Re: Optimizing nested if statements?

> Therefore, I am looking for a syntax-to-syntax transformation. In
> other words, I want an actual semantically equivalent, yet
> syntactically different program.


This is precisely what the FermaT transformation system provides.


If z-1.wsl is the WSL program:


IF @a?
    THEN IF @b?
                  THEN IF @c?
                                THEN @S1
                            ELSIF @d?
                                THEN @S2 FI FI
ELSIF @e?
    THEN @S3 FI


Then run this program:


% dotrans z-1.wsl Align_Nested_Statements posn=1,1,2,1,1


This transforms z-1.wsl to z-2.wsl:


IF @a?
    THEN IF @b? AND @c?
                  THEN @S1
              ELSIF @b? AND @d?
                  THEN @S2
              ELSIF @b?
                  THEN SKIP FI
ELSIF @e?
    THEN @S3 FI


FermaT is available under the GPL from:


http://www.cse.dmu.ac.uk/~mward/fermat.html


and


http://www.durham.ac.uk/martin.ward/fermat.html


FermaT has been used commercially in assembler to C migration projects.
See the papers on my web site for details.


Martin


Martin.Ward@durham.ac.uk http://www.cse.dmu.ac.uk/~mward/ Erdos number: 4
G.K.Chesterton web site: http://www.cse.dmu.ac.uk/~mward/gkc/

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