1 files changed, 93 insertions, 0 deletions
diff --git a/script/parser/calcline.lua b/script/parser/calcline.lua
new file mode 100644
index 00000000..26f475d9
--- /dev/null
+++ b/script/parser/calcline.lua
@@ -0,0 +1,93 @@
+local m = require 'lpeglabel'
+
+local row
+local fl
+local NL = (m.P'\r\n' + m.S'\r\n') * m.Cp() / function (pos)
+    row = row + 1
+    fl = pos
+end
+local ROWCOL = (NL + m.P(1))^0
+local function rowcol(str, n)
+    row = 1
+    fl = 1
+    ROWCOL:match(str:sub(1, n))
+    local col = n - fl + 1
+    return row, col
+end
+
+local function rowcol_utf8(str, n)
+    row = 1
+    fl = 1
+    ROWCOL:match(str:sub(1, n))
+    return row, utf8.len(str, fl, n)
+end
+
+local function position(str, _row, _col)
+    local cur = 1
+    local row = 1
+    while true do
+        if row == _row then
+            return cur + _col - 1
+        elseif row > _row then
+            return cur - 1
+        end
+        local pos = str:find('[\r\n]', cur)
+        if not pos then
+            return #str
+        end
+        row = row + 1
+        if str:sub(pos, pos+1) == '\r\n' then
+            cur = pos + 2
+        else
+            cur = pos + 1
+        end
+    end
+end
+
+local function position_utf8(str, _row, _col)
+    local cur = 1
+    local row = 1
+    while true do
+        if row == _row then
+            return utf8.offset(str, _col, cur)
+        elseif row > _row then
+            return cur - 1
+        end
+        local pos = str:find('[\r\n]', cur)
+        if not pos then
+            return #str
+        end
+        row = row + 1
+        if str:sub(pos, pos+1) == '\r\n' then
+            cur = pos + 2
+        else
+            cur = pos + 1
+        end
+    end
+end
+
+local NL = m.P'\r\n' + m.S'\r\n'
+
+local function line(str, row)
+    local count = 0
+    local res
+    local LINE = m.Cmt((1 - NL)^0, function (_, _, c)
+        count = count + 1
+        if count == row then
+            res = c
+            return false
+        end
+        return true
+    end)
+    local MATCH = (LINE * NL)^0 * LINE
+    MATCH:match(str)
+    return res
+end
+
+return {
+    rowcol = rowcol,
+    rowcol_utf8 = rowcol_utf8,
+    position = position,
+    position_utf8 = position_utf8,
+    line = line,
+}