sq/grammar
Neil O'Toole f07edef14d
Add flag --src.schema (#326)
* Support for --src.schema in commands "slq", "sql", and "inspect"
2023-11-18 17:05:48 -07:00
..
testdata SLQ support for column aliases (#150) 2023-03-18 22:58:00 -06:00
generate.go Clean up the antlr tooling (#131) 2022-12-24 09:43:21 -07:00
generate.sh Add flag --src.schema (#326) 2023-11-18 17:05:48 -07:00
README.md Clean up the antlr tooling (#131) 2022-12-24 09:43:21 -07:00
SLQ.g4 Add flag --src.schema (#326) 2023-11-18 17:05:48 -07:00

SLQ Grammar

The query language used by sq is formally known as SLQ. The grammar is defined in SLQ.g4, which is an ANTLR4 grammar.

There's a bunch of valid sample input in the testdata dir.

The antlr4 tool generates the parser / lexer files from the grammar. Being that antlr4 is Java-based, Java must be installed to regenerate from the grammar. The process is encapsulated in generate.sh (or execute go generate ./...).

The generated .go files ultimately end up in package libsq/ast/internal/slq. Files in this directory should not be directly edited.

The libsq/ast.Parse function takes a SLQ input string and returns an *ast.AST. The entrypoint that accepts the SLQ string is libsq.ExecuteSLQ, which ultimately invokes ast.Parse.

Working with the grammar

You probably should install the antlr tools.

pip install antlr4-tools

You may also find antlr4ts useful.

npm install antlr4ts

And there are various IDE plugins available.

In particular, note the VS Code extension.