1 files changed, 122 insertions, 0 deletions
diff --git a/server/src/parser/lines.lua b/server/src/parser/lines.lua
new file mode 100644
index 00000000..ea41e927
--- /dev/null
+++ b/server/src/parser/lines.lua
@@ -0,0 +1,122 @@
+local m = require 'lpeglabel'
+
+local function utf8_len(buf, start, finish)
+    local len, pos = utf8.len(buf, start, finish)
+    if len then
+        return len
+    end
+    return 1 + utf8_len(buf, start, pos-1) + utf8_len(buf, pos+1, finish)
+end
+
+local function Line(pos, str, ...)
+    local line = {...}
+    local sp = 0
+    local tab = 0
+    for i = 1, #line do
+        if line[i] == ' ' then
+            sp = sp + 1
+        else
+            tab = tab + 1
+        end
+        line[i] = nil
+    end
+    line[1] = pos
+    line[2] = sp
+    line[3] = tab
+    return line
+end
+
+local parser = m.P{
+'Lines',
+Lines   = m.Ct(m.V'Line'^0 * m.V'LastLine'),
+Line    = m.Cp() * m.C(m.V'Indent' * (1 - m.V'Nl')^0 * m.V'Nl') / Line,
+LastLine= m.Cp() * m.C(m.V'Indent' * (1 - m.V'Nl')^0) / Line,
+Nl      = m.P'\r\n' + m.S'\r\n',
+Indent  = m.C(m.S' \t')^0,
+}
+
+local mt = {}
+mt.__index = mt
+
+function mt:position(row, col, code)
+    if row < 1 then
+        return 1
+    end
+    if row > #self then
+        if code == 'utf8' then
+            return utf8_len(self.buf) + 1
+        else
+            return #self.buf + 1
+        end
+    end
+    local line = self[row]
+    local next_line = self[row+1]
+    local start = line[1]
+    local finish
+    if next_line then
+        finish = next_line[1] - 1
+    else
+        finish = #self.buf + 1
+    end
+    local pos
+    if code == 'utf8' then
+        pos = utf8.offset(self.buf, col, start) or finish
+    else
+        pos = start + col - 1
+    end
+    if pos < start then
+        pos = start
+    elseif pos > finish then
+        pos = finish
+    end
+    return pos
+end
+
+function mt:rowcol(pos, code)
+    if pos < 1 then
+        return 1, 1
+    end
+    if pos > #self.buf + 1 then
+        local start = self[#self][1]
+        if code == 'utf8' then
+            return #self, utf8_len(self.buf, start) + 1
+        else
+            return #self, #self.buf - start + 2
+        end
+    end
+    local min = 1
+    local max = #self
+    for _ = 1, 100 do
+        local row = (max - min) // 2 + min
+        local start = self[row][1]
+        if pos < start then
+            max = row
+        elseif pos > start then
+            local next_start = self[row + 1][1]
+            if pos < next_start then
+                if code == 'utf8' then
+                    return row, utf8_len(self.buf, start, pos)
+                else
+                    return row, pos - start + 1
+                end
+            elseif pos > next_start then
+                min = row
+            else
+                return row + 1, 1
+            end
+        else
+            return row, 1
+        end
+    end
+    error('rowcol failed!')
+end
+
+return function (self, buf)
+    local lines, err = parser:match(buf)
+    if not lines then
+        return nil, err
+    end
+    lines.buf = buf
+
+    return setmetatable(lines, mt)
+end