pattern_rule: Build a pattern rule

In astgrepr: Parse and Manipulate R Code

Build a pattern rule

Description

This is a specific type of rule. It can be used in the more general ruleset built with ast_rule().

Usage

pattern_rule(selector = NULL, context = NULL, strictness = "smart")

Arguments

selector	Defines the surrounding code that helps to resolve any ambiguity in the syntax.
context	Defines the sub-syntax node kind that is the actual matcher of the pattern.
strictness	Optional, defines how strictly pattern will match against nodes. See 'Details'.

Details

The strictness parameter defines the type of nodes the ast-grep matcher should consider. It has the following values:

• cst: All nodes in the pattern and target code must be matched. No node is skipped.

• smart: All nodes in the pattern must be matched, but it will skip unnamed nodes in target code. This is the default behavior.

• ast: Only named AST nodes in both pattern and target code are matched. All unnamed nodes are skipped.

• relaxed: Named AST nodes in both pattern and target code are matched. Comments and unnamed nodes are ignored.

• signature: Only named AST nodes' kinds are matched. Comments, unnamed nodes and text are ignored.

More information: https://ast-grep.github.io/guide/rule-config/atomic-rule.html#pattern-object

Value

An list of class astgrep_pattern_rule

astgrepr documentation built on June 8, 2025, 11:05 a.m.