
=== Bracket/paren depth tracking ===
Colon in key: expr=d['b:c'], value=2
Slice colon: expr=items[1:3], value=[20, 30]
Function call: expr=pair(1, 2), value=(1, 2)
Default arg colon: expr=pair(3), value=(3, ':')
Nested brackets: expr=matrix[0][1], value=2

=== Inline template literal tests ===
Empty nested: Template
With content: Template
Concatenation: Template
Mixed quotes: Template
Nested interp: Template

=== Backslashes not allowed in expressions (PEP 498/750) ===
Backslash in expression: SyntaxError
Escaped newline: SyntaxError

=== Format spec with special characters ===
