Evaluate which refactoring we want to support

Martin Fowlers book about refactoring gives a deep inside into  different refactorings. We should decide which ones we want to implement. What are the dependencies of this refactorings etc.. 

Normally you make a local change and then fix up all the global changes. For the global changes we need the symbols database. The local changes can need the AST but some are so simple that it should work without. Because they are very similar they can share much code. So creating building blocks could be quite useful if we see code duplication. We should think about UI elements too because in many cases we need to select multiple elements.

The book is listing following refactoring:

Chapter 6. Composing Methods .............................................................................. 89
Extract Method........................................................................................................ 89
Inline Method........................................................................................................... 95
Inline Temp.............................................................................................................. 96
Replace Temp with Query .................................................................................... 97
Introduce Explaining Variable............................................................................. 101
Split Temporary Variable..................................................................................... 104
Remove Assignments to Parameters ............................................................... 107
Replace Method with Method Object ................................................................ 110
Substitute Algorithm ............................................................................................. 113
Chapter 7. Moving Features Between Objects.................................................... 115
Move Method ........................................................................................................ 115
Move Field ............................................................................................................. 119
Extract Class ......................................................................................................... 122
Inline Class............................................................................................................ 125
Hide Delegate ....................................................................................................... 127
Remove Middle Man............................................................................................ 130
Introduce Foreign Method................................................................................... 131
Introduce Local Extension................................................................................... 133
Chapter 8. Organizing Data .................................................................................... 138
Self Encapsulate Field......................................................................................... 138
Replace Data Value with Object ........................................................................ 141
Change Value to Reference ............................................................................... 144
Change Reference to Value ............................................................................... 148
Replace Array with Object .................................................................................. 150
Duplicate Observed Data .................................................................................... 153
Change Unidirectional Association to Bidirectional ........................................ 159
Change Bidirectional Association to Unidirectional ........................................ 162
Replace Magic Number with Symbolic Constant ............................................ 166
Encapsulate Field................................................................................................. 167
Encapsulate Collection........................................................................................ 168
Replace Record with Data Class....................................................................... 175
Replace Type Code with Class .......................................................................... 176
Replace Type Code with Subclasses ............................................................... 181
Replace Type Code with State/Strategy........................................................... 184
Replace Subclass with Fields............................................................................. 188
Chapter 9. Simplifying Conditional Expressions ................................................. 192

Decompose Conditional ...................................................................................... 192
Consolidate Conditional Expression................................................................. 194
Consolidate Duplicate Conditional Fragments ................................................ 196
Remove Control Flag........................................................................................... 197
Replace Nested Conditional with Guard Clauses ........................................... 201
Replace Conditional with Polymorphism .......................................................... 205
Introduce Null Object ........................................................................................... 209
Introduce Assertion.............................................................................................. 216
Chapter 10. Making Method Calls Simpler........................................................... 220
Rename Method................................................................................................... 221
Add Parameter...................................................................................................... 222
Remove Parameter.............................................................................................. 223
Separate Query from Modifier............................................................................ 225
Parameterize Method .......................................................................................... 228
Replace Parameter with Explicit Methods........................................................ 230
Preserve Whole Object ....................................................................................... 232
Replace Parameter with Method ....................................................................... 235
Introduce Parameter Object ............................................................................... 238
Remove Setting Method...................................................................................... 242
Hide Method.......................................................................................................... 245
Replace Constructor with Factory Method....................................................... 246
Encapsulate Downcast........................................................................................ 249
Replace Error Code with Exception .................................................................. 251
Replace Exception with Test .............................................................................. 255
Chapter 11. Dealing with Generalization.............................................................. 259
Pull Up Field .......................................................................................................... 259
Pull Up Method ..................................................................................................... 260
Pull Up Constructor Body.................................................................................... 263
Push Down Method.............................................................................................. 266
Push Down Field .................................................................................................. 266
Extract Subclass................................................................................................... 267
Extract Superclass ............................................................................................... 272
Extract Interface ................................................................................................... 277
Collapse Hierarchy............................................................................................... 279
Form Template Method....................................................................................... 280
Replace Inheritance with Delegation................................................................. 287
Replace Delegation with Inheritance................................................................. 289
Chapter 12. Big Refactorings ................................................................................. 293
Tease Apart Inheritance...................................................................................... 294
Convert Procedural Design to Objects ............................................................. 300
Separate Domain from Presentation................................................................. 302
Extract Hierarchy.................................................................................................. 306

I would propose that we add an user story for every refactoring we want to implement .