diff options
Diffstat (limited to 'lua')
| -rw-r--r-- | lua/vis.lua | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/lua/vis.lua b/lua/vis.lua index 24d00bd..f18792e 100644 --- a/lua/vis.lua +++ b/lua/vis.lua @@ -190,4 +190,35 @@ end vis.events = events +--- +-- @type File + +--- Check whether LPeg pattern matches at a given file position. +-- @function match_at +-- @param pattern the LPeg pattern +-- @tparam int the absolute position in bytes to test for a match +-- @tparam[opt] int horizon the number of bytes around `pos` to consider (defaults to 1K) +-- @treturn int start,end the range of the matched region or `nil` +vis.types['vis.file'].match_at = function(file, pattern, pos, horizon) + horizon = horizon or 1024 + local lpeg = vis.lpeg + if not lpeg then return nil end + local before, after = pos - horizon, pos + horizon + if before < 0 then before = 0 end + local data = file:content(before, after - before) + local string_pos = pos - before + 1 + + local I = lpeg.Cp() + local p = lpeg.P{ I * pattern * I + 1 * lpeg.V(1) } + local s, e = 1 + while true do + s, e = p:match(data, s) + if not s then return nil end + if s <= string_pos and string_pos < e then + return before + s - 1, before + e - 1 + end + s = e + end +end + require('vis-std') |