NPGSCommandUtilImpl.Mesa
Copyright Ó 1985, 1992 by Xerox Corporation. All rights reserved.
Satterthwaite, December 10, 1982 10:47 am
Maxwell, August 29, 1983 8:11 am
Paul Rovner, December 2, 1983 5:35 pm
Russ Atkinson (RRA) March 7, 1985 4:26:00 am PST
Andy Litman May 31, 1988 10:34:19 pm PDT
JKF February 6, 1989 12:12:06 pm PST
Michael Plass, December 10, 1992 10:19 pm PST
DIRECTORY
Ascii USING [Lower],
NPGSCommandUtil USING [PairList, Switches],
IO USING [GetChar, GetIndex, PutChar, PutRope, SetIndex, STREAM, EndOfStream],
Rope
USING [Cat, Concat, Equal, Fetch, Find, FromChar, Length,
ROPE, Substr];
NPGSCommandUtilImpl:
CEDAR PROGRAM
IMPORTS Ascii, IO, Rope
EXPORTS NPGSCommandUtil = {
PairList: TYPE = NPGSCommandUtil.PairList;
ROPE: TYPE = Rope.ROPE;
TokenClass:
TYPE =
CHAR;
id: TokenClass = 'I;
eom: TokenClass = '\003; -- ControlC
State:
TYPE = [0..17];
0:
1: id
2: id ←
3: [ ?{id : id},
4: [ ?{id : id}, id
5: [ ?{id : id}, id :
6: [ ?{id : id}, id : id
7: [ ?{id : id}, ]
8: [ ?{id : id}, ] ←
9: LHS ← id
10: ?(LHS ←) id [ ?{id : id},
11: ?(LHS ←) id [ ?{id : id}, id
12: ?(LHS ←) id [ ?{id : id}, id :
13: ?(LHS ←) id [ ?{id : id}, id : id
14: ?(LHS ←) id [ ?{id : id}, ]
15: ?(LHS) id ?([ ?{id : id}, ])) -
16: ?(?(LHS) id ?([ ?{id : id}, ])) - id
17: ?(?(LHS) id ?([ ?{id : id}, ])) ?(- ?id) (;|eom) | eom
where LHS = id | [ ?{id : id}, ]
Failed: PUBLIC ERROR = CODE;
external parsing routine
ParseCommand:
PUBLIC
PROC [s:
IO.
STREAM]
RETURNS [operator:
ROPE, argList, resultList: PairList, switches:
ROPE] = {
token: TokenClass ¬ 0C;
idString: ROPE;
tIndex: CARDINAL;
c: CHAR ¬ ' ;
NextToken:
PROC =
INLINE {
WHILE c = '
OR c = '\012
OR c = '\015
DO c ¬ IO.GetChar[s ! IO.EndOfStream => {c ¬ eom; CONTINUE}] ENDLOOP;
tIndex ¬ IO.GetIndex[s] - 1;
SELECT c
FROM
IN ['a..'z],
IN ['A..'Z],
IN ['0..'9], '<, '., '+, '~, '!, '$ => {
idString ¬ NIL;
DO
SELECT c
FROM
IN ['a..'z], IN ['A..'Z], IN ['0..'9],
'<, '>, '., '+, '~, '!, '$ => {
idString ¬ Rope.Concat[idString, Rope.FromChar[c]];
c ¬ IO.GetChar[s ! IO.EndOfStream => {c ¬ eom; CONTINUE}]};
ENDCASE => EXIT;
ENDLOOP;
token ¬ id};
'←, '¬, '[, '], ':, '- =>
{token ¬ c; c ¬ IO.GetChar[s ! IO.EndOfStream => {c ¬ eom; CONTINUE}]};
',, ';, eom => token ¬ c;
ENDCASE => BadCommand[]};
pair: ARRAY [0..1] OF ROPE;
PushArg: PROC = INLINE {argList ¬ CONS[[pair[0], pair[1]], argList]};
PushResult: PROC = INLINE {resultList ¬ CONS[[pair[0], pair[1]], resultList]};
RestoreToken: PROC = {IO.SetIndex[s, tIndex]};
BadCommand:
PROC = {
ERROR Failed};
state: State ¬ 0;
operator ¬ switches ¬ NIL; argList ¬ resultList ¬ NIL;
UNTIL state = 17
DO
NextToken[];
SELECT token
FROM
id =>
SELECT state
FROM
0 => {operator ¬ idString; state ¬ 1};
2, 8 => {operator ¬ idString; state ¬ 9};
3 => {pair[0] ¬ idString; state ¬ 4};
5 => {pair[1] ¬ idString; PushResult[]; state ¬ 6};
10 => {pair[0] ¬ idString; state ¬ 11};
12 => {pair[1] ¬ idString; PushArg[]; state ¬ 13};
15 => {switches ¬ switches.Concat[idString]; state ¬ 16};
1, 9, 14, 16 => {RestoreToken[]; state ¬ 17};
ENDCASE => BadCommand[];
'←, '¬ =>
SELECT state
FROM
1 => {
pair[0] ¬ NIL; pair[1] ¬ operator; operator ¬ NIL;
PushResult[]; state ¬ 2};
7 => state ¬ 8;
ENDCASE => BadCommand[];
'[ =>
SELECT state
FROM
0 => state ¬ 3;
1, 9 => state ¬ 10;
14 => {RestoreToken[]; state ¬ 17};
ENDCASE => BadCommand[];
'] =>
SELECT state
FROM
3, 6 => state ¬ 7;
10, 13 => state ¬ 14;
ENDCASE => BadCommand[];
': =>
SELECT state
FROM
4 => state ¬ 5;
11 => state ¬ 12;
ENDCASE => BadCommand[];
', =>
SELECT state
FROM
6 => {state ¬ 3; c ¬ IO.GetChar[s ! IO.EndOfStream => {c ¬ eom; CONTINUE}]};
13 => {state ¬ 10; c ¬ IO.GetChar[s ! IO.EndOfStream => {c ¬ eom; CONTINUE}]};
1, 9, 14, 15, 16 => state ¬ 17;
ENDCASE => BadCommand[];
'- =>
SELECT state
FROM
0, 1, 9, 14, 16 => state ¬ 15;
ENDCASE => BadCommand[];
'; =>
SELECT state
FROM
1, 9, 14, 15, 16 => state ¬ 17;
ENDCASE => BadCommand[];
eom =>
SELECT state
FROM
0, 1, 9, 14, 15, 16 => state ¬ 17;
ENDCASE => BadCommand[];
ENDCASE;
ENDLOOP;
RETURN};
Echo:
PUBLIC
PROC [
d: IO.STREAM,
operator: ROPE, argList, resultList: PairList, switches: ROPE] = {
PutList:
PROC [list: PairList] = {
d.PutChar['[];
FOR p: PairList ¬ list, p.rest
UNTIL p =
NIL
DO
IF p.first.key # NIL THEN {IO.PutRope[d, p.first.key]; IO.PutRope[d, ": "]};
IO.PutRope[d, p.first.val];
IF p.rest # NIL THEN IO.PutRope[d, ", "];
ENDLOOP;
d.PutChar[']]};
IF resultList #
NIL
THEN {
IF resultList.rest =
NIL
AND resultList.first.key =
NIL
THEN IO.PutRope[d, resultList.first.val]
ELSE PutList[resultList];
IO.PutRope[d, " ¬ "]};
IO.PutRope[d, operator];
IF argList # NIL THEN PutList[argList];
IF switches #
NIL
AND switches.Length[] > 0
THEN {
d.PutChar['-]; IO.PutRope[d, switches]}};
GetSwitches:
PUBLIC
PROC [switches:
ROPE, default: NPGSCommandUtil.Switches]
RETURNS[NPGSCommandUtil.Switches] = {
sense: BOOL ¬ TRUE;
length: INT ¬ switches.Length[];
FOR i:
INT
IN [0..length)
DO
c: CHAR = switches.Fetch[i];
SELECT Ascii.Lower[c]
FROM
'~ => sense ¬ ~sense;
IN ['a..'z] => {default[c] ¬ sense; sense ¬ TRUE};
ENDCASE;
ENDLOOP;
RETURN[default]};
PairList utilities
GetNthPair:
PUBLIC
PROC [list: PairList, n:
CARDINAL, delete:
BOOL¬
FALSE]
RETURNS [key, value: ROPE¬NIL] = {
i: CARDINAL ¬ 0;
FOR p: PairList ¬ list, p.rest
UNTIL p =
NIL
DO
IF i = n
THEN {key ¬ p.first.key; value ¬ p.first.val;
IF delete THEN p.first.key ¬ p.first.val ¬ NIL; EXIT};
i ¬ i+1;
ENDLOOP;
RETURN};
ListLength:
PUBLIC
PROC [list: PairList]
RETURNS [n:
CARDINAL¬0] = {
FOR p: PairList ¬ list, p.rest UNTIL p = NIL DO n ¬ n+1 ENDLOOP;
RETURN};
KeyValue:
PUBLIC
PROC [key:
ROPE, list: PairList, delete:
BOOL¬
FALSE]
RETURNS [s: ROPE¬NIL] = {
FOR p: PairList ¬ list, p.rest
UNTIL p =
NIL
DO
IF Rope.Equal[p.first.key, key,
FALSE]
THEN {
s ¬ p.first.val; IF delete THEN p.first.val ¬ NIL; EXIT};
ENDLOOP;
RETURN};
file naming utilities
SetExtension:
PUBLIC
PROC [root, defaultExt:
ROPE]
RETURNS [name:
ROPE] = {
IF Rope.Find[root, "."] < 0 THEN root ¬ Rope.Cat[root, ".", defaultExt];
RETURN[root]};
GetRootName:
PUBLIC
PROC [name:
ROPE]
RETURNS [root:
ROPE] = {
dotIndex: INT ¬ Rope.Find[name, "."];
RETURN[IF dotIndex < 0 THEN name ELSE Rope.Substr[name, 0, dotIndex]]};
}.