I know this is a simple problem - to 'most everyone but me, but I cannot
see why I’m getting this error. I’ve explored things with ruby-debug,
and with irb inside of the debugger, and I simply cannot replicate the
error.
The code (this most of a little routine for converting an HTML file to a
textile marked up file):
input
filein = open( "{whatever}" )
fi = filein.readlines
output
fileout = open( "_textile.txt", 'w')
delta = [
["
", ‘’],
["", ‘’]] # for brevity, I’ve truncated this array - you get
the idea, I assume
ld = delta.length
i = 0
until i > ld
#results = fi[0].gsub( delta[i][0], delta[i][1] ) <= in an attempt
isolate error, I broke this into the following:
s1 = delta[i][0] # <= exception is thrown here
s2 = delta[i][1]
results = fi[0].gsub( s1, s2 )
i += 1
end
The error msg:
$ ruby textilemkr.rb
textilemkr.rb:55:in main': undefined method[]’ for nil:NilClass
(NoMethodError)
from textilemkr.rb:66
I’ve confirmed that delta[1][0] is valid, that “i” is 0 when error
occurs, etc.
If it works in irb, why doesn’t it work when I run the routine via the
interpreter? What obvious thing am I missing?
All help will be gratefully accepted.
Tom
Hi –
On Mon, 16 Jun 2008, Tom C. wrote:
output
s2 = delta[i][1]
I’ve confirmed that delta[1][0] is valid, that “i” is 0 when error occurs,
etc.
If it works in irb, why doesn’t it work when I run the routine via the
interpreter? What obvious thing am I missing?
It doesn’t work in irb:
delta = [
?> ["
", ‘’],
?> ["", ‘’]] #
=> [["", “”], ["", “”]]
ld = delta.length
=> 2
i = 0
=> 0
until i > ld
s1 = delta[i][0] # <= exception is thrown here
s2 = delta[i][1]
i += 1
end
NoMethodError: undefined method `[]’ for nil:NilClass
The problem is that the length of the array is 2, but delta[2] is nil.
I’m reasonably sure that that’s when it’s failing, not when i is 0,
unless the shortened version is missing something that would make that
happen.
I would dispense with i entirely and just iterate over delta.
David
David A. Black wrote:
to a textile marked up file):
ld = delta.length
s1 = delta[i][0] # <= exception is thrown here
I would dispense with i entirely and just iterate over delta.
David
Nice. Thanks much, on both points. I never “saw” i get to 2, and so
didn’t see the error. Jeez. I do find it hard to be a weekend warrior
with Ruby. I lose bits between my ears during the workweek!
Thanks again for you help.
t.
–
Tom C., MS MA, LMHC
Private practice Psychotherapist
Bellingham, Washington, U.S.A: (360) 920-1226
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