Tcl debugging

[prashhiit]

set x 1
if {$x == 1} {
puts "x=1"
} else {
jsfdlkdsjfh
}


Hello All,

In the above code, there is a Syntax error in the 'else' part. If I run this in tclsh, I don't get any error. Unlike c/C++, tclsh does not give all syntax errors in the script. Since, x=1 if condition is always satisfied so it never enters into else part.

My Question is "How can I get syntax error in the 'else' part. What should I do to get all Syntax errors in my Tcl Script."


Please suggest me


Thanks
Prashanth

 

[Bong]

There's only a "syntax error" because you haven't defined a procedure called "jsfdlkdsjfh". How is the interpreter supposed to know that?

_________________
Bob Rashkin

 

[prashhiit]

Hi


That is what my question. I don't get any error even if "jsfdlkdsjfh" procedure is not defined. What should I do to get error message "procedure not defined".


Please also consider this case

set x 1
if {$x ==1 } {
puts "x=1"
} else {
set x "End double quote is missing
}


in the 'else' part, end double quote is missed. When I run this code, I don't get any syntax error.

 

[mikrom]

You don't get any error because your procedures doesn't execute the [highlight]else-blocks[/highlight].

When you change the first procedure so it executes the [highlight]else-block[/highlight], for example to:

[highlight]set x 10[/highlight]
if {$x == 1} {
  puts "x=1"
} else {
  jsfdlkdsjfh
}

the you will get this error

C:\_mikrom\Work>tclsh85 prashhiit01.tcl
[highlight]invalid command name "jsfdlkdsjfh"[/highlight]
    while executing
"jsfdlkdsjfh"
    invoked from within
"if {$x == 1} {
  puts "x=1"
} else {
  jsfdlkdsjfh
}"
    (file "prashhiit01.tcl" line 2)

When you change the second procedure so it executes the [highlight]else-block[/highlight], for example to:

[highlight]set x 10[/highlight]
if {$x ==1 } {
  puts "x=1"
} else {
  set x "End double quote is missing
}

the you will get this error

C:\_mikrom\Work>tclsh85 prashhiit02.tcl
[highlight]missing "[/highlight]
    while executing
"set x "End double quote is missing
"
    invoked from within
"if {$x ==1 } {
  puts "x=1"
} else {
  set x "End double quote is missing
}"
    (file "prashhiit02.tcl" line 2)

In both cases, the error description says clearly what's wrong.

 

[prashhiit]

Yes, It throws error message only when it enters into else block.

This is not the case in C/C++.


Is there any Tcl debugger which displays all syntax errors in a block even if it does not enter into that particular block.


Please let me know

Thanks
Prashanth

 

[mikrom]

Tcl is interpreted language in difference to C which is compiled language, therefore the behaviour is different.

 

[mikrom]

Is there any Tcl debugger which displays all syntax errors in a block even if it does not enter into that particular block.

It's not debugging, but syntax checking. Try to google for [highlight]tcl syntax checker[/highlight]

I tried Nagelfar - A Tcl Syntax checker, which has found all errors you posted:

Checking file prashhiit01.tcl
prashhiit01.tcl: Line   5: W Unknown command "jsfdlkdsjfh"
Checking file prashhiit02.tcl
prashhiit02.tcl: Line   5: E Could not complete statement.
                             One double quote would complete the first line
                             One double quote would complete the script body at line 6.
Done (E/W/N: 1/1/0)

Maybe there are some (commercial) IDEs for Tcl development with a build in syntax checker...