Quasiquotes API

quasiquotes is designed to make it easy to extend python syntax with arbitrary parsing logic. To define a new syntax enhancement, create an instance of a subclass of QuasiQuoter that overrides the quote_expr or quote_stmt methods.

class quasiquotes.quasiquoter.QuasiQuoter

Custom parsing logic for python

static locals_to_fast(frame, *, _locals_to_fast=<_FuncPtr object>, _pyobject=<class 'ctypes.py_object'>, _true=c_int(1))

Write the f_locals of frame back into the fast local storage.

Parameters:

frame : frame

The frame whose f_locals and fast will be synced.
quote_expr(expr, frame, col_offset)

Quote an expression.

This is called in the oxford brackets case: [$qq|...|]

Parameters:

expr : str

The expression to quote.

frame : frame

The stack frame where this expression is being executed.

col_offset : int

The column offset for the quasiquoter.
Returns:

v : any

The value of the quoted expression.
quote_stmt(stmt, frame, col_offset)

Quote a statment.

This is called in the enhanced with block case: with $qq: ...

Parameters:

stmt : str

The statement to quote. This will have the unaltered indentation.

frame : frame

The stack frame where this statement is being executed.

col_offset : int

The column offset for the quasiquoter.

quote_stmt has no value. It is used to run normal imperitive code like you would normally put in the body of a context manager.

quote_expr has a value. It is used to create expressions that can be plugged into other expressions.

Both quote_stmt and quote_expr are passed 3 arguments:

  1. String representing the body of either the expression or statement
  2. Stackframe where this is being executed
  3. Column offset of the quasiquoter

The string will be the pre-built string literal the we constructed at decode time. The stackframe will be the python stackframe where the quoted statement or expression is being used. Finally the column offset will be the pre-built integer constant that represents the offset of the quasiquote token.

Each quasiquoter is free to do whatever it wants with this information, including mutation of the calling frame’s locals, compiling new code, or just ignoring the body.

A quasiquoter does not need to implement both quote_stmt and quote_expr. In some cases, it only makes sense to support one of these features. If a quote type is used syntactically; however, the runtime quasiquoter does not support this featere then a quasiquotes.quasiquoter.QQNotImplementedError exception will be raised.