#604 Add a function for creating positions needed for supporting highlights across many lines

2 files changed, 100 insertions, 0 deletions

diff --git a/autoload/ale/highlight.vim b/autoload/ale/highlight.vim
index 2240c595..7807c8da 100644
--- a/autoload/ale/highlight.vim
+++ b/autoload/ale/highlight.vim
@@ -28,6 +28,30 @@ endif
 " the buffer is in focus when linting completes.
 let s:buffer_highlights = {}
 let s:buffer_restore_map = {}
+" The maximum number of items for the second argument of matchaddpos()
+let s:MAX_POS_VALUES = 8
+let s:MAX_COL_SIZE = 4294967296
+
+function! ale#highlight#CreatePositions(line, col, end_line, end_col) abort
+    if a:line >= a:end_line
+        " For single lines, just return the one position.
+        return [[[a:line, a:col, a:end_col - a:col + 1]]]
+    endif
+
+    " Get positions from the first line at the first column, up to a large
+    " integer for highlighting up to the end of the line, followed by
+    " the lines in-between, for highlighting entire lines, and
+    " a highlight for the last line, up to the end column.
+    let l:all_positions =
+    \   [[a:line, a:col, s:MAX_COL_SIZE]]
+    \   + range(a:line + 1, a:end_line - 1)
+    \   + [[a:end_line, 1, a:end_col]]
+
+    return map(
+    \   range(0, len(l:all_positions) - 1, s:MAX_POS_VALUES),
+    \   'l:all_positions[v:val : v:val + s:MAX_POS_VALUES - 1]',
+    \)
+endfunction
 
 function! ale#highlight#UnqueueHighlights(buffer) abort
     if has_key(s:buffer_highlights, a:buffer)
diff --git a/test/test_highlight_position_chunking.vader b/test/test_highlight_position_chunking.vader
new file mode 100644
index 00000000..120e294d
--- /dev/null
+++ b/test/test_highlight_position_chunking.vader
@@ -0,0 +1,76 @@
+Execute(CreatePositions() should support single character matches):
+  AssertEqual [[[1, 5, 1]]], ale#highlight#CreatePositions(1, 5, 1, 5)
+  " When the end column is behind the start column, ignore it.
+  AssertEqual [[[2, 5, 1]]], ale#highlight#CreatePositions(2, 5, 1, 5)
+
+Execute(CreatePositions() should support multiple character matches on a single line):
+  AssertEqual [[[1, 5, 6]]], ale#highlight#CreatePositions(1, 5, 1, 10)
+  " When the end column is behind the start column, ignore it.
+  AssertEqual [[[2, 5, 6]]], ale#highlight#CreatePositions(2, 5, 1, 10)
+
+Execute(CreatePositions() should support character matches two lines):
+  AssertEqual [[[1, 5, 4294967296], [2, 1, 10]]], ale#highlight#CreatePositions(1, 5, 2, 10)
+
+Execute(CreatePositions() should support character matches across many lines):
+  " Test chunks from 1,3 to 1,17
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, [3, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 3, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, [4, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 4, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, [5, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 5, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, [6, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 6, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, [7, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 7, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, [8, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 8, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [[9, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 9, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, [10, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 10, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, [11, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 11, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, 11, [12, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 12, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, 11, 12, [13, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 13, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, 11, 12, 13, [14, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 14, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, 11, 12, 13, 14, [15, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 15, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, 11, 12, 13, 14, 15, [16, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 16, 10)
+  AssertEqual [
+  \ [[1, 5, 4294967296], 2, 3, 4, 5, 6, 7, 8],
+  \ [9, 10, 11, 12, 13, 14, 15, 16],
+  \ [[17, 1, 10]],
+  \], ale#highlight#CreatePositions(1, 5, 17, 10)
+  " Test another random sample at higher lines.
+  AssertEqual [
+  \ [[21, 8, 4294967296], 22, 23, 24, 25, 26, 27, 28],
+  \ [29, 30, 31, 32, 33, 34, 35, 36],
+  \ [[37, 1, 2]],
+  \], ale#highlight#CreatePositions(21, 8, 37, 2)