>* I have to manually remove the 0x, even though it is a very common way of
>expressing hex numbers
Adding a few lines to NumberParser>>#nextNumber enables it to parse 0x...
-----------------------------------
((sourceStream peekFor: $r)) ifTrue: ["<base>r<integer>"
...
]
ifFalse: [
(sourceStream peekFor: $x) ifTrue: [ "0x<integer>"
(integerPart isZero and: [ numberOfTrailingZeroInIntegerPart =
1]) ifFalse: [
sourceStream skip: -1.
^ self expected: 'one leading 0 before x'
].
^ self nextUnsignedIntegerBase: 16
]
].
----------------------------------
0x10. "16"
0xFF + 16rFF = (2 * 0xff). "true"
Best regards,
Henrik
-----Opprinnelig melding-----
Fra: Pharo-users [mailto:pharo-users-boun...@lists.pharo.org] På vegne av Peter
Uhnak
Sendt: 20 January 2017 16:16
Til: pharo-users@lists.pharo.org
Emne: [Pharo-users] Tools for easy subtext extraction from text
Hi,
what are the tools available from easier text extraction?
The input is unstructured text, but I want to extract portion from it.
I am not looking for an engineered approach (writing a parser or something),
but something that can be done quickly by hand (i.e. interactively).
For example I have string
str = ' Temperature 0 37C (98F) [0x25] (TMPIN0)'
Now I want to extract '0x25' from it and convert it into integer
In Ruby it is dead simple:
str[/\[(.*)\]/,1].hex # "=> 37" , or .to_i(16)
In Pharo I have to break my fingers first:
rx := '.*\[0x(.*)\].*' asRegex.
rx matches: str.
Integer readFrom: (rx subexpression: 2) base: 16 "=>37".
* I have to know that to get subexpression I have to match first to manipulate
the internal state
* I have to store the matcher to access the subexpression
* I need to explicitly use some global variable Integer as a conversion utility
to convert hex to dec
* I have to manually remove the 0x, even though it is a very common way of
expressing hex numbers
So the question is:
do we have a better way to do these things? And as I've mentioned - the use
case is interactive coding where you often throw the code away when you are
done; so dead easy to write and use.
Thanks,
Peter
