Tcl Source Code

Check-in [699e9fd1dd]
Login
Bounty program for improvements to Tcl and certain Tcl packages.

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Merge 8.7
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 699e9fd1dd05796922293dc16cd62806c5a4c1862fc891fbf656833918b274f3
User & Date: jan.nijtmans 2019-06-11 15:32:49
Context
2019-06-12
15:42
Merge 8.7 check-in: c5ff3f41bd user: jan.nijtmans tags: trunk
2019-06-11
15:32
Merge 8.7 check-in: 699e9fd1dd user: jan.nijtmans tags: trunk
15:32
Merge 8.6 check-in: 688dee2254 user: jan.nijtmans tags: core-8-branch
2019-06-10
19:24
merge 8.7 check-in: f8d415a72b user: dgp tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to doc/expr.n.

91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
...
186
187
188
189
190
191
192


193
194
195
196
197
198
199
...
204
205
206
207
208
209
210

211
212
213
214
215
216
217
...
335
336
337
338
339
340
341
342



343

344
345
346
347
348
349
350
\fBTcl\fR.
.PP
Below are some examples of simple expressions where the value of \fBa\fR is 3
and the value of \fBb\fR is 6.  The command on the left side of each line
produces the value on the right side.
.PP
.CS
.ta 8c
\fBexpr\fR 3.1 + $a	\fI6.1\fR
\fBexpr\fR 2 + "$a.$b"	\fI5.6\fR
\fBexpr\fR 4*[llength "6 2"]	\fI8\fR
\fBexpr\fR {{word one} < "word $a"}	\fI0\fR
.CE
.SS OPERATORS
.PP
................................................................................
Bit-wise OR.  Valid for integer operands.
.TP 20
\fB&&\fR
.
Logical AND.  If both operands are true, the result is 1, or 0 otherwise.
This operator evaluates lazily; it only evaluates its second operand if it
must in order to determine its result.


.TP 20
\fB||\fR
.
Logical OR.  If both operands are false, the result is 0, or 1 otherwise.
This operator evaluates lazily; it only evaluates its second operand if it
must in order to determine its result.
.TP 20
................................................................................
This operator evaluates lazily; it evaluates only one of \fIy\fR or \fIz\fR.
.PP
The exponentiation operator promotes types in the same way that the multiply
and divide operators do, and the result is is the same as the result of
\fBpow\fR.
Exponentiation groups right-to-left within a precedence level. Other binary
operators group left-to-right.  For example, the value of

.PP
.CS
\fBexpr\fR {4*2 < 7}
.CE
.PP
is 0, while the value of
.PP
................................................................................
substitutions on, enclosing an expression in braces or otherwise quoting it
so that it's a static value allows the Tcl compiler to generate bytecode for
the expression, resulting in better speed and smaller storage requirements.
This also avoids issues that can arise if Tcl is allowed to perform
substitution on the value before \fBexpr\fR is called.
.PP
In the following example, the value of the expression is 11 because the Tcl parser first
substitutes \fB$b\fR and \fBexpr\fR then substitutes \fB$a\fR.  Enclosing the



expression in braces would result in a syntax error.

.PP
.CS
set a 3
set b {$a + 2}
\fBexpr\fR $b*4
.CE
.PP






|







 







>
>







 







>







 







|
>
>
>
|
>







91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
...
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
...
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
...
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
\fBTcl\fR.
.PP
Below are some examples of simple expressions where the value of \fBa\fR is 3
and the value of \fBb\fR is 6.  The command on the left side of each line
produces the value on the right side.
.PP
.CS
.ta 9c
\fBexpr\fR 3.1 + $a	\fI6.1\fR
\fBexpr\fR 2 + "$a.$b"	\fI5.6\fR
\fBexpr\fR 4*[llength "6 2"]	\fI8\fR
\fBexpr\fR {{word one} < "word $a"}	\fI0\fR
.CE
.SS OPERATORS
.PP
................................................................................
Bit-wise OR.  Valid for integer operands.
.TP 20
\fB&&\fR
.
Logical AND.  If both operands are true, the result is 1, or 0 otherwise.
This operator evaluates lazily; it only evaluates its second operand if it
must in order to determine its result.
This operator evaluates lazily; it only evaluates its second operand if it
must in order to determine its result.
.TP 20
\fB||\fR
.
Logical OR.  If both operands are false, the result is 0, or 1 otherwise.
This operator evaluates lazily; it only evaluates its second operand if it
must in order to determine its result.
.TP 20
................................................................................
This operator evaluates lazily; it evaluates only one of \fIy\fR or \fIz\fR.
.PP
The exponentiation operator promotes types in the same way that the multiply
and divide operators do, and the result is is the same as the result of
\fBpow\fR.
Exponentiation groups right-to-left within a precedence level. Other binary
operators group left-to-right.  For example, the value of
.PP
.PP
.CS
\fBexpr\fR {4*2 < 7}
.CE
.PP
is 0, while the value of
.PP
................................................................................
substitutions on, enclosing an expression in braces or otherwise quoting it
so that it's a static value allows the Tcl compiler to generate bytecode for
the expression, resulting in better speed and smaller storage requirements.
This also avoids issues that can arise if Tcl is allowed to perform
substitution on the value before \fBexpr\fR is called.
.PP
In the following example, the value of the expression is 11 because the Tcl parser first
substitutes \fB$b\fR and \fBexpr\fR then substitutes \fB$a\fR as part
of evaluating the expression
.QW "$a + 2*4" .
Enclosing the
expression in braces would result in a syntax error as \fB$b\fR does
not evaluate to a numeric value.
.PP
.CS
set a 3
set b {$a + 2}
\fBexpr\fR $b*4
.CE
.PP

Changes to generic/tclInt.h.

60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
#endif
#ifdef NO_STRING_H
#include "../compat/string.h"
#else
#include <string.h>
#endif
#if defined(STDC_HEADERS) || defined(__STDC__) || defined(__C99__FUNC__) \
     || defined(__cplusplus) || defined(_MSC_VER)
#include <stddef.h>
#else
typedef int ptrdiff_t;
#endif

/*
 * Ensure WORDS_BIGENDIAN is defined correctly:






|







60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
#endif
#ifdef NO_STRING_H
#include "../compat/string.h"
#else
#include <string.h>
#endif
#if defined(STDC_HEADERS) || defined(__STDC__) || defined(__C99__FUNC__) \
     || defined(__cplusplus) || defined(_MSC_VER) || defined(__ICC)
#include <stddef.h>
#else
typedef int ptrdiff_t;
#endif

/*
 * Ensure WORDS_BIGENDIAN is defined correctly: