest/json_parse/good-07-react.out
@@ -0,0 +1,2 @@
+top-level scalar
+-123
diff --git a/libtests/qtest/json_parse/good-08-react.out b/libtests/qtest/json_parse/good-08-react.out
new file mode 100644
index 00000000..c773d585
--- /dev/null
+++ b/libtests/qtest/json_parse/good-08-react.out
@@ -0,0 +1,11 @@
+array start
+array item: [1, 2): 1
+array item: [4, 6): -2
+array item: [8, 11): 3.4
+array item: [13, 17): -5.6
+array item: [19, 23): -9e1
+array item: [25, 29): 10e2
+array item: [31, 37): 12.3e5
+array item: [39, 46): 12.6e-7
+container end: [0, 47): []
+[]
diff --git a/libtests/qtest/json_parse/good-09-react.out b/libtests/qtest/json_parse/good-09-react.out
new file mode 100644
index 00000000..edbf869b
--- /dev/null
+++ b/libtests/qtest/json_parse/good-09-react.out
@@ -0,0 +1,8 @@
+array start
+array item: [1, 7): "aπb"
+array item: [9, 23): "a\b\f\n\r\tc"
+array item: [25, 42): "aπbπc"
+array item: [44, 52): "π"
+array item: [54, 71): "a\u0018bʬc"
+container end: [0, 72): []
+[]
diff --git a/libtests/qtest/json_parse/good-10-react.out b/libtests/qtest/json_parse/good-10-react.out
new file mode 100644
index 00000000..142d95d0
--- /dev/null
+++ b/libtests/qtest/json_parse/good-10-react.out
@@ -0,0 +1,47 @@
+dictionary start
+array start
+dictionary item: a -> [9, 0): []
+array item: [10, 11): 1
+array item: [13, 14): 2
+dictionary start
+array item: [16, 0): {}
+dictionary item: x -> [22, 25): "y"
+container end: [16, 26): {}
+array item: [28, 29): 3
+dictionary start
+array item: [31, 0): {}
+dictionary item: keep -> [40, 61): "not in final output"
+container end: [31, 62): {
+  "keep": "not in final output"
+}
+container end: [9, 63): []
+array start
+dictionary item: keep -> [75, 0): []
+array item: [76, 77): 1
+array item: [79, 83): null
+array item: [85, 86): 2
+array item: [88, 93): false
+array item: [95, 101): "keep"
+array item: [103, 104): 3
+array start
+array item: [106, 0): []
+array item: [107, 113): "this"
+array item: [115, 121): "keep"
+array item: [123, 128): "not"
+array item: [130, 137): "final"
+container end: [106, 138): [
+  "keep"
+]
+container end: [75, 139): [
+  "keep"
+]
+container end: [0, 141): {
+  "keep": [
+    "keep"
+  ]
+}
+{
+  "keep": [
+    "keep"
+  ]
+}
diff --git a/libtests/qtest/json_parse/good-10.json b/libtests/qtest/json_parse/good-10.json
new file mode 100644
index 00000000..8f2d46b3
--- /dev/null
+++ b/libtests/qtest/json_parse/good-10.json
@@ -0,0 +1,4 @@
+{
+  "a": [1, 2, {"x": "y"}, 3, {"keep": "not in final output"}],
+  "keep": [1, null, 2, false, "keep", 3, ["this", "keep", "not", "final"]]
+}
diff --git a/libtests/qtest/json_parse/save-10.json b/libtests/qtest/json_parse/save-10.json
new file mode 100644
index 00000000..1b111dbd
--- /dev/null
+++ b/libtests/qtest/json_parse/save-10.json
@@ -0,0 +1,27 @@
+{
+  "a": [
+    1,
+    2,
+    {
+      "x": "y"
+    },
+    3,
+    {
+      "keep": "not in final output"
+    }
+  ],
+  "keep": [
+    1,
+    null,
+    2,
+    false,
+    "keep",
+    3,
+    [
+      "this",
+      "keep",
+      "not",
+      "final"
+    ]
+  ]
+}