heptagon/global/location.ml

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OCaml
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2010-06-15 10:49:03 +02:00
(* Printing a location in the source program *)
(* taken from the source of the Caml Light 0.73 compiler *)
open Lexing
open Parsing
(* two important global variables: [input_name] and [input_chan] *)
type location =
Loc of int (* Position of the first character *)
* int (* Position of the next character following the last one *)
let input_name = ref "" (* Input file name. *)
let input_chan = ref stdin (* The channel opened on the input. *)
let initialize iname ic =
input_name := iname;
input_chan := ic
let no_location = Loc(0,0)
let error_prompt = ">"
let get_current_location () =
Loc(symbol_start(), symbol_end())
let output_lines oc char1 char2 charline1 line1 line2 =
let n1 = char1 - charline1
and n2 = char2 - charline1 in
if line2 > line1 then
Printf.fprintf oc
", line %d-%d, characters %d-%d:\n" line1 line2 n1 n2
else
Printf.fprintf oc ", line %d, characters %d-%d:\n" line1 n1 n2;
()
let output_loc oc input seek line_flag (Loc(pos1, pos2)) =
let pr_chars n c =
for i = 1 to n do output_char oc c done in
let skip_line () =
try
while input() != '\n' do () done
with End_of_file -> () in
let copy_line () =
let c = ref ' ' in
begin try
while c := input(); !c != '\n' do output_char oc !c done
with End_of_file ->
output_string oc "<EOF>"
end;
output_char oc '\n' in
let pr_line first len ch =
let c = ref ' '
and f = ref first
and l = ref len in
try
while c := input (); !c != '\n' do
if !f > 0 then begin
f := !f - 1;
output_char oc (if !c == '\t' then !c else ' ')
end
else if !l > 0 then begin
l := !l - 1;
output_char oc (if !c == '\t' then !c else ch)
end
else ()
done
with End_of_file ->
if !f = 0 && !l > 0 then pr_chars 5 ch in
let pos = ref 0
and line1 = ref 1
and line1_pos = ref 0
and line2 = ref 1
and line2_pos = ref 0 in
seek 0;
begin try
while !pos < pos1 do
incr pos;
if input() == '\n' then begin incr line1; line1_pos := !pos; () end
done
with End_of_file -> ()
end;
line2 := !line1;
line2_pos := !line1_pos;
begin try
while !pos < pos2 do
incr pos;
if input() == '\n' then
begin incr line2; line2_pos := !pos; () end
done
with End_of_file -> ()
end;
if line_flag then output_lines oc pos1 pos2 !line1_pos !line1 !line2;
if !line1 == !line2 then begin
seek !line1_pos;
output_string oc error_prompt;
copy_line ();
seek !line1_pos;
output_string oc error_prompt;
pr_line (pos1 - !line1_pos) (pos2 - pos1) '^';
output_char oc '\n'
end else begin
seek !line1_pos;
output_string oc error_prompt;
pr_line 0 (pos1 - !line1_pos) '.';
seek pos1;
copy_line();
if !line2 - !line1 <= 8 then
for i = !line1 + 1 to !line2 - 1 do
output_string oc error_prompt;
copy_line()
done
else
begin
for i = !line1 + 1 to !line1 + 3 do
output_string oc error_prompt;
copy_line()
done;
output_string oc error_prompt; output_string oc "..........\n";
for i = !line1 + 4 to !line2 - 4 do skip_line() done;
for i = !line2 - 3 to !line2 - 1 do
output_string oc error_prompt;
copy_line()
done
end;
begin try
output_string oc error_prompt;
for i = !line2_pos to pos2 - 1 do
output_char oc (input())
done;
pr_line 0 100 '.'
with End_of_file -> output_string oc "<EOF>"
end;
output_char oc '\n'
end
let output_location oc loc =
let p = pos_in !input_chan in
Printf.fprintf oc "File \"%s\"" !input_name;
output_loc
oc (fun () -> input_char !input_chan) (seek_in !input_chan) true
loc;
seek_in !input_chan p
let output_input_name oc =
Printf.fprintf oc "File \"%s\", line 1:\n" !input_name