Add basic scripting support.

- Fix certain bugs in ruby parser
- And a lot more cleanup/minor fixes.

src/internal/functions/posix.cc

@@ -37,7 +37,19 @@ void Function::register_posix(BEd &ctx) {
       .desc = "Append text to a line",
       .default_address = ".",
       .accept_zero = true,
-      .pre_text_mode = nullptr,
+      .pre_text_mode = [](
+                         BEd &ctx,
+                         const buffer::Address &addr_,
+                         const Argument &
+                       ) -> std::tuple<vase::Shard *, syntax::Language *, void *> {
+        const auto &addr = std::get<buffer::Line>(addr_);
+        auto &buf_ = ctx.buffer(addr.buffername);
+        if (buf_.kind != buffer::Buffer::Kind::Generic)
+          return {nullptr, nullptr, nullptr};
+        auto &buf = *(buffer::GenericBuffer *)&buf_;
+        void *state = syntax::state_before(buf.parse, buf.root, addr.number);
+        return {nullptr, buf.parse.lang, state};
+      },
       .handle = [](
                   BEd &ctx,
                   const buffer::Address &addr_,
@@ -47,8 +59,7 @@ void Function::register_posix(BEd &ctx) {
                 ) {
         auto addr = std::get<buffer::Line>(addr_);
         ctx.buffer(addr.buffername).append(ctx, text, addr.number);
-        vase::Shard::release(text);
-      }
+        vase::Shard::release(text); }
     }
   );
   ctx.functions.insert(
@@ -70,9 +81,7 @@ void Function::register_posix(BEd &ctx) {
         if (buf_.kind != buffer::Buffer::Kind::Generic)
           return {buf_.copy(addr.start, addr.end), nullptr, nullptr};
         auto &buf = *(buffer::GenericBuffer *)&buf_;
-        if (!buf.parse.lang)
-          return {buf.copy(addr.start, addr.end), nullptr, nullptr};
-        void *state = nullptr; // TODO: buf.parse.root.get_at(addr.start);
+        void *state = syntax::state_before(buf.parse, buf.root, addr.start - 1);
         return {buf.copy(addr.start, addr.end), buf.parse.lang, state};
       },
       .handle = [](
@@ -291,7 +300,21 @@ void Function::register_posix(BEd &ctx) {
       .desc = "Insert text before a line",
       .default_address = ".",
       .accept_zero = true,
-      .pre_text_mode = nullptr,
+      .pre_text_mode = [](
+                         BEd &ctx,
+                         const buffer::Address &addr_,
+                         const Argument &
+                       ) -> std::tuple<vase::Shard *, syntax::Language *, void *> {
+        auto addr = std::get<buffer::Line>(addr_);
+        if (addr.number)
+          addr.number--;
+        auto &buf_ = ctx.buffer(addr.buffername);
+        if (buf_.kind != buffer::Buffer::Kind::Generic)
+          return {nullptr, nullptr, nullptr};
+        auto &buf = *(buffer::GenericBuffer *)&buf_;
+        void *state = syntax::state_before(buf.parse, buf.root, addr.number);
+        return {nullptr, buf.parse.lang, state};
+      },
       .handle = [](
                   BEd &ctx,
                   const buffer::Address &addr_,
@@ -303,8 +326,7 @@ void Function::register_posix(BEd &ctx) {
         if (addr.number)
           addr.number--;
         ctx.buffer(addr.buffername).append(ctx, text, addr.number);
-        vase::Shard::release(text);
-      }
+        vase::Shard::release(text); }
     }
   );
   ctx.functions.insert(