Implement consider-merging-isinstance

[harupy]

#970

[harupy]

I'm not sure if this is intended, but the start location of a BoolOp expression is the start location of or.

[harupy]

RustPython's code:

https://github.com/RustPython/RustPython/blob/18af44b7c7410c3448df1f3b080bd358e586d265/compiler/parser/python.lalrpop#L758

OrTest: ast::Expr = {
    <e1:AndTest> <location:@L> <e2:("or" AndTest)*> <end_location:@R> => {
        if e2.is_empty() {
            e1
        } else {
            let mut values = vec![e1];
            values.extend(e2.into_iter().map(|e| e.1));
            ast::Expr {
                location,
                end_location: Some(end_location),
                custom: (),
                node: ast::ExprKind::BoolOp { op: ast::Boolop::Or, values }
            }
        }
    },
};

[harupy]

Moving <location:@L> before <e1:AndTest> seems to work?

https://github.com/harupy/RustPython/blob/3835575a831dafe48fa4ddbae895960a377f1227/compiler/parser/python.lalrpop#L759

OrTest: ast::Expr = {
    <location:@L> <e1:AndTest> <e2:("or" AndTest)*> <end_location:@R> => {
    ^^^^^^^^^^^^^
        if e2.is_empty() {
            e1
        } else {
            let mut values = vec![e1];
            values.extend(e2.into_iter().map(|e| e.1));
            ast::Expr {
                location,
                end_location: Some(end_location),
                custom: (),
                node: ast::ExprKind::BoolOp { op: ast::Boolop::Or, values }
            }
        }
    },
};

[harupy]

import ast

# Visitor to print out node locations
class V(ast.NodeVisitor):
    def visit_BoolOp(self, node: ast.BoolOp) -> None:
        print(
            node.__class__.__name__,
            (node.lineno, node.col_offset),
            (node.end_lineno, node.end_col_offset),
        )
        self.generic_visit(node)

V().visit(ast.parse("a or b or c"))

prints out:

BoolOp (1, 0) (1, 11)

[charliermarsh]

Oh cool. Do you want to submit an upstream PR for this? Or I can.

[harupy]

Filed RustPython/RustPython#4306.