Tcl Source Code

non-numeric operands, string comparisons, and some
additional operators not found in C.
.PP
When an expression evaluates to an integer, the value is the decimal form of
the integer, and when an expression evaluates to a floating-point number, the
value is the form produced by the \fB%g\fR format specifier of Tcl's
\fBformat\fR command.






.SS OPERANDS
.PP
An expression consists of a combination of operands, operators, parentheses and
commas, possibly with whitespace between any of these elements, which is
ignored.
.PP
An operand may be specified in any of the following ways:
................................................................................
.CE
.PP
Set a variable indicating whether an environment variable is defined and has
value of true:
.PP
.CS
set isTrue [\fBexpr\fR {

    [info exists ::env(SOME_ENV_VAR)] &&

    [string is true -strict $::env(SOME_ENV_VAR)]
}]
.CE
.PP
Generate a random integer in the range 0..99 inclusive:
.PP
.CS

non-numeric operands, string comparisons, and some
additional operators not found in C.
.PP
When an expression evaluates to an integer, the value is the decimal form of
the integer, and when an expression evaluates to a floating-point number, the
value is the form produced by the \fB%g\fR format specifier of Tcl's
\fBformat\fR command.
.PP
.VS "TIP 582"
You can use \fB#\fR at any point in the expression (except inside double
quotes or braces) to start a comment. Comments last to the end of the line or
the end of the expression, whichever comes first.
.VE "TIP 582"
.SS OPERANDS
.PP
An expression consists of a combination of operands, operators, parentheses and
commas, possibly with whitespace between any of these elements, which is
ignored.
.PP
An operand may be specified in any of the following ways:
................................................................................
.CE
.PP
Set a variable indicating whether an environment variable is defined and has
value of true:
.PP
.CS
set isTrue [\fBexpr\fR {
    # Does the environment variable exist, and...
    [info exists ::env(SOME_ENV_VAR)] &&
    # ...does it contain a proper true value?
    [string is true -strict $::env(SOME_ENV_VAR)]
}]
.CE
.PP
Generate a random integer in the range 0..99 inclusive:
.PP
.CS

#define BAREWORD	3	/* Ambigous. Resolves to BOOLEAN or to
				 * FUNCTION or a parse error according to
				 * context and value. */
#define INCOMPLETE	4	/* A parse error. Used only when the single
				 * "=" is encountered.  */
#define INVALID		5	/* A parse error. Used when any punctuation
				 * appears that's not a supported operator. */



/* Leaf lexemes */

#define NUMBER		(LEAF | 1)
				/* For literal numbers */
#define SCRIPT		(LEAF | 2)
				/* Script substitution; [foo] */
................................................................................
	INVALID		/* DC4 */,	INVALID		/* NAK */,
	INVALID		/* SYN */,	INVALID		/* ETB */,
	INVALID		/* CAN */,	INVALID		/* EM */,
	INVALID		/* SUB */,	INVALID		/* ESC */,
	INVALID		/* FS */,	INVALID		/* GS */,
	INVALID		/* RS */,	INVALID		/* US */,
	INVALID		/* SPACE */,	0		/* ! or != */,
	QUOTED		/* " */,	INVALID		/* # */,
	VARIABLE	/* $ */,	MOD		/* % */,
	0		/* & or && */,	INVALID		/* ' */,
	OPEN_PAREN	/* ( */,	CLOSE_PAREN	/* ) */,
	0		/* * or ** */,	PLUS		/* + */,
	COMMA		/* , */,	MINUS		/* - */,
	0		/* . */,	DIVIDE		/* / */,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			/* 0-9 */
................................................................................
	 */

	if (nodesUsed >= nodesAvailable) {
	    unsigned int size = nodesUsed * 2;
	    OpNode *newPtr = NULL;

	    do {
	      if (size <= UINT_MAX/sizeof(OpNode)) {

		newPtr = (OpNode *)attemptckrealloc(nodes, size * sizeof(OpNode));
	      }
	    } while ((newPtr == NULL)
		    && ((size -= (size - nodesUsed) / 2) > nodesUsed));
	    if (newPtr == NULL) {
		TclNewLiteralStringObj(msg,
			"not enough memory to parse expression");
		errCode = "NOMEM";
		goto error;
................................................................................
	 * Use context to categorize the lexemes that are ambiguous.
	 */

	if ((NODE_TYPE & lexeme) == 0) {
	    int b;

	    switch (lexeme) {




	    case INVALID:
		msg = Tcl_ObjPrintf("invalid character \"%.*s\"",
			scanned, start);
		errCode = "BADCHAR";
		goto error;
	    case INCOMPLETE:
		msg = Tcl_ObjPrintf("incomplete operator \"%.*s\"",
................................................................................
		     * names we've parsed in the order we found them.
		     */

		    Tcl_ListObjAppendElement(NULL, funcList, literal);
		} else if (Tcl_GetBooleanFromObj(NULL,literal,&b) == TCL_OK) {
		    lexeme = BOOLEAN;
		} else {


























		    Tcl_DecrRefCount(literal);
		    msg = Tcl_ObjPrintf("invalid bareword \"%.*s%s\"",
			    (scanned < limit) ? scanned : limit - 3, start,
			    (scanned < limit) ? "" : "...");
		    post = Tcl_ObjPrintf(
			    "should be \"$%.*s%s\" or \"{%.*s%s}\"",
			    (scanned < limit) ? scanned : limit - 3,
................................................................................
    int numBytes,		/* Number of bytes in string. */
    unsigned char *lexemePtr,	/* Write code of parsed lexeme to this
				 * storage. */
    Tcl_Obj **literalPtr)	/* Write corresponding literal value to this
				   storage, if non-NULL. */
{
    const char *end;
    int scanned;
    Tcl_UniChar ch = 0;
    Tcl_Obj *literal = NULL;
    unsigned char byte;

    if (numBytes == 0) {
	*lexemePtr = END;
	return 0;
................................................................................
    }
    byte = UCHAR(*start);
    if (byte < sizeof(Lexeme) && Lexeme[byte] != 0) {
	*lexemePtr = Lexeme[byte];
	return 1;
    }
    switch (byte) {










    case '*':
	if ((numBytes > 1) && (start[1] == '*')) {
	    *lexemePtr = EXPON;
	    return 2;
	}
	*lexemePtr = MULT;
	return 1;

#define BAREWORD	3	/* Ambigous. Resolves to BOOLEAN or to
				 * FUNCTION or a parse error according to
				 * context and value. */
#define INCOMPLETE	4	/* A parse error. Used only when the single
				 * "=" is encountered.  */
#define INVALID		5	/* A parse error. Used when any punctuation
				 * appears that's not a supported operator. */
#define COMMENT		6	/* Comment. Lasts to end of line or end of
				 * expression, whichever comes first. */

/* Leaf lexemes */

#define NUMBER		(LEAF | 1)
				/* For literal numbers */
#define SCRIPT		(LEAF | 2)
				/* Script substitution; [foo] */
................................................................................
	INVALID		/* DC4 */,	INVALID		/* NAK */,
	INVALID		/* SYN */,	INVALID		/* ETB */,
	INVALID		/* CAN */,	INVALID		/* EM */,
	INVALID		/* SUB */,	INVALID		/* ESC */,
	INVALID		/* FS */,	INVALID		/* GS */,
	INVALID		/* RS */,	INVALID		/* US */,
	INVALID		/* SPACE */,	0		/* ! or != */,
	QUOTED		/* " */,	0		/* # */,
	VARIABLE	/* $ */,	MOD		/* % */,
	0		/* & or && */,	INVALID		/* ' */,
	OPEN_PAREN	/* ( */,	CLOSE_PAREN	/* ) */,
	0		/* * or ** */,	PLUS		/* + */,
	COMMA		/* , */,	MINUS		/* - */,
	0		/* . */,	DIVIDE		/* / */,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			/* 0-9 */
................................................................................
	 */

	if (nodesUsed >= nodesAvailable) {
	    unsigned int size = nodesUsed * 2;
	    OpNode *newPtr = NULL;

	    do {
		if (size <= UINT_MAX/sizeof(OpNode)) {
		    newPtr = (OpNode *) attemptckrealloc(nodes,
			    size * sizeof(OpNode));
		}
	    } while ((newPtr == NULL)
		    && ((size -= (size - nodesUsed) / 2) > nodesUsed));
	    if (newPtr == NULL) {
		TclNewLiteralStringObj(msg,
			"not enough memory to parse expression");
		errCode = "NOMEM";
		goto error;
................................................................................
	 * Use context to categorize the lexemes that are ambiguous.
	 */

	if ((NODE_TYPE & lexeme) == 0) {
	    int b;

	    switch (lexeme) {
	    case COMMENT:
		start += scanned;
		numBytes -= scanned;
		continue;
	    case INVALID:
		msg = Tcl_ObjPrintf("invalid character \"%.*s\"",
			scanned, start);
		errCode = "BADCHAR";
		goto error;
	    case INCOMPLETE:
		msg = Tcl_ObjPrintf("incomplete operator \"%.*s\"",
................................................................................
		     * names we've parsed in the order we found them.
		     */

		    Tcl_ListObjAppendElement(NULL, funcList, literal);
		} else if (Tcl_GetBooleanFromObj(NULL,literal,&b) == TCL_OK) {
		    lexeme = BOOLEAN;
		} else {
		    /*
		     * Tricky case: see test expr-62.10
		     */

		    int scanned2 = scanned;
		    do {
			scanned2 += TclParseAllWhiteSpace(
				start + scanned2, numBytes - scanned2);
			scanned2 += ParseLexeme(
				start + scanned2, numBytes - scanned2, &lexeme,
				NULL);
		    } while (lexeme == COMMENT);
		    if (lexeme == OPEN_PAREN) {
			/*
			 * Actually a function call, but with obscuring
			 * comments.  Skip to the start of the parentheses.
			 * Note that we assume that open parentheses are one
			 * byte long.
			 */

			lexeme = FUNCTION;
			Tcl_ListObjAppendElement(NULL, funcList, literal);
			scanned = scanned2 - 1;
			break;
		    }

		    Tcl_DecrRefCount(literal);
		    msg = Tcl_ObjPrintf("invalid bareword \"%.*s%s\"",
			    (scanned < limit) ? scanned : limit - 3, start,
			    (scanned < limit) ? "" : "...");
		    post = Tcl_ObjPrintf(
			    "should be \"$%.*s%s\" or \"{%.*s%s}\"",
			    (scanned < limit) ? scanned : limit - 3,
................................................................................
    int numBytes,		/* Number of bytes in string. */
    unsigned char *lexemePtr,	/* Write code of parsed lexeme to this
				 * storage. */
    Tcl_Obj **literalPtr)	/* Write corresponding literal value to this
				   storage, if non-NULL. */
{
    const char *end;
    int scanned, size;
    Tcl_UniChar ch = 0;
    Tcl_Obj *literal = NULL;
    unsigned char byte;

    if (numBytes == 0) {
	*lexemePtr = END;
	return 0;
................................................................................
    }
    byte = UCHAR(*start);
    if (byte < sizeof(Lexeme) && Lexeme[byte] != 0) {
	*lexemePtr = Lexeme[byte];
	return 1;
    }
    switch (byte) {
    case '#':
	/*
	 * Scan forward over the comment contents.
	 */
	for (size = 0; byte != '\n' && byte != 0 && size < numBytes; size++) {
	    byte = UCHAR(start[size]);
	}
	*lexemePtr = COMMENT;
	return size - (byte == '\n');

    case '*':
	if ((numBytes > 1) && (start[1] == '*')) {
	    *lexemePtr = EXPON;
	    return 2;
	}
	*lexemePtr = MULT;
	return 1;

        set end [getbytes]
    }
    set leakedBytes [expr {$end - $tmp}]
} -cleanup {
    unset end i tmp
    rename getbytes {}
} -result 0
 



































# cleanup
catch {unset a}
catch {unset b}

::tcltest::cleanupTests
return

# Local Variables:
# mode: tcl
# fill-column: 78
# End:

        set end [getbytes]
    }
    set leakedBytes [expr {$end - $tmp}]
} -cleanup {
    unset end i tmp
    rename getbytes {}
} -result 0

proc extract {opcodes descriptor} {
    set instructions [dict values [dict get $descriptor instructions]]
    return [lmap i $instructions {
	if {[lindex $i 0] in $opcodes} {string cat $i} else continue
    }]
}

test compExpr-8.1 {TIP 582: expression comments} -setup {} -body {
    extract {loadStk add} [tcl::unsupported::getbytecode script {expr {
        $abc
	# + $def
	+ $ghi
    }}]
} -result {loadStk loadStk add}
test compExpr-8.2 {TIP 582: expression comments} -setup {} -body {
    extract {loadStk add} [tcl::unsupported::getbytecode script {expr {
        $abc
	# + $def
	# + $ghi }}]
} -result loadStk
test compExpr-8.3 {TIP 582: expression comments} -setup {} -body {
    extract {loadStk add} [tcl::unsupported::getbytecode script {expr {
        $abc
	# + $def\
	+ $ghi
    }}]
} -result loadStk
test compExpr-8.4 {TIP 582: expression comments} -setup {} -body {
    extract {loadStk add} [tcl::unsupported::getbytecode script {expr {
        $abc
	# + $def\\
	+ $ghi
    }}]
} -result {loadStk loadStk add}
 
# cleanup
catch {unset a}
catch {unset b}
catch {rename extract ""}
::tcltest::cleanupTests
return

# Local Variables:
# mode: tcl
# fill-column: 78
# End:

test expr-old-26.10a {error conditions} !ieeeFloatingPoint {
    list [catch {expr 2.0/0.0} msg] $msg $errorCode
} {1 {divide by zero} {ARITH DIVZERO {divide by zero}}}
test expr-old-26.10b {error conditions} ieeeFloatingPoint {
    list [catch {expr 2.0/0.0} msg] $msg
} {0 Inf}
test expr-old-26.11 {error conditions} -body {
    expr 2#
} -returnCodes error -match glob -result *
test expr-old-26.12 {error conditions} -body {
    expr a.b
} -returnCodes error -match glob -result *
test expr-old-26.13 {error conditions} {
    list [catch {expr {"a"/"b"}} msg] $msg
} {1 {can't use non-numeric string as operand of "/"}}

test expr-old-26.10a {error conditions} !ieeeFloatingPoint {
    list [catch {expr 2.0/0.0} msg] $msg $errorCode
} {1 {divide by zero} {ARITH DIVZERO {divide by zero}}}
test expr-old-26.10b {error conditions} ieeeFloatingPoint {
    list [catch {expr 2.0/0.0} msg] $msg
} {0 Inf}
test expr-old-26.11 {error conditions} -body {
    expr 2`
} -returnCodes error -match glob -result *
test expr-old-26.12 {error conditions} -body {
    expr a.b
} -returnCodes error -match glob -result *
test expr-old-26.13 {error conditions} {
    list [catch {expr {"a"/"b"}} msg] $msg
} {1 {can't use non-numeric string as operand of "/"}}

    foreach v2 $values r2 $results {
	test expr-61.[incr ctr] "float classification: isunordered($v1,$v2)" {
	    expr {isunordered($v1, $v2)}
	} [expr {$r1 || $r2}]
    }
}
unset -nocomplain values results ctr





























































 
# cleanup
unset -nocomplain a
unset -nocomplain min
unset -nocomplain max
::tcltest::cleanupTests
return

# Local Variables:
# mode: tcl
# End:

    foreach v2 $values r2 $results {
	test expr-61.[incr ctr] "float classification: isunordered($v1,$v2)" {
	    expr {isunordered($v1, $v2)}
	} [expr {$r1 || $r2}]
    }
}
unset -nocomplain values results ctr

test expr-62.1 {TIP 582: comments} -body {
    expr {1 # + 2}
} -result 1
test expr-62.2 {TIP 582: comments} -body {
    expr "1 #\n+ 2"
} -result 3
test expr-62.3 {TIP 582: comments} -setup {
    set ctr 0
} -body {
    expr {
	# This is a demonstration of a comment
	1 + 2 + 3
	# and another comment
	+ 4 + 5
	# + [incr ctr]
	+ [incr ctr]
    }
} -result 16
# Buggy because line breaks aren't tracked inside expressions at all
test expr-62.4 {TIP 582: comments don't hide line breaks} -setup {
    proc getline {} {
	dict get [info frame -1] line
    }
    set base [getline]
} -constraints knownBug -body {
    expr {
	0
	# a comment
	+ [getline] - $base
    }
} -cleanup {
    rename getline ""
} -result 5
test expr-62.5 {TIP 582: comments don't splice tokens} {
    set a False
    expr {$a#don't splice
ne#don't splice
false}
} 1
test expr-62.6 {TIP 582: comments don't splice tokens} {
    expr {0x2#don't splice
ne#don't splice
2}
} 1
test expr-62.7 {TIP 582: comments can go inside function calls} {
    expr {max(1,# comment
	      2)}
} 2
test expr-62.8 {TIP 582: comments can go inside function calls} {
    expr {max(1# comment
	      ,2)}
} 2
test expr-62.9 {TIP 582: comments can go inside function calls} {
    expr {max(# comment
	      1,2)}
} 2
test expr-62.10 {TIP 582: comments can go inside function calls} {
    expr {max# comment
	     (1,2)}
} 2
 
# cleanup
unset -nocomplain a
unset -nocomplain min
unset -nocomplain max
::tcltest::cleanupTests
return

# Local Variables:
# mode: tcl
# End:

} -returnCodes error -match glob -result {*invalid character*}
test parseExpr-22.20 {Bug d2ffcca163} -constraints testexprparser -body {
    testexprparser \u043f -1
} -returnCodes error -match glob -result {*invalid character*}
test parseExpr-22.21 {Bug d2ffcca163} -constraints testexprparser -body {
    testexprparser in\u0433(0) -1
} -returnCodes error -match glob -result {missing operand*}









# cleanup
cleanupTests
return

} -returnCodes error -match glob -result {*invalid character*}
test parseExpr-22.20 {Bug d2ffcca163} -constraints testexprparser -body {
    testexprparser \u043f -1
} -returnCodes error -match glob -result {*invalid character*}
test parseExpr-22.21 {Bug d2ffcca163} -constraints testexprparser -body {
    testexprparser in\u0433(0) -1
} -returnCodes error -match glob -result {missing operand*}

test parseExpr-23.1 {TIP 582: comments} -constraints testexprparser -body {
    testexprparser "7 # * 8 " -1
} -result {- {} 0 subexpr 7 1 text 7 0 {}}
test parseExpr-23.2 {TIP 582: comments} -constraints testexprparser -body {
    testexprparser "7 #\n* 8 " -1
} -result {- {} 0 subexpr {7 #
*} 5 operator # 0 subexpr 7 1 text 7 0 subexpr * 1 text * 0 {}}

# cleanup
cleanupTests
return