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[REBOL] Re: [refactoring s-c?]

From: rebol665:ifrance at: 16-Mar-2002 18:24

Hi Ladislav, I am even more confused, but I like that! I can play the luke-who-wants-to-be-a-jedi part, master Yoda. 1. Assuming that nonsame is correct, I have tested that : a: 100 word1: nonsame 'a
>> s-c? 'a 'word1
== true I was puzzled because I thought that use will create a new context and return something bound to this context. I had found an interesting example of that in the escribe archives : a: 1 block: [a] use [a] [a: 2 append tail block [a]]
>> block
== [a a]
>> s-c? first block second block
== false Fortunately I realized my mistake and that the correct testing was :
>> s-c? 'a word1
== false That was confirmed by
>> s-c? 'a nonsame 'a
== false Assertion 1 : nonsame returns a word bound to another context. Assertion 2 : this context is created by use. Assertion 3 : nonsame returns a word with the same spelling.
>> mold word1
== "a"
>> mold 'a
== "a" I am aware that assertion 1 and assertion 3 are certainly bound because it is not possible to have two words with the same spelling in the same context. 2. From (1) I have learned that use was required to create a new word with the same spelling but different. As for comparing nonsame1 and nonsame, I have learned nothing. As far as I can tell they are equivalent :
>> word2: nonsame1 'a
== a
>> s-c? 'a word2
== false 3. Why reduce ? I have still no idea, but I can try removing it and see what happens. ns: func [ word [word!] {the given word} ][ use [word][word] ]
>> ns 'a
** Script Error: word has no value ** Where: ns ** Near: word Definitively wrong ns: func [ word [word!] {the given word} ][ use [word] reduce [word] ]
>> ns 'a
== 100 Returns a value. It is not good. ns: func [ word [word!] {the given word} ][ use [word] reduce ['first reduce [word]] ]
>> ns 'a
== a Looks better. first is used to extract a word rather than a value. An extra block is needed to be the body that use requires. However this is not good because :
>> same? 'a ns 'a
== true Assertion 4 : I am exhausted ! 4. As far as I can tell now, I am not able to explain why nonsame is better than nonsame1. All my experiments have fail to prove any of : - nonsame1 and nonsame do not return always the same result - nonsame1 has an undesired side-effect - nonsame1 rises an error 5. Epilogue Learning that I know nothing is indeed a valuable lesson. Knowing that is certainly better than pretending to know something that I don't. I don't know if I am ready for understanding the truth. It is not for the apprentice to decide. I have spent half my day with all these trials and must return now to a normal life ! Hoping for the best Patrick