CSS-like AST selector builder.
Selectors are built from a starting pattern and relationship steps:
import ExAST.Selector
pattern("defmodule _ do ... end")
|> descendant("def _ do ... end")
|> child("IO.inspect(_)")The final step is the selected node. Use where/2 with predicates such as
has_child/1, has_descendant/1, parent/1, and ancestor/1 to filter the
selected node without changing it.
pattern("def _ do ... end")
|> where(has_descendant("Repo.transaction(_)"))
|> where(not(has_descendant("IO.inspect(_)")))where/2 also accepts quoted boolean predicate expressions, so you can use
Kernel.not/1 without excluding it from imports:
pattern("def _ do ... end")
|> where(not has_descendant("IO.inspect(_)"))Summary
Functions
Matches when all nested predicates match.
Builds or applies a semantic ancestor predicate.
Matches when any nested predicate matches.
Selects direct semantic children matching pattern.
SQL-like alias for has_descendant/1 and has_descendant/2.
Selects semantic descendants matching pattern.
SQL-like alias for descendant/2.
SQL-like alias for child/2.
Matches the first semantic child in its parent.
Matches when a previous sibling matches pattern.
SQL-like alias for pattern/1.
Alias for has_descendant/1 and has_descendant/2.
Builds or applies a direct semantic child predicate.
Builds or applies a semantic descendant predicate.
Matches when the immediately previous sibling matches pattern.
Matches when the immediately following sibling matches pattern.
SQL-like alias for ancestor/1 and ancestor/2.
Matches the last semantic child in its parent.
Negates a predicate for use with where/2.
Matches the nth semantic child in its parent, using 1-based indexing.
Builds or applies a direct semantic parent predicate.
Starts a selector at pattern.
Matches when a following sibling matches pattern.
Alias for pattern/1.
Adds a predicate filter without changing the selected node.
Types
@type relation() :: :self | :child | :descendant
@type step() :: {relation(), ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]}
@type t() :: %ExAST.Selector{filters: [ExAST.Selector.Predicate.t()], steps: [step()]}
Functions
@spec all([ExAST.Selector.Predicate.t()]) :: ExAST.Selector.Predicate.t()
Matches when all nested predicates match.
@spec ancestor(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Builds or applies a semantic ancestor predicate.
@spec ancestor(t(), ExAST.Pattern.pattern()) :: t()
@spec any([ExAST.Selector.Predicate.t()]) :: ExAST.Selector.Predicate.t()
Matches when any nested predicate matches.
@spec child(t(), ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
Selects direct semantic children matching pattern.
@spec contains(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
SQL-like alias for has_descendant/1 and has_descendant/2.
@spec contains(t(), ExAST.Pattern.pattern()) :: t()
@spec descendant(t(), ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
Selects semantic descendants matching pattern.
@spec find(t(), ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
SQL-like alias for descendant/2.
@spec find_child(t(), ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
SQL-like alias for child/2.
@spec first() :: ExAST.Selector.Predicate.t()
Matches the first semantic child in its parent.
@spec follows(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Matches when a previous sibling matches pattern.
@spec from(ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
SQL-like alias for pattern/1.
@spec has(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Alias for has_descendant/1 and has_descendant/2.
@spec has(t(), ExAST.Pattern.pattern()) :: t()
@spec has_child(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Builds or applies a direct semantic child predicate.
@spec has_child(t(), ExAST.Pattern.pattern()) :: t()
@spec has_descendant(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Builds or applies a semantic descendant predicate.
@spec has_descendant(t(), ExAST.Pattern.pattern()) :: t()
@spec immediately_follows(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Matches when the immediately previous sibling matches pattern.
@spec immediately_precedes(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Matches when the immediately following sibling matches pattern.
@spec inside(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
SQL-like alias for ancestor/1 and ancestor/2.
@spec inside(t(), ExAST.Pattern.pattern()) :: t()
@spec last() :: ExAST.Selector.Predicate.t()
Matches the last semantic child in its parent.
@spec not ExAST.Selector.Predicate.t() :: ExAST.Selector.Predicate.t()
Negates a predicate for use with where/2.
@spec nth(pos_integer()) :: ExAST.Selector.Predicate.t()
Matches the nth semantic child in its parent, using 1-based indexing.
@spec parent(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Builds or applies a direct semantic parent predicate.
@spec parent(t(), ExAST.Pattern.pattern()) :: t()
@spec pattern(ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
Starts a selector at pattern.
@spec precedes(ExAST.Pattern.pattern()) :: ExAST.Selector.Predicate.t()
Matches when a following sibling matches pattern.
@spec selector(ExAST.Pattern.pattern() | [ExAST.Pattern.pattern()]) :: t()
Alias for pattern/1.
Adds a predicate filter without changing the selected node.