feature: sniper mode (aka high fidelity code transformation)

[monperrus]

we only rewrite the changed nodes, keeping the original formatting.

see ROADMAP

[monperrus]

depends on #1168

[monperrus]

useful for repairnator and co

[tdurieux]

see #1358

[monperrus]

closed per #1927

[monperrus]

FYI:
An Algorithm for Layout Preservation in Refactoring Transformations
https://link.springer.com/chapter/10.1007/978-3-642-28830-2_3

[monperrus]

More papers on high-fidelity / layout preserving code transformation:

High-fidelity C/C++ code transformation (2017)
https://www.sciencedirect.com/science/article/pii/S0167642307000718/pdf

Detaching and reconstructing the documentary structure of source code (2010)
https://www.researchgate.net/profile/Gabor_Kusper/publication/284888833_ICAI2010-volume2/links/5659ad0408aeafc2aac4c23a/ICAI2010-volume2.pdf#page=401

Layout preserving parser for refactoring in Erlang (2009)
https://pdfs.semanticscholar.org/8487/eeda4c867e8f7cd13d83391488b2abec4a39.pdf

revcpp: A reversible c++ preprocessor (2015)
https://www.lrde.epita.fr/~sigoure/revcpp.pdf

Scrap you reprinter (2017)
https://www.cs.kent.ac.uk/people/staff/dao7/publ/reprinter2017.pdf

[monperrus]

Transformation tools with high-fidelity / layout preserving features (thanks to @jurgenvinju):

• ASF+SDF, superseeded by Rascal (generic)
• StrategoXT (generic)
• Cscout (for C)
• HaRe (for Haskell)
• Clair for C++

[jurgenvinju]

Tools:

• Clair is based on Rascal, provides concrete syntax matching for an external C++ parser

Relevant papers:

• about Clair: "Concrete syntax with black box parsers" https://homepages.cwi.nl/~jurgenv/papers/Programming-2019.pdf
• Term Rewriting with Layout: https://homepages.cwi.nl/~jurgenv/papers/RULE-2000.pdf
• "First Class Layout" chapter in https://homepages.cwi.nl/~jurgenv/papers/thesis-2005.pdf

[jurgenvinju]

the paper which coined the term "hifi" transformation for "no loss of layout and source code comments":

"High Fidelity C/C++ Code Transformation" by Daniel Waddington and Bin Yao https://www.researchgate.net/publication/222998573_High-Fidelity_CC_Code_Transformation

[monperrus]

FYI, JavaParser calls this feature "lexical preservation", see @ftomassetti's post
https://tomassetti.me/lexical-preservation-javaparser/

[jlundhol]

This paper by Rodin T. A. Aarssen and Tijs van der Storm suggesting "Separator Syntax Trees" might be of interest:

High-fidelity metaprogramming with separator syntax trees (2020)
https://dl.acm.org/doi/abs/10.1145/3372884.3373162