json-api: add location array to error and warning objects

curv/export.cc

@@ -16,6 +16,7 @@
 #include <libcurv/exception.h>
 #include <libcurv/filesystem.h>
 #include <libcurv/format.h>
+#include <libcurv/json.h>
 #include <libcurv/program.h>
 #include <libcurv/range.h>
 #include <libcurv/source.h>
@@ -208,16 +209,6 @@ bool is_json_data(Value val)
         return true; // null, bool or num
     }
 }
-void export_json_string(const char* str, std::ostream& out)
-{
-    out << '"';
-    for (const char* p = str; *p != '\0'; ++p) {
-        if (*p == '\\' || *p == '"')
-            out << '\\';
-        out << *p;
-    }
-    out << '"';
-}
 bool export_json_value(Value val, std::ostream& out, const Context& cx)
 {
     if (val.is_null()) {
@@ -238,7 +229,7 @@ bool export_json_value(Value val, std::ostream& out, const Context& cx)
     case Ref_Value::ty_string:
       {
         auto& str = (String&)ref;
-        export_json_string(str.c_str(), out);
+        write_json_string(str.c_str(), out);
         return true;
       }
     case Ref_Value::ty_list:
@@ -267,7 +258,7 @@ bool export_json_value(Value val, std::ostream& out, const Context& cx)
             if (is_json_data(val)) {
                 if (!first) out << ",";
                 first = false;
-                export_json_string(id.c_str(), out);
+                write_json_string(id.c_str(), out);
                 out << ":";
                 export_json_value(val, out, At_Field(id.c_str(), cx));
             }
@@ -325,7 +316,7 @@ void export_json_api(Value value,
                 << "," << dfmt(shape.bbox_.ymax, dfmt::JSON)
                 << "," << dfmt(shape.bbox_.zmax, dfmt::JSON)
             << "]],\"shader\":";
-        export_json_string(vshape.frag_.c_str(), ofile.ostream());
+        write_json_string(vshape.frag_.c_str(), ofile.ostream());
         ofile.ostream() << "}}\n";
     }
 }

libcurv/json.cc

@@ -0,0 +1,20 @@
+// Copyright 2016-2018 Doug Moen
+// Licensed under the Apache License, version 2.0
+// See accompanying file LICENSE or https://www.apache.org/licenses/LICENSE-2.0
+
+#include <libcurv/json.h>
+
+namespace curv {
+
+void write_json_string(const char* str, std::ostream& out)
+{
+    out << '"';
+    for (const char* p = str; *p != '\0'; ++p) {
+        if (*p == '\\' || *p == '"')
+            out << '\\';
+        out << *p;
+    }
+    out << '"';
+}
+
+} // namespace curv

libcurv/json.h

@@ -0,0 +1,15 @@
+// Copyright 2016-2018 Doug Moen
+// Licensed under the Apache License, version 2.0
+// See accompanying file LICENSE or https://www.apache.org/licenses/LICENSE-2.0
+
+#ifndef LIBCURV_JSON_H
+#define LIBCURV_JSON_H
+
+#include <ostream>
+
+namespace curv {
+
+void write_json_string(const char*, std::ostream&);
+
+} // namespace curv
+#endif // header guard

libcurv/location.cc

@@ -6,6 +6,7 @@
 
 #include <libcurv/ansi_colour.h>
 #include <libcurv/format.h>
+#include <libcurv/json.h>
 
 namespace curv {
 
@@ -181,6 +182,18 @@ Location::write(std::ostream& out, bool colour, bool many) const
     }
 }
 
+void
+Location::write_json(std::ostream& out) const
+{
+    out << "{\"byte_range\":["
+        << token().first_ << "," << token().last_ << "]";
+    if (!filename().empty()) {
+        out << ",\"filename\":";
+        write_json_string(filename().c_str(), out);
+    }
+    out << "}";
+}
+
 Range<const char*>
 Location::range() const
 {

libcurv/location.h

@@ -56,6 +56,8 @@ struct Location
     /// The `colour` flag enables colour text using ANSI ESC sequences.
     void write(std::ostream&, bool colour, bool many) const;
 
+    void write_json(std::ostream&) const;
+
     /// Line and column information for a Location
     ///
     /// Line and column numbers begin at 0.

libcurv/system.cc

@@ -8,6 +8,7 @@
 #include <libcurv/context.h>
 #include <libcurv/exception.h>
 #include <libcurv/import.h>
+#include <libcurv/json.h>
 #include <libcurv/program.h>
 #include <libcurv/source.h>
 
@@ -31,26 +32,23 @@ void System::print_exception(
     out << std::endl;
 }
 
-static void export_json_string(const char* str, std::ostream& out)
-{
-    out << '"';
-    for (const char* p = str; *p != '\0'; ++p) {
-        if (*p == '\\' || *p == '"')
-            out << '\\';
-        out << *p;
-    }
-    out << '"';
-}
-
 void System::print_json_exception(
     const char* type, const std::exception& exc, std::ostream& out)
 {
     out << "{\"" << type << "\":{";
     out << "\"message\":";
-    export_json_string(exc.what(), out);
+    write_json_string(exc.what(), out);
     const Exception *e = dynamic_cast<const Exception*>(&exc);
-    if (e) {
+    if (e && !e->loc_.empty()) {
         // print location array
+        out << ",\"location\":[";
+        bool first = true;
+        for (auto L : e->loc_) {
+            if (!first) out << ",";
+            first = false;
+            L.write_json(out);
+        }
+        out << "]";
     }
     out << "}}" << std::endl;
 }
@@ -75,7 +73,7 @@ void System::print(const char* str)
 {
     if (use_json_api_) {
         console() << "{\"print\":";
-        export_json_string(str, console());
+        write_json_string(str, console());
         console() << "}";
     } else {
         console() << str;