1 files changed, 187 insertions, 0 deletions
diff --git a/script/parser/lines.lua b/script/parser/lines.lua
new file mode 100644
index 00000000..f2f076e1
--- /dev/null
+++ b/script/parser/lines.lua
@@ -0,0 +1,187 @@
+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(start, line, finish)
+    line.start  = start
+    line.finish = finish - 1
+    return line
+end
+
+local function Space(...)
+    local line = {...}
+    local sp = 0
+    local tab = 0
+    for i = 1, #line do
+        if line[i] == ' ' then
+            sp = sp + 1
+        elseif line[i] == '\t' then
+            tab = tab + 1
+        end
+        line[i] = nil
+    end
+    line.sp  = sp
+    line.tab = tab
+    return line
+end
+
+local parser = m.P{
+'Lines',
+Lines   = m.Ct(m.V'Line'^0 * m.V'LastLine'),
+Line    = m.Cp() * m.V'Indent' * (1 - m.V'Nl')^0 * m.Cp() * m.V'Nl' / Line,
+LastLine= m.Cp() * m.V'Indent' * (1 - m.V'Nl')^0 * m.Cp() / Line,
+Nl      = m.P'\r\n' + m.S'\r\n',
+Indent  = m.C(m.S' \t')^0 / Space,
+}
+
+local mt = {}
+mt.__index = mt
+
+function mt:position(row, col, code)
+    if row < 1 then
+        return 1
+    end
+    code = code or self.code
+    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.start
+    local finish
+    if next_line then
+        finish = next_line.start - 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
+
+local function isCharByte(byte)
+    if not byte then
+        return false
+    end
+    -- [0-9]
+    if byte >= 48 and byte <= 57 then
+        return true
+    end
+    -- [A-Z]
+    if byte >= 65 and byte <= 90 then
+        return true
+    end
+    -- [a-z]
+    if byte >= 97 and byte <= 122 then
+        return true
+    end
+    -- <utf8>
+    if byte >= 128 then
+        return true
+    end
+    return false
+end
+
+function mt:positionAsChar(row, col, code)
+    local pos = self:position(row, col, code)
+    if isCharByte(self.buf:byte(pos, pos)) then
+        return pos
+    elseif isCharByte(self.buf:byte(pos+1, pos+1)) then
+        return pos + 1
+    end
+    return pos
+end
+
+function mt:rowcol(pos, code)
+    if pos < 1 then
+        return 1, 1
+    end
+    code = code or self.code
+    if pos >= #self.buf + 1 then
+        local start = self[#self].start
+        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
+        if max == min then
+            local start = self[min].start
+            if code == 'utf8' then
+                return min, utf8_len(self.buf, start, pos)
+            else
+                return min, pos - start + 1
+            end
+        end
+        local row = (max - min) // 2 + min
+        local start = self[row].start
+        if pos < start then
+            max = row
+        elseif pos > start then
+            local next_start = self[row + 1].start
+            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 + 1
+            else
+                return row + 1, 1
+            end
+        else
+            return row, 1
+        end
+    end
+    error('rowcol failed!')
+end
+
+function mt:line(i)
+    local start, finish = self:range(i)
+    return self.buf:sub(start, finish)
+end
+
+function mt:range(i)
+    if i < 1 or i > #self then
+        return 0, 0
+    end
+    return self[i].start, self[i].finish
+end
+
+function mt:set_code(code)
+    self.code = code
+end
+
+return function (self, buf, code)
+    local lines, err = parser:match(buf)
+    if not lines then
+        return nil, err
+    end
+    lines.buf = buf
+    lines.code = code
+
+    return setmetatable(lines, mt)
+end