Implement new magic frontend using sexpr

3 files changed, 104 insertions, 7 deletions

diff --git a/src/io/line.cpp b/src/io/line.cpp
index fb73f45..8173398 100644
--- a/src/io/line.cpp
+++ b/src/io/line.cpp
@@ -32,7 +32,7 @@
 
 namespace io
 {
-    AString Line::message_str(ZString cat, ZString msg)
+    AString Line::message_str(ZString cat, ZString msg) const
     {
         MString out;
         if (column)
@@ -46,7 +46,7 @@ namespace io
         return AString(out);
     }
 
-    void Line::message(ZString cat, ZString msg)
+    void Line::message(ZString cat, ZString msg) const
     {
         if (column)
             FPRINTF(stderr, "%s:%u:%u: %s: %s\n",
@@ -58,6 +58,45 @@ namespace io
         FPRINTF(stderr, "%*c\n", column, '^');
     }
 
+    AString LineSpan::message_str(ZString cat, ZString msg) const
+    {
+        assert (begin.column);
+        assert (end.column);
+        assert (begin.column <= end.column);
+
+        MString out;
+        if (begin.line == end.line)
+        {
+            out += STRPRINTF("%s:%u:%u: %s: %s\n",
+                    begin.filename, begin.line, begin.column, cat, msg);
+            out += STRPRINTF("%s\n", begin.text);
+            out += STRPRINTF("%*c", begin.column, '^');
+            for (unsigned c = begin.column; c != end.column; ++c)
+                out += '~';
+            out += '\n';
+        }
+        else
+        {
+            out += STRPRINTF("%s:%u:%u: %s: %s\n",
+                    begin.filename, begin.line, begin.column, cat, msg);
+            out += STRPRINTF("%s\n", begin.text);
+            out += STRPRINTF("%*c", begin.column, '^');
+            for (unsigned c = begin.column; c != begin.text.size(); ++c)
+                out += '~';
+            out += " ...\n";
+            out += STRPRINTF("%s\n", end.text);
+            for (unsigned c = 0; c != end.column; ++c)
+                out += '~';
+            out += '\n';
+        }
+        return AString(out);
+    }
+
+    void LineSpan::message(ZString cat, ZString msg) const
+    {
+        FPRINTF(stderr, "%s", message_str(cat, msg));
+    }
+
     LineReader::LineReader(ZString name)
     : filename(name), line(0), column(0), rf(name)
     {}
diff --git a/src/io/line.hpp b/src/io/line.hpp
index 321cdf7..a9e8944 100644
--- a/src/io/line.hpp
+++ b/src/io/line.hpp
@@ -40,11 +40,11 @@ namespace io
         // 1-based
         uint16_t line, column;
 
-        AString message_str(ZString cat, ZString msg);
-        void message(ZString cat, ZString msg);
-        void note(ZString msg) { message("note", msg); }
-        void warning(ZString msg) { message("warning", msg); }
-        void error(ZString msg) { message("error", msg); }
+        AString message_str(ZString cat, ZString msg) const;
+        void message(ZString cat, ZString msg) const;
+        void note(ZString msg) const { message("note", msg); }
+        void warning(ZString msg) const { message("warning", msg); }
+        void error(ZString msg) const { message("error", msg); }
     };
 
     // psst, don't tell anyone
@@ -59,6 +59,17 @@ namespace io
         }
     };
 
+    struct LineSpan
+    {
+        LineChar begin, end;
+
+        AString message_str(ZString cat, ZString msg) const;
+        void message(ZString cat, ZString msg) const;
+        void note(ZString msg) const { message("note", msg); }
+        void warning(ZString msg) const { message("warning", msg); }
+        void error(ZString msg) const { message("error", msg); }
+    };
+
     class LineReader
     {
     protected:
diff --git a/src/io/line_test.cpp b/src/io/line_test.cpp
index ae316c6..6f0706f 100644
--- a/src/io/line_test.cpp
+++ b/src/io/line_test.cpp
@@ -348,3 +348,50 @@ TEST(io, linechar5)
     lr.adv();
     EXPECT_FALSE(lr.get(c));
 }
+
+TEST(io, linespan)
+{
+    io::LineCharReader lr("<span>", string_pipe("Hello\nWorld\n"));
+    io::LineSpan span;
+    do
+    {
+        lr.get(span.begin);
+        lr.adv();
+    }
+    while (span.begin.ch() != 'e');
+    do
+    {
+        lr.get(span.end);
+        lr.adv();
+    }
+    while (span.end.ch() != 'o');
+    EXPECT_EQ(span.message_str("info", "meh"),
+            "<span>:1:2: info: meh\n"
+            "Hello\n"
+            " ^~~~\n"
+    );
+    do
+    {
+        lr.get(span.end);
+        lr.adv();
+    }
+    while (span.end.ch() != 'r');
+
+    EXPECT_EQ(span.begin.message_str("note", "foo"),
+            "<span>:1:2: note: foo\n"
+            "Hello\n"
+            " ^\n"
+    );
+    EXPECT_EQ(span.end.message_str("warning", "bar"),
+            "<span>:2:3: warning: bar\n"
+            "World\n"
+            "  ^\n"
+    );
+    EXPECT_EQ(span.message_str("error", "qux"),
+            "<span>:1:2: error: qux\n"
+            "Hello\n"
+            " ^~~~ ...\n"
+            "World\n"
+            "~~~\n"
+    );
+}