9fc2614f |
1 | (* This file comes mostly from "Modern Compiler Implementation in ML," by Andrew Appel |
2 | * http://www.cs.princeton.edu/~appel/modern/ml/ |
3 | *) |
4 | |
5 | structure ErrorMsg :> ERRORMSG = |
6 | struct |
7 | (* Initial values of compiler state variables *) |
8 | val anyErrors = ref false |
9 | val errorText = ref "" |
10 | val fileName = ref "" |
11 | val lineNum = ref 1 |
12 | val linePos = ref [1] |
13 | val sourceStream = ref TextIO.stdIn |
14 | |
15 | fun print msg = (errorText := !errorText ^ msg; |
16 | TextIO.print msg) |
17 | |
18 | (* Reset compiler to initial state *) |
19 | fun reset() = (anyErrors:=false; |
20 | errorText:=""; |
21 | fileName:=""; |
22 | lineNum:=1; |
23 | linePos:=[1]; |
24 | sourceStream:=TextIO.stdIn) |
25 | |
26 | (* Print the given error message *) |
27 | fun error posopt (msg:string) = |
28 | let |
29 | val (startpos, endpos) = Option.getOpt (posopt, (0, 0)) |
30 | fun look(pos,a::rest,n) = |
31 | if a<pos then app print [Int.toString n, |
32 | ".", |
33 | Int.toString (pos-a)] |
34 | else look(pos,rest,n-1) |
35 | | look _ = print "0.0" |
36 | in |
37 | anyErrors := true; |
38 | print (!fileName); print ":"; |
39 | look(startpos, !linePos, !lineNum); |
40 | if startpos=endpos then () else (print "-"; look(endpos, !linePos, !lineNum)); |
41 | app print [":error: ", msg, "\n"] |
42 | end |
43 | |
44 | val dummyLoc = (0, 0) |
45 | |
46 | exception Error |
47 | end |
48 | |