View Source Quokka.Style behaviour (Quokka v2.4.1)
A Style takes AST and returns a transformed version of that AST.
Because these transformations involve traversing trees (the "T" in "AST"), we wrap the AST in a structure called a Zipper to facilitate walking the trees.
Summary
Callbacks
run will be used with Zipper.traverse_while/3, meaning it will be executed on every node of the AST.
Functions
Gets all comments in range start_line..last_line, and any comments immediately before start_line.s
Returns all comments "for" a node, including on the line before it.
see comments_for_lines for more
Set the line of all comments with line in range_start..range_end to instead have line range_start
Returns the current node (wrapped in a __block__ if necessary) if it's a valid place to insert additional nodes
Returns a zipper focused on the nearest node where additional nodes can be inserted (a "block").
Takes a list of nodes and clumps them up, setting end_of_expression: [newlines: x] to 1 for all but the final node,
which gets 2 instead, (hopefully!) creating an empty line before whatever follows.
Recursively sets :line meta to line. Deletes :newlines unless delete_lines: false is passed
Perform a series of shifts in a single pass.
Change the line of all comments with line in range by adding delta to it.
A positive delta will move the lines further down a file, while a negative delta will move them up.
Recursively updates :line meta by adding delta
Traverses an ast node, updating all nodes' meta with meta_fun
prewalks ast and sets all meta to nil. useful for comparing AST without meta (line numbers, etc) interfering
Types
Callbacks
@callback run(Quokka.Zipper.t(), context()) :: {Quokka.Zipper.command(), Quokka.Zipper.t(), context()}
run will be used with Zipper.traverse_while/3, meaning it will be executed on every node of the AST.
You can skip traversing parts of the tree by returning a Zipper that's further along in the traversal, for example
by calling Zipper.skip(zipper) to skip an entire subtree you know is of no interest to your Style.
Functions
Gets all comments in range start_line..last_line, and any comments immediately before start_line.s
- code
a
b
- code # c
d
- code
e
here, comments_for_lines(comments, 4, 6) is "a", "b", "c", "d"
Returns all comments "for" a node, including on the line before it.
see comments_for_lines for more
Set the line of all comments with line in range_start..range_end to instead have line range_start
@spec ensure_block_parent(Quokka.Zipper.t()) :: {:ok, Quokka.Zipper.t()} | :error
Returns the current node (wrapped in a __block__ if necessary) if it's a valid place to insert additional nodes
@spec find_nearest_block(Quokka.Zipper.t()) :: Quokka.Zipper.t()
Returns a zipper focused on the nearest node where additional nodes can be inserted (a "block").
The nearest node is either the current node, an ancestor, or one of those two but wrapped in a new :__block__ node.
Takes a list of nodes and clumps them up, setting end_of_expression: [newlines: x] to 1 for all but the final node,
which gets 2 instead, (hopefully!) creating an empty line before whatever follows.
Recursively sets :line meta to line. Deletes :newlines unless delete_lines: false is passed
Perform a series of shifts in a single pass.
When shifting comments from block A to block B, naively using two passes of shift_comments/3 would result
in all comments ending up in either region A or region B (because A would move to B, then all B back to A)
This function exists to make sure that a comment is only moved once during the swap.
Change the line of all comments with line in range by adding delta to it.
A positive delta will move the lines further down a file, while a negative delta will move them up.
Recursively updates :line meta by adding delta
Traverses an ast node, updating all nodes' meta with meta_fun
prewalks ast and sets all meta to nil. useful for comparing AST without meta (line numbers, etc) interfering