I’m trying to make a simple RPN calculator that reads in regular
expressions from a file and evaluates them to execute code. Currently I
have these regular expressions stored in an array of class objects that
have 2 data objects (1. The regex itself and 2. The block of code that
should be executed when a match is found). An example of one of the read
in regex’s is below:
[0-9]+
lambda {|input| $myStack.push(input)}
Now, I get input from the user and compare that string to all the
regular expressions in my array. When a match is found, the code is
evaluated. So far it is working by entering in input one by one. Code
and an example are below.
while input = gets
for i in 0…$regexArray.length-1
if ( input =~ Regexp.new($regexArray[i].regex) )
eval($regexArray[i].code).call(input)
end
end
end
Example:
5
4
+
print
will give “9” as it should. However, I want to make it so I can enter
input in one line like:
5 4 + print
I’ve tried matching the input string with the regex with: myMatch =
regex.match(input)
but when I enter a string such as “123 456” only the last part (“456”)
is matched when I need to first match the (“123”). Any help would be
appreciated.
On Nov 14, 2011, at 10:23 PM, Trevor Daniels wrote:
Now, I get input from the user and compare that string to all the
end
I’ve tried matching the input string with the regex with: myMatch =
regex.match(input)
but when I enter a string such as “123 456” only the last part (“456”)
is matched when I need to first match the (“123”). Any help would be
appreciated.
If your valid expressions contain no whitespace, you can split your
input into individual tokens with split(/\s+/). As a minimal example,
this works fine:
-----Messaggio originale-----
Da: Sylvester K. [mailto:[email protected]]
Inviato: marted 15 novembre 2011 11:05
A: ruby-talk ML
Oggetto: Re: calculator program help
On Nov 14, 2011, at 10:23 PM, Trevor Daniels wrote:
Now, I get input from the user and compare that string to all the
end
I’ve tried matching the input string with the regex with: myMatch =
regex.match(input)
but when I enter a string such as “123 456” only the last part (“456”)
is matched when I need to first match the (“123”). Any help would be
appreciated.
If your valid expressions contain no whitespace, you can split your
input
into individual tokens with split(/\s+/). As a minimal example, this
works
fine:
-----Messaggio originale-----
Da: Trevor Daniels [mailto:[email protected]]
Inviato: luned 14 novembre 2011 22:24
A: ruby-talk ML
Oggetto: calculator program help
I’m trying to make a simple RPN calculator that reads in regular
expressions
from a file and evaluates them to execute code. Currently I have these
regular expressions stored in an array of class objects that have 2 data
objects (1. The regex itself and 2. The block of code that should be
executed when a match is found). An example of one of the read in
regex’s is
below:
[0-9]+
lambda {|input| $myStack.push(input)}
Now, I get input from the user and compare that string to all the
regular
expressions in my array. When a match is found, the code is evaluated.
So
far it is working by entering in input one by one. Code and an example
are
below.
while input = gets
for i in 0…$regexArray.length-1
if ( input =~ Regexp.new($regexArray[i].regex) )
eval($regexArray[i].code).call(input)
end
end
end
Example:
5
4
+
print
will give “9” as it should. However, I want to make it so I can enter
input
in one line like:
5 4 + print
I’ve tried matching the input string with the regex with: myMatch =
regex.match(input)
but when I enter a string such as “123 456” only the last part (“456”)
is
matched when I need to first match the (“123”). Any help would be
appreciated.
