https://github.com/aviralg/tastr
Type AST for R
https://github.com/aviralg/tastr
Last synced: about 2 months ago
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Type AST for R
- Host: GitHub
- URL: https://github.com/aviralg/tastr
- Owner: aviralg
- License: apache-2.0
- Created: 2020-02-24T19:05:49.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2020-05-07T18:27:33.000Z (about 6 years ago)
- Last Synced: 2025-01-28T03:28:53.000Z (over 1 year ago)
- Language: C++
- Homepage:
- Size: 1.27 MB
- Stars: 0
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# tastr: Type AST for R
[](https://opensource.org/licenses/Apache-2.0)
[](https://travis-ci.org/aviralg/tastr)
`tastr` is a library that implements a grammar for R types. It provides functions to parse types from input streams (files, strings, etc.) to C++ objects. It also provides the reverse functionality to unparse these objects.
The Type AST is modeled using C++ classes. The design relies heavily on unique ownership, i.e., an AST node holds unique references to its child nodes.
The grammar is implemented using [`flex`](https://westes.github.io/flex/manual/) and [`bison`](https://www.gnu.org/software/bison/manual/bison.html).
## Installation
To obtain the project source, run:
`$` `git clone https://github.com/aviralg/tastr.git`
To build the project, run:
`$` `make`
This will build the following artifacts:
- **Static library**: `build/lib/libtastr.a`
- **Shared library**: `build/lib/libtastr.so`
- **Executable**: `build/bin/tastr`
To clean the build artifacts, run:
`$` `make clean`
To execute tests, run:
$ make test
For building and testing in parallel, invoke `make` with `-j` flag.
## Usage
The `tastr` executable (`build/bin/tastr`) parses type declarations from different sources and unparses them back.
```
> build/bin/tastr --help
Parse type declarations.
Usage:
tastr [OPTION...]
-h, --help Print usage
-l, --lexer Debug lexer
-p, --parser Debug parser
-a, --ast Show AST structure
-s, --style Style output
```
### Render input
Pass the filename to render the input as is (retains spaces, newlines and comments):
Pass `--style` flag to render with styling.
To read the input from stdin pass `-` argument (press `Ctrl-D` to simulate end of input).
Input can also be directly parsed from the argument if it is quoted using `"` or `'`.
### View AST structure
Use `--ast` flag to view the ast structure without any styling.
Use `--style` flag along with `--ast` to view the ast structure with styling.
## Type Grammar
```
: "integer"
| "int"
| "i"
: "double"
| "dbl"
| "d"
: "complex"
| "clx"
| "x"
: "character"
| "chr"
| "s"
: "logical"
| "lgl"
| "l"
: "raw"
| "r"
:
|
|
|
|
: "^"
:
|
|
: "environment"
| "env"
| "t"
: "expression"
| "exr"
| "e"
: "language"
| "lng"
| "g"
: "symbol"
| "sym"
| "y"
: "externalptr"
| "ept"
| "p"
: "bytecode"
| "bcd"
| "b"
: "pairlist"
| "plt"
: "s4"
: "weakref"
| "wrf"
| "w"
: "dataframe"
| "df"
: "any"
| "*"
: "???"
: "[" "]"
: "list" "<" ">"
| "lst" "<" ">"
: "struct" "<" ">"
| "srt" "<" ">"
| "struct" "<" ">"
| "srt" "<" ">"
: "tuple" "<" ">"
| "tpl" "<" ">"
| "tuple" "<" ">"
| "tpl" "<" ">"
:
| ","
: ":"
| "^" ":"
:
| ","
:
| "..."
:
| ","
: "<" ">"
| "<" ">"
| "any"
: "=>"
: "(" ")"
:
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
:
| "|"
: "?"
| "?"
:
|
|
: "type" ";"
:
|
```
## Useful Resources
### Bison and Flex
- [Flex Token Order](https://stackoverflow.com/questions/22444094/flex-token-order)
- [UTK Bison Notes](http://web.eecs.utk.edu/~bvanderz/teaching/cs461Sp11/notes/bison/)
- [Parsing rule for empty files](https://stackoverflow.com/questions/11047227/no-error-while-parsing-empty-file-yacc-lex)
- [Dynamic file loading in Flex](https://stackoverflow.com/questions/31839746/loading-external-files-flex-bison-yyin)
- [Redefine `YY_INPUT` in Flex](https://stackoverflow.com/questions/1920604/how-to-make-yy-input-point-to-a-string-rather-than-stdin-in-lex-yacc-solaris)
- [C++ istream with Flex](https://stackoverflow.com/questions/9628099/c-istream-with-lex)
- [Bison/Flex Example](https://github.com/ezaquarii/bison-flex-cpp-example)
- [Read from C++ streams in Flex](https://stackoverflow.com/questions/780676/string-input-to-flex-lexer)
- [Lex and Yacc Tutorial](https://www.epaperpress.com/lexandyacc/index.html)
- [Parsing strings in Flex](http://dinosaur.compilertools.net/flex/flex_11.html)
- [Bison/Flex Example](https://coldfix.eu/2015/05/16/bison-c++11/)
- [Unique Pointer as a Semantic Value in Bison](http://www.comrite.com/wp/c11-stdunique_ptr-as-semantic-value-in-bison-c-mode/)
- [Resolving Grammar Conflicts](https://efxa.org/2014/05/17/techniques-for-resolving-common-grammar-conflicts-in-parsers/)
- [Bison/Flex Example](http://www.kylheku.com/cgit/txr/tree/parser.l)
- [Bison/Flex Example](http://www.jonathanbeard.io/tutorials/FlexBisonC++)
- [Bison/Flex Example](http://panthema.net/2007/flex-bison-cpp-example/)
- [Bison/Flex Example](https://panthema.net/2007/flex-bison-cpp-example/flex-bison-cpp-example-0.1/doxygen-html/index.html)
- [Bison/Flex Example](https://github.com/EmilGedda/Leonardo)
### C++: Unique Pointers and Polymorphism
- [Arguments and Unique Pointers](https://vladris.com/blog/2016/03/11/arguments-and-smart-pointers.html)
- [Smart Pointer Parameters](https://herbsutter.com/2013/06/05/gotw-91-solution-smart-pointer-parameters/)
- [Move Constructors and Multiple Inheritance](https://stackoverflow.com/questions/10114701/move-constructors-and-multiple-inheritance)
- [Copy Constructors and Unique Pointer](https://stackoverflow.com/questions/16030081/copy-constructor-for-a-class-with-unique-ptr)
- [Rules for Smart Pointers](https://www.modernescpp.com/index.php/c-core-guidelines-rules-to-smart-pointers)
- [Using Smart Pointers as Class Members](https://stackoverflow.com/questions/15648844/using-smart-pointers-for-class-members)
- [Cloning, Covariant Return and Smart Pointer](https://www.fluentcpp.com/2017/09/12/how-to-return-a-smart-pointer-and-use-covariance/)
- [How I Declare my Class and Why](http://howardhinnant.github.io/classdecl.html)
- [Polymorphic Cloning and CRTP](https://katyscode.wordpress.com/2013/08/22/c-polymorphic-cloning-and-the-crtp-curiously-recurring-template-pattern/)
- [Delegating Constructors](https://arne-mertz.de/2015/08/new-c-features-inherited-and-delegating-constructors/)
- [`==` operator and Polymorphism](https://stackoverflow.com/a/565785)
- [Move constructors and inheritance](https://stackoverflow.com/questions/15351341/move-constructors-and-inheritance)
- [Move assignment operator and inheritance](https://stackoverflow.com/questions/50854598/inheritence-of-the-move-assignment-operator-in-c)
- [Move assignment on self](https://stackoverflow.com/questions/9322174/move-assignment-operator-and-if-this-rhs)
- [C++ `final` keyword](https://smartbear.com/blog/develop/use-c11-inheritance-control-keywords-to-prevent-in/)
### Make and Code Compilation
- [Compiling a static library in linux](https://stackoverflow.com/questions/2734719/how-to-compile-a-static-library-in-linux)
- [Compiling C/C++ software](https://gist.github.com/gubatron/32f82053596c24b6bec6)
### R
- [Various uses of quoting in R](https://stat.ethz.ch/R-manual/R-devel/library/base/html/Quotes.html)
### Miscellaneous
- [Unicode Characters in the 'Punctuation, Open' Category](https://www.fileformat.info/info/unicode/category/Ps/list.htm)
- http://www.fileformat.info/info/unicode/block/control_pictures/images.htm
- https://www.htmlsymbols.xyz/arrow-symbols
## TODO
1. Check `clone_impl`, it should be empty for abstract base classes and defined for concrete classes.
\\u[0-9A-Fa-f]{1,4} { get_identifier().push_back(yytext); }
\\U[0-9A-Fa-f]{1,8} { get_identifier().push_back(yytext); }
\\u{LBRACE}[0-9A-Fa-f]{1,4}{RBRACE} { get_identifier().push_back(yytext); }
\\U{LBRACE}[0-9A-Fa-f]{1,8}{RBRACE} { get_identifier().push_back(yytext); }
\\[0-7]{2} { get_identifier().append("0"); get_identifier().push_back(yytext[1]); get_identifier().push_back(yytext[2]); }
\\[0-7]{3} { get_identifier().append(yytext); }