replacetext(), deletetext(), inserttext()

ID:195048
 
Aug 2 2008, 4:02 pm
One-liner snippets from my tiny texthandling library.
proc
    replacetext(t,t2,t3)return copytext(t,1,findtext(t,t2))+t3+copytext(t,findtext(t,t2)+length(t2),0)
    deletetext(t,t2)    return copytext(t,1,findtext(t,t2))+copytext(t,findtext(t,t2)+length(t2),0)
    inserttext(t,t2,n)  return copytext(t,1,n>0?n+1 : length(t)+1)+t2+copytext(t,n>0?n+1 : length(t)+1,0)


mob/verb
    HelloMars()src<<replacetext("Hello world!","world","Mars")
    //Replaces "world" with "Mars"
    HelloWorld()src<<deletetext("Hello stuff in the world!","stuff in the ")
    //Outputs "Hello world"
    HelloBLAHWorld()src<<inserttext("HelloWorld","BLAH",5)
    //Inserts "BLAH" after "Hello", which is 5 characters long.
Sep 23 2008, 9:16 pm
Kaiochao wrote:
One-liner snippets from my tiny texthandling library.
> proc
>   replacetext(t,t2,t3)return copytext(t,1,findtext(t,t2))+t3+copytext(t,findtext(t,t2)+length(t2),0)
>   deletetext(t,t2)    return copytext(t,1,findtext(t,t2))+copytext(t,findtext(t,t2)+length(t2),0)
>   inserttext(t,t2,n)  return copytext(t,1,n>0?n+1 : length(t)+1)+t2+copytext(t,n>0?n+1 : length(t)+1,0)
>


Not only do these procs leave much to be desired in the way of iterations (replacetext() and deletetext() would only replace/delete the first instance of t2), they don't work very well, and don't offer much in the way of differentiating between case-sensitivity (you only allow for case-insensitive operations).

The following breaks your first two procs:
client/verb/Test()
// Hello worldMarso world:
    src << replacetext("Hello world", "Earth", "Mars")
    
// Hello worldlo world
    src << deletetext("Hello world", "Mars")


A more proper replacetext() function would look like this:
proc
    replacetext(haystack, needle, replace)
        var
            needleLen = length(needle)
            replaceLen = length(replace)
            pos = findtext(haystack, needle)
        while(pos)
            haystack = copytext(haystack, 1, pos) + \
                replace + copytext(haystack, pos+needleLen)
            pos = findtext(haystack, needle, pos+replaceLen)
        return haystack