lines and offsets properties (#291)

lib/kernel/comby_kernel.mli

@@ -343,6 +343,13 @@ module Matchers : sig
     type kind =
       | Value
       | Length
+      | Lines
+      | OffsetStart
+      | OffsetEnd
+      | LineStart
+      | LineEnd
+      | ColumnStart
+      | ColumnEnd
       | LsifHover
       | FileName
       | FilePath

lib/kernel/matchers/template.ml

@@ -78,6 +78,16 @@ module Make (Metasyntax : Types.Metasyntax.S) = struct
   let attribute_to_kind = function
     | "value" -> Value
     | "length" -> Length
+    | "lines" -> Lines
+    | "offset"
+    | "offset.start" -> OffsetStart
+    | "offset.end" -> OffsetEnd
+    | "line"
+    | "line.start" -> LineStart
+    | "line.end" -> LineEnd
+    | "column"
+    | "column.start" -> ColumnStart
+    | "column.end" -> ColumnEnd
     | "lsif.hover" -> LsifHover
     | "file.path" -> FilePath
     | "file.name" -> FileName
@@ -96,6 +106,16 @@ module Make (Metasyntax : Types.Metasyntax.S) = struct
     char '.' *> choice
       [ string "value"
       ; string "length"
+      ; string "lines"
+      ; string "offset.start"
+      ; string "offset.end"
+      ; string "offset"
+      ; string "line.start"
+      ; string "line.end"
+      ; string "line"
+      ; string "column.start"
+      ; string "column.end"
+      ; string "column"
       ; string "lsif.hover"
       ; string "file.path"
       ; string "file.name"
@@ -192,6 +212,55 @@ module Make (Metasyntax : Types.Metasyntax.S) = struct
     match kind with
     | Value -> Environment.lookup env variable
     | Length -> Environment.lookup env variable >>| length_to_string
+    | Lines ->
+      Environment.lookup env variable
+      >>| String.count ~f:(Char.(=) '\n')
+      >>| (fun v -> if v = 0 then 1 else v)
+      >>| Int.to_string
+
+    | OffsetStart ->
+      Environment.lookup_range env variable
+      >>| fun { match_start = { offset; _ }; _ } ->
+      Int.to_string offset
+    | OffsetEnd ->
+      Environment.lookup_range env variable
+      >>| fun { match_end = { offset; _ }; _ } ->
+      Int.to_string offset
+
+    | LineStart ->
+      filepath >>= fun filepath ->
+      Environment.lookup_range env variable
+      >>| fun { match_start = { offset; _ }; _ } ->
+      let source = In_channel.read_all filepath in (* Inefficient. *)
+      let index = Match.Offset.index ~source in
+      let line, _ = Match.Offset.convert_fast ~offset index in
+      Int.to_string line
+    | LineEnd ->
+      filepath >>= fun filepath ->
+      Environment.lookup_range env variable
+      >>| fun { match_end = { offset; _ }; _ } ->
+      let source = In_channel.read_all filepath in (* Inefficient. *)
+      let index = Match.Offset.index ~source in
+      let line, _ = Match.Offset.convert_fast ~offset index in
+      Int.to_string line
+
+    | ColumnStart ->
+      filepath >>= fun filepath ->
+      Environment.lookup_range env variable
+      >>| fun { match_start = { offset; _ }; _ } ->
+      let source = In_channel.read_all filepath in (* Inefficient. *)
+      let index = Match.Offset.index ~source in
+      let _, column = Match.Offset.convert_fast ~offset index in
+      Int.to_string column
+    | ColumnEnd ->
+      filepath >>= fun filepath ->
+      Environment.lookup_range env variable
+      >>| fun { match_end = { offset; _ }; _ } ->
+      let source = In_channel.read_all filepath in (* Inefficient. *)
+      let index = Match.Offset.index ~source in
+      let _, column = Match.Offset.convert_fast ~offset index in
+      Int.to_string column
+
     | LsifHover ->
       filepath >>= fun filepath ->
       if debug then Format.printf "File for lsif.hover lookup: %s@." filepath;

lib/kernel/matchers/types.ml

@@ -125,6 +125,13 @@ module Template = struct
   type kind =
     | Value
     | Length
+    | Lines
+    | OffsetStart
+    | OffsetEnd
+    | LineStart
+    | LineEnd
+    | ColumnStart
+    | ColumnEnd
     | LsifHover
     | FileName
     | FilePath

test/common/test_rewrite_attributes.ml

@@ -70,3 +70,105 @@ let%expect_test "filepath_rule" =
   [%expect_exact {|ok: this/is/a/path|}];
   run (module Matchers.Omega.Generic) ~filepath source ~rule match_template "ok: :[x]";
   [%expect_exact {|ok: this/is/a/path|}]
+
+let%expect_test "lines" =
+  let source = {|
+    {
+      foo
+    }
+    {
+      bar
+      baz
+    }
+|} in
+  let match_template = "{:[x]}" in
+  let rewrite_template = {|:[x].lines|}
+  in
+  run (module Matchers.Alpha.Generic) source match_template rewrite_template;
+  [%expect_exact {|
+    2
+    3
+|}];
+  run (module Matchers.Omega.Generic) source match_template rewrite_template;
+  [%expect_exact {|
+    2
+    3
+|}]
+
+let%expect_test "offsets" =
+  let source = {|
+first
+<  >things
+<     >first
+|} in
+  let match_template = ":[[x]]" in
+  let rewrite_template = {|
+offset: :[[x]].offset
+offset.start: :[[x]].offset.start
+offset.end: :[[x]].offset.end
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+|}
+  in
+  run (module Matchers.Alpha.Generic) source match_template rewrite_template;
+  [%expect_exact {|
+
+offset: 1
+offset.start: 1
+offset.end: 6
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+
+<  >
+offset: 11
+offset.start: 11
+offset.end: 17
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+
+<     >
+offset: 25
+offset.start: 25
+offset.end: 30
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+
+|}];
+  run (module Matchers.Omega.Generic) source match_template rewrite_template;
+  [%expect_exact {|
+
+offset: 1
+offset.start: 1
+offset.end: 6
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+
+<  >
+offset: 11
+offset.start: 11
+offset.end: 17
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+
+<     >
+offset: 25
+offset.start: 25
+offset.end: 30
+line.start: :[[x]].line.start     // can't compute without source yet
+line.end: :[[x]].line.end         // can't compute without source yet
+column.start: :[[x]].column.start // can't compute without source yet
+column.end: :[[x]].column.end     // can't compute without source yet
+
+|}]