"
COPYRIGHT (c) 1988 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
"{ Package: 'stx:libbasic' }"
PositionableStream subclass:#ReadStream
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'Streams'
!
!ReadStream class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1988 by Claus Gittinger
All Rights Reserved
This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice. This software may not
be provided or otherwise made available to, or used by, any
other person. No title to or ownership of the software is
hereby transferred.
"
!
documentation
"
ReadStream defines protocol for reading streamwise over collections.
[author:]
Claus Gittinger
"
! !
!ReadStream methodsFor:'converting'!
readStream
"return a readStream from the receiver. Since this is already
a readStream, return self."
^ self
! !
!ReadStream methodsFor:'emphasis'!
emphasis
"return the emphasis of the current (i.e. next returned by #next)
element. Streams on a string will return nil for all elements.
Streams on collections which nothing at all about emphasises,
will report an error."
^ collection emphasisAt:position.
"
|t s|
t := 'hello world' asText
emphasizeFrom:1 to:5 with:#bold;
emphasizeFrom:7 to:11 with:#italic.
s := t readStream.
[s atEnd] whileFalse:[
Transcript show:(s emphasis); show:' '.
Transcript show:''''; show:(s next); showCR:''''.
].
"
"Modified: 15.5.1996 / 17:30:33 / cg"
! !
!ReadStream methodsFor:'misc'!
readWait
^ self "/ never have to wait
!
readWaitWithTimeoutMs:millis
^ false "/ never have to wait
! !
!ReadStream methodsFor:'queries'!
copyFrom:beginning to:end
^ collection copyFrom:beginning to:end
!
isReadable
"return true, if reading is supported by the recevier.
Here, true is always returned."
^ true
"Modified: 4.10.1997 / 17:59:21 / cg"
!
isWritable
"return true, if writing is supported by the recevier.
This has to be redefined in concrete subclasses."
^ false
!
size
"return the number of elements in the streamed collection."
^ collection size
"Created: 13.9.1996 / 18:14:35 / cg"
"Modified: 4.10.1997 / 17:59:45 / cg"
! !
!ReadStream methodsFor:'reading'!
next
"return the next element; advance read pointer.
return nil, if there is no next element.
- tuned for a bit more speed on String/ByteArray/Array-Streams"
|ret|
%{ /* NOCONTEXT */
REGISTER int pos;
unsigned ch;
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isNonNilObject(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
if (pos > 0 && pos <= __intVal(l)) {
OBJ cls;
cls = __qClass(coll);
if (cls == @global(String)) {
if (pos <= __stringSize(coll)) {
__INST(position) = __MKSMALLINT(pos + 1);
ch = __stringVal(coll)[pos-1];
RETURN ( __MKCHARACTER(ch) );
}
} else if (cls == @global(ByteArray)) {
if (pos <= __byteArraySize(coll)) {
__INST(position) = __MKSMALLINT(pos + 1);
ch = __ByteArrayInstPtr(coll)->ba_element[pos-1];
RETURN ( __MKSMALLINT(ch) );
}
} else if (cls == @global(Array)) {
if (pos <= __arraySize(coll)) {
__INST(position) = __MKSMALLINT(pos + 1);
RETURN ( __ArrayInstPtr(coll)->a_element[pos-1]);
}
}
}
}
%}
.
(position > readLimit) ifTrue:[^ self pastEnd].
ret := collection at:position.
position := position + 1.
^ ret
!
nextAlphaNumericWord
"read the next word (i.e. up to non letter-or-digit).
return a string containing those characters.
Skips any non-alphanumeric chars first.
- tuned for speed on String-Streams for faster scanning"
%{
/* speedup, if collection is a string */
int pos, limit, sz;
int len;
char buffer[256];
REGISTER unsigned char *cp;
REGISTER unsigned ch;
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
limit = __intVal(l);
sz = __qSize(coll) - OHDR_SIZE;
if (sz < limit)
limit = sz;
cp = __stringVal(coll) + pos - 1;
for (;;) {
if (pos > limit) break;
ch = *cp;
if (((ch >= 'a') && (ch <= 'z')) ||
((ch >= 'A') && (ch <= 'Z')) ||
((ch >= '0') && (ch <= '9')))
break;
cp++;
pos++;
}
len = 0;
for (;;) {
if (pos > limit) break;
ch = *cp & 0xFF;
if (! (((ch >= 'a') && (ch <= 'z')) ||
((ch >= 'A') && (ch <= 'Z')) ||
((ch >= '0') && (ch <= '9'))))
break;
buffer[len++] = ch;
if (len >= (sizeof(buffer)-1)) {
/* emergency */
break;
}
pos++;
cp++;
}
__INST(position) = __MKSMALLINT(pos);
buffer[len] = '\0';
RETURN ( (len != 0) ? __MKSTRING_L(buffer, len) : nil );
}
%}
.
^ super nextAlphaNumericWord
!
nextByte
"return the next element; advance read pointer.
return nil, if there is no next element.
- tuned for a bit more speed on String/ByteArray/Array-Streams"
|ret|
%{ /* NOCONTEXT */
REGISTER int pos;
unsigned ch;
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isNonNilObject(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
if (pos > 0 && pos <= __intVal(l)) {
OBJ cls;
cls = __qClass(coll);
if (cls == @global(String)) {
if (pos <= __stringSize(coll)) {
__INST(position) = __MKSMALLINT(pos + 1);
ch = __stringVal(coll)[pos-1];
RETURN ( __MKSMALLINT(ch) );
}
} else if (cls == @global(ByteArray)) {
if (pos <= __byteArraySize(coll)) {
__INST(position) = __MKSMALLINT(pos + 1);
ch = __ByteArrayInstPtr(coll)->ba_element[pos-1];
RETURN ( __MKSMALLINT(ch) );
}
} else if (cls == @global(Array)) {
if (pos <= __arraySize(coll)) {
__INST(position) = __MKSMALLINT(pos + 1);
RETURN ( __ArrayInstPtr(coll)->a_element[pos-1]);
}
}
}
}
%}
.
(position > readLimit) ifTrue:[^ self pastEnd].
ret := collection at:position.
position := position + 1.
^ ret
!
nextDecimalInteger
"read the next integer in radix 10. dont skip whitespace.
- tuned for speed on String-Streams for faster scanning"
|value nextOne|
%{
int pos, limit, sz;
REGISTER unsigned char *cp;
REGISTER unsigned ch;
int val = 0;
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
limit = __intVal(l);
sz = __qSize(coll) - OHDR_SIZE;
if (sz < limit)
limit = sz;
cp = __stringVal(coll) + pos - 1;
for (;;) {
if (pos > limit) break;
ch = *cp;
if ((ch < '0') || (ch > '9')) break;
val = val * 10 + (ch - '0');
pos++;
if (val > (_MAX_INT / 10)) goto oops;
cp++;
}
__INST(position) = __MKSMALLINT(pos);
RETURN (__MKSMALLINT(val));
}
oops:
value = __MKSMALLINT(val);
%}
.
"fall-back for non-string streams - we have to continue where
above primitive left off, in case of a large integer ...
(instead of doing a super nextDecimalInteger)"
nextOne := self peek.
[nextOne notNil and:[nextOne isDigitRadix:10]] whileTrue:[
value = (value * 10) + nextOne digitValue.
nextOne := self nextPeek
].
^ value
!
nextPeek
"advance read pointer return the peek element.
this is equivalent to (self next; peek).
- tuned for speed on String-Streams for faster scanning"
%{ /* NOCONTEXT */
OBJ coll, l, p;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll) && __bothSmallInteger(p, l)) {
REGISTER int pos;
unsigned ch;
pos = __intVal(p);
if ((pos > 0) && (pos < __intVal(l)) && (pos < __stringSize(coll))) {
pos += 1;
__INST(position) = __MKSMALLINT(pos);
ch = __stringVal(coll)[pos-1];
RETURN ( __MKCHARACTER(ch) );
}
}
%}
.
(position > readLimit) ifTrue:[^ self pastEnd].
position := position + 1.
(position > readLimit) ifTrue:[^ self pastEnd].
^ collection at:position
!
nextSymbol
"read the next selector-symbol (i.e. up to non letter-or-digit).
return a string containing those characters.
- tuned for speed on String-Streams for faster scanning"
%{
int pos, limit, sz;
int len;
char buffer[256];
REGISTER unsigned char *cp;
REGISTER unsigned ch;
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
limit = __intVal(l);
sz = __qSize(coll) - OHDR_SIZE;
if (sz < limit)
limit = sz;
cp = __stringVal(coll) + pos - 1;
len = 0;
for (;;) {
if (pos > limit) break;
ch = *cp;
if (! (((ch >= 'a') && (ch <= 'z')) ||
((ch >= 'A') && (ch <= 'Z')) ||
((ch >= '0') && (ch <= '9')) ||
(ch == ':')))
break;
buffer[len++] = ch;
if (len >= (sizeof(buffer)-1)) {
/* emergency */
break;
}
pos++;
cp++;
}
__INST(position) = __MKSMALLINT(pos);
buffer[len] = '\0';
RETURN ( (len != 0) ? __MKSTRING_L(buffer, len) : nil );
}
%}
.
^ super nextSymbol
!
peek
"return the next element; do NOT advance read pointer.
return nil, if there is no next element.
- tuned for a bit more speed on String/ByteArray/Array-Streams"
%{ /* NOCONTEXT */
REGISTER int pos;
unsigned ch;
OBJ coll;
OBJ cls, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isNonNilObject(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
if (pos <= __intVal(l) && pos > 0) {
cls = __qClass(coll);
if (cls == @global(String)) {
if (pos <= __stringSize(coll)) {
ch = __stringVal(coll)[pos-1];
RETURN ( __MKCHARACTER(ch) );
}
} else if (cls == @global(ByteArray)) {
if (pos <= __byteArraySize(coll)) {
ch = __ByteArrayInstPtr(coll)->ba_element[pos-1];
RETURN ( __MKSMALLINT(ch) );
}
} else if (cls == @global(Array)) {
if (pos <= __arraySize(coll)) {
RETURN ( __ArrayInstPtr(coll)->a_element[pos-1]);
}
}
}
}
%}
.
(position > readLimit) ifTrue:[^ self pastEnd].
^ collection at:position
!
peekOrNil
"return the next element; do NOT advance read pointer.
return nil, if there is no next element.
This is much like #peek -
However, unlike #peek, this does not raise an atEnd-query signal - even
if handled. Instead, nil is returned immediately."
%{ /* NOCONTEXT */
REGISTER int pos;
unsigned ch;
OBJ coll;
OBJ cls, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isNonNilObject(coll) && __bothSmallInteger(p, l)) {
pos = __intVal(p);
if (pos <= __intVal(l) && pos > 0) {
cls = __qClass(coll);
if (cls == @global(String)) {
if (pos <= __stringSize(coll)) {
ch = __stringVal(coll)[pos-1];
RETURN ( __MKCHARACTER(ch) );
}
RETURN ( nil );
} else if (cls == @global(ByteArray)) {
if (pos <= __byteArraySize(coll)) {
ch = __ByteArrayInstPtr(coll)->ba_element[pos-1];
RETURN ( __MKSMALLINT(ch) );
}
RETURN ( nil );
} else if (cls == @global(Array)) {
if (pos <= __arraySize(coll)) {
RETURN ( __ArrayInstPtr(coll)->a_element[pos-1]);
}
RETURN ( nil );
}
}
}
%}
.
(position > readLimit) ifTrue:[^ nil].
^ collection at:position
!
skipSeparators
"skip all whitespace; next will return next non-white-space element.
Return the peeked character or nil, if the end-of-stream was reached.
- reimplemented for speed on String-Streams for faster scanning"
%{ /* NOCONTEXT */
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll) && __bothSmallInteger(p, l)) {
REGISTER unsigned char *chars;
REGISTER unsigned ch;
REGISTER int pos;
int limit;
int sz;
pos = __intVal(p);
if (pos <= 0) {
RETURN ( nil );
}
limit = __intVal(l);
sz = __qSize(coll) - OHDR_SIZE;
if (limit > sz) {
limit = sz;
}
chars = (unsigned char *)(__stringVal(coll) + pos - 1);
while (pos <= limit) {
pos++;
ch = *chars++;
if ((ch > 0x20)
|| ((ch != ' ')
&& (ch != '\t')
&& (ch != '\r')
&& (ch != '\n')
&& (ch != '\f')
&& (ch != 0x0B))) {
__INST(position) = __MKSMALLINT(pos-1);
RETURN ( __MKCHARACTER(ch) );
}
}
__INST(position) = __MKSMALLINT(pos);
RETURN ( nil );
}
%}.
^ super skipSeparators
"
|s|
s := ' hello world ' readStream.
s skipSeparators.
s next.
"
!
skipSeparatorsExceptCR
"skip all whitespace except newlines;
next will return next non-white-space element.
- reimplemented for speed on String-Streams for faster scanning"
%{ /* NOCONTEXT */
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll) && __bothSmallInteger(p, l)) {
REGISTER unsigned char *chars;
REGISTER unsigned ch;
REGISTER int pos;
int limit;
pos = __intVal(p);
if (pos <= 0) {
RETURN ( nil );
}
limit = __intVal(l);
if (limit > (__qSize(coll) - OHDR_SIZE))
limit = __qSize(coll) - OHDR_SIZE;
chars = (unsigned char *)(__stringVal(coll) + pos - 1);
while (pos <= limit) {
ch = *chars++;
if (((int)ch > 0x20)
|| (
(ch != ' ')
&& (ch != '\t')
&& (ch != '\f')
&& (ch != '\b')
&& (ch != 0x0B))) {
__INST(position) = __MKSMALLINT(pos);
RETURN ( __MKCHARACTER(ch) );
}
pos++;
}
__INST(position) = __MKSMALLINT(pos);
RETURN ( nil );
}
%}
.
^ super skipSeparatorsExceptCR
!
skipThrough:anObject
"skip all objects up-to and including anObject.
Return the receiver if skip was successful,
otherwise (i.e. if not found) return nil and leave the stream positioned at the end.
On success, the next read operation will return the element after anObject.
- reimplemented for speed on String-Streams for faster scanning"
%{ /* NOCONTEXT */
OBJ coll, p, l;
coll = __INST(collection);
p = __INST(position);
l = __INST(readLimit);
if (__isString(coll)
&& __isCharacter(anObject)
&& __bothSmallInteger(p, l)) {
REGISTER unsigned char *chars;
REGISTER int pos, limit;
unsigned ch;
int sz;
pos = __intVal(p);
if (pos <= 0) {
RETURN ( nil );
}
limit = __intVal(l);
sz = __stringSize(coll);
if (limit > sz) limit = sz;
chars = (unsigned char *)(__stringVal(coll) + pos - 1);
ch = __intVal(_characterVal(anObject)) & 0xFF;
while (pos < limit) {
if (*chars == ch) {
ch = *++chars;
pos++;
__INST(position) = __MKSMALLINT(pos);
RETURN ( self );
}
chars++;
pos++;
}
__INST(position) = __MKSMALLINT(pos+1);
RETURN ( nil );
}
%}.
^ super skipThrough:anObject
! !
!ReadStream methodsFor:'writing'!
nextPut:anElement
"catch write access to readstreams - report an error"
self shouldNotImplement
! !
!ReadStream class methodsFor:'documentation'!
version
^ '$Header: /cvs/stx/stx/libbasic/ReadStream.st,v 1.45 2002-10-29 10:55:29 james Exp $'
! !