Module tree_sitter_graph::reference::functions

This section defines the standard library of functions available to graph DSL files.

Note that the process that is executing the graph DSL file has control over which function it provides. Most of the time, you will have (at least) the functions defined here available. There might be additional functions available, and in rare cases, there might be a completely different set of functions available!

General functions

eq

Check if values are equal.

• Input parameters: two values
• Output value: a boolean indicating whether the values are equal or not

The compared values must be of the same type. Null values are equal to each other and can be compared to values of any type.

is-null

Check if an optional value is missing.

• Input parameters: one value
• Output value: a boolean indicating whether the value is null or not

Graph manipulation functions

node

Creates a new graph node.

• Input parameters: none
• Output value: a reference to the new graph node

Logical functions

not

Negates a boolean value.

• Input parameters: one boolean
• Output value: the negation of the input value

and

Computes the conjunction of boolean values: true if none of the inputs are false, otherwise false.

• Input parameters: zero or more booleans
• Output value: the conjunction of all the input booleans

or

Computes the disjunction of boolean values: true if any of the inputs are true, otherwise false.

• Input parameters: zero or more booleans
• Output value: the disjunction of all the input booleans

Mathematical functions

plus

Adds integers together.

• Input parameters: zero or more integers
• Output value: the sum of all of the input integers

String functions

format

Formats a string according to the given format string and arguments.

• Input parameters:

  • format: a format string containing placeholders
  • as many additional parameters as there are placeholders in the format string

• Output value: a formatted string with the placeholders replaced by formatted values

Placeholders are written as {}. To produce literal braces, use {{ and }} instead.

replace

Applies a regular expression to a string, replacing any text that matches.

• Input parameters:
  • text: a string to look for matches in
  • pattern: a string defining the regular expression to search for
  • replacement: the text to replace any matches with

Note that the regular expression syntax that we support is exactly that used by Rust’s regex crate. In particular, the pattern is passed in to Regex::new, and the replacement text passed in to Regex::replace_all.

List functions

concat

Concatenate list arguments.

• Input parameters: list values
• Output value: the concatenation of the input lists

is-empty

Test whether a list is empty or not.

• Input parameters: a list value
• Output value: a boolean indicating whether the list is empty or not

join

Join a list of values using the given separator

• Input parameters:
  • list: A list of values
  • sep: An optional separator string
• Output value:
  • A string consisting of the formatted values from the list separated by the separator string

length

Determine the length of a list.

• Input parameters: a list value
• Output value: an integer indicating the length of the list

Syntax manipulation functions

named-child-index

Returns the index of a “named child” within its parent.

• Input parameters:
  • node: A syntax node
• Output value:
  • The index of node within its parent’s list of named children (i.e., the index that would cause ts_node_named_child to return node)

named-child-count

Returns the number of “named children” of a syntax node.

• Input parameters:
  • node: A syntax node
• Output value:
  • The number of named children in node

source-text

Returns the source text represented by a syntax node.

• Input parameters:
  • node: A syntax node
• Output value:
  • A string containing the source text represented by node

node-type

Returns a syntax node’s type as a string. (The type is the name of the node’s grammar rule in the underlying tree-sitter grammar.)

• Input parameters:
  • node: A syntax node
• Output value:
  • A string containing the type of node

start-column

Returns the zero-based start column of a syntax node.

• Input parameters:
  • node: A syntax node
• Output value:
  • The zero-based start column of node

start-row

Returns the zero-based start row of a syntax node.

• Input parameters:
  • node: A syntax node
• Output value:
  • The zero-based start row of node

end-column

Returns the zero-based end column of a syntax node.

• Input parameters:
  • node: A syntax node
• Output value:
  • The zero-based end column of node

end-row

Returns the zero-based end row of a syntax node.

• Input parameters:
  • node: A syntax node
• Output value:
  • The zero-based end row of node