Patterns have an unusual parse tree, but now the matching should
at least be a bit easier to follow.
The TODO regarding not being able to pass down context to handle
var/let is still relevant, and can't be solved in the mapping alone.
Adds a test case 'Switch with labeled case pattern arguments' covering:
- case .implicit(isAcknowledged: false) — labeled bool literal
- case .thread(threadRowId: _, let rowId) — labeled wildcard + binding
The current output contains type errors: pattern_element::key is being
produced as name_expr instead of identifier. These will be fixed in the
following commit.
The switch_entry rule was capturing switch_pattern wrapper nodes instead of
drilling into them to extract the actual pattern nodes. This caused patterns
from switch cases to be lost during desugaring.
Changed the pattern match from:
(switch_entry pattern: (switch_pattern)* @pats ...)
to:
(switch_entry pattern: (switch_pattern pattern: @pats)* ...)
This now correctly extracts the pattern field from each switch_pattern node,
ensuring that patterns from cases like 'case 1:' and 'case .circle(let r):'
are preserved in the switch_case AST nodes.
Updated control-flow.txt corpus outputs to reflect the new behavior.
Previously, when a node was synthesized it would always take the
location from the node that matched the current rule. This resulted
in overly broad locations however.
For (foo #{bar}) we now take the location of the 'bar' node.
For non-leaf nodes we merge all its child node locations.
When a field pattern has a bare capture with no preceding pattern
atom (i.e. `foo: @bar`), implicitly use a true wildcard (`_`,
match_unnamed: true) as the node pattern, making it equivalent to
`foo: _ @bar`.
This is a convenience shorthand: in practice every `field: _ @cap`
in the Swift rules can now be written more concisely as `field: @cap`.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
A left fold over an iterable where the first element seeds the accumulator:
- first -> init : converts the first element to the initial accumulator
- acc, elem -> fold : fold step; acc = current accumulator, elem = next element
- Empty iterable produces nothing (0-element splice)
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
After a {expr} or {..expr} placeholder, an optional chain of
.<builtin>() calls may follow. Currently the only builtin is:
.map(param -> template)
which applies the template to each element of the iterable and
collects the resulting node IDs. A chain auto-splices into the
enclosing field/child position.
Example:
path: {parts}.map(p -> (identifier #{p}))
The framework is extensible: additional builtins can be added by
matching on the method name in parse_chain_suffix.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
