diff options
Diffstat (limited to 'stream.sml')
| -rw-r--r-- | stream.sml | 54 |
1 files changed, 35 insertions, 19 deletions
@@ -1,9 +1,16 @@ structure Stream :> STREAM = struct type fileId = int type fileOffset = int + type fileInfo = fileId * string * string + + type t = fileId * string * fileOffset * string + type pos = fileId * fileOffset type ppos = string * int * int option - type fileInfo = fileId * string * string + + type pposCache = + { id: fileId, fname: string, contents: string, + offset: fileOffset, line: int, col: int } exception UngetcError exception InvalidFileInfo @@ -17,31 +24,21 @@ structure Stream :> STREAM = struct | NONE => pos ^ ":" ^ %line end - type t = fileId * string * fileOffset * string - fun convert (fid, fname, _, contents) = (fid, fname, contents) - fun calcFilePos s offset = + fun calcFilePos (startOff, startPos) contents destOff = let - fun calc s cur offset (line, col) = - if cur = offset then + fun calc offset (line, col) = + if offset = destOff then (line, col) else - calc s (cur + 1) offset - (if String.sub (s, cur) = #"\n" then (line + 1, 1) - else (line, col + 1)) + calc (offset + 1) (if String.sub (contents, offset) = #"\n" + then (line + 1, 1) else (line, col + 1)) in - calc s 0 offset (1, 1) + calc startOff startPos end - fun printPos (_, fname, contents) (_, pos) = - let - val (line, col) = calcFilePos contents pos - val line = Int.toString line - val col = Int.toString col - in - print $ fname ^ ":" ^ line ^ ":" ^ col ^ ": " - end + val calcFilePosFromStart = calcFilePos (0, (1, 1)) fun getchar (S as (fid, fname, off, contents)) = if off < String.size contents then @@ -62,7 +59,7 @@ structure Stream :> STREAM = struct raise InvalidFileInfo else let - val (line, col) = calcFilePos contents pos + val (line, col) = calcFilePosFromStart contents pos in (fname, line, SOME col) end @@ -105,4 +102,23 @@ structure Stream :> STREAM = struct in returnToNL (offset - 1) end + + fun pposCacheInit (id, fname, contents) = + { id, fname, contents, offset = 0, line = 1, col = 1 } + + fun pposCacheAdvance (id, pos) (cache: pposCache) = + if id <> #id cache then + raise Unreachable + else + let + fun ` f = f cache + val p as (line, col) = calcFilePos (` #offset, (` #line, ` #col)) + (` #contents) pos + in + (p, { id = ` #id, fname = ` #fname, contents = ` #contents, + offset = pos, line, col }) + end + + fun pposCacheGetLine (cache: pposCache) = #line cache + fun pposCacheGetFname (cache: pposCache) = #fname cache end |