gistfile1.txt

longMethod( int y ) {
  int x;
  x = 0;
  // ... 
  // IRRELEVANCY #0: 87 lines that neither read nor write x
  // ...
  if( y == 17 ) {
    x = 1;
  }
  // ...
  // IRRELEVANCY #1: 87 more lines that neither read nor write x
  // ...
  if( someVeryInterestingConditionHavingNothingToDoWithX() ) {
    doTheThing(x)
    }
  // ...
  // IRRELEVANCY #2: 87 more lines that neither read nor write x
  // ... 
  }
  
////////////////
// After joining declartion to initialization and moving it as far *down*...
// we can go 87 lines into this method *without* having to remember what X is.
longMethod( int y ) {
  // ... 
  // IRRELEVANCY #0: 87 lines that neither read nor write x
  // ...
  int x=0
  if( y == 17 ) {
    x = 1;
  }
  // ...
  // IRRELEVANCY #1: 87 more lines that neither read nor write x
  // ...
  if( someVeryInterestingConditionHavingNothingToDoWithX() ) {
    doTheThing(x)
    }
  // ...
  // IRRELEVANCY #2: 87 more lines that neither read nor write x
  // ... 
  }
  
////////////////
// After extraction we killed an if and made the single-assign aspect of x obvious
// in languages with immutability, we just made x immutable (const)!
longMethod( int y ) {
  // ... 
  // IRRELEVANCY #0: 87 lines that neither read nor write x
  // ...
  int x=chooseX(y)
  // ...
  // IRRELEVANCY #1: 87 more lines that neither read nor write x
  // ...
  if( someVeryInterestingConditionHavingNothingToDoWithX() ) {
    doTheThing(x)
    }
  // ...
  // IRRELEVANCY #2: 87 more lines that neither read nor write x
  // ... 
  }
    

////////////////
// We keep moving it down, but now it's easy to see we can move it *in*
// Now we've made IRRELEVANCY #1 visibly irrelevant, and IRRELEVANCY #2 visibly irrelevant
longMethod( int y ) {
  // ... 
  // IRRELEVANCY #0: 87 lines that neither read nor write x
  // ...
  // ...
  // IRRELEVANCY #1: 87 more lines that neither read nor write x
  // ...
  if( someVeryInterestingConditionHavingNothingToDoWithX() ) {
    int x = chooseX(y)
    doTheThing(x)
    }
  // ...
  // IRRELEVANCY #2: 87 more lines that neither read nor write x
  // ... 
  }