String to integer conversion

[Lee Salzman]

I committed the following:

s@(String traits) as: i@(Integer traits) &radix: radix
"Reads a radix-(10) Integer from the string."
[
   (s isNotEmpty /\ [s first = $-])
     ifTrue:
       [^ ((s copyFrom: 1) as: i &radix: radix) negated].
   radix ifNil: [radix: 10].
   s inject: 0 into:
     [| :n :c | (c isDigit: radix) ifFalse: [^ n].
      n * radix + (c toDigit: radix)]
].

Although, this may be better off just using the lexer or Number 
readFrom: String.

Lee

Márton Sasvári (IJ/ETH) wrote:
> Hi,
> 
> The #as: method converting Strings to Integers does not work on negative 
> values (returns zero) as the characters of the string are checked to be 
> digits and the minus sign isn't one. I've attached three method versions 
> working correctly not being able to descide which is the slate-iest in 
> style.
> 
> Regards,
> Marton
> 
> 
> ------------------------------------------------------------------------
> 
> 
> s@(String traits) as: _@(Integer traits) &radix: radix
> [
>   s size = 0 ifTrue: [^ 0].
>   radix ifNil: [radix: 10].
>   (s at: 0) = $-
>     ifTrue: [
>       (s sliceFrom: 1) inject: 0 into:
> 	[| :n :c | (c isDigit: radix) ifFalse: [^ n].
>        	 n * radix - (c toDigit: radix)]]
>     ifFalse: [s inject: 0 into:
>       [| :n :c | (c isDigit: radix) ifFalse: [^ n].
>        n * radix + (c toDigit: radix)]]
> ].
> 
> s@(String traits) as: _@(Integer traits) &radix: radix
> [| answer |
>   radix ifNil: [radix: 10].
>   answer: 0.
>   s size > 0 ifTrue: [| negate start |
>     (s at: 0) = $- 
>       ifTrue: [negate: True. start: 1]
>       ifFalse: [negate: False. start: 0].
>     start below: s size do: [| :i c |
>       c: (s at: i).
>       (c isDigit: radix) ifFalse: [^ answer].
>       answer: answer * radix + (c toDigit: radix)].
>     negate ifTrue: [answer: answer * -1]].
>   answer
> ].
> 
> s@(String traits) as: _@(Integer traits) &radix: radix
> [| op digits |
>   s size = 0 ifTrue: [^ 0].
>   radix ifNil: [radix: 10].
>   (s at: 0) = $-
>     ifTrue: [op: #-. digits: (s sliceFrom: 1)]
>     ifFalse: [op: #+. digits: s].
>   digits inject: 0 into:
>     [| :n :c | (c isDigit: radix) ifFalse: [^ n].
>      op sendWith: n * radix with: (c toDigit: radix)]
> ].
>