fix digit escape in highlight regex for constants

[the-mikedavis]

Checklist (:heavy_check_mark:)

• All tests pass in CI.
• There are sufficient tests for the new fix/feature. (added one 👍)
• Grammar rules have not been renamed unless absolutely necessary. (N/A)
• The conflicts section hasn't grown too much. (N/A)
• The parser size hasn't grown too much (check the value of STATE_COUNT in src/parser.c). (N/A)

I believe this regex escape "\d" actually needs to be "\\d" to become the digit escape.

pies.java

enum Pies {
  APPLE,
  PUMPKIN,
  PI_314
}

query1.scm

((identifier) @constant
 (#match? @constant "^_*[A-Z][A-Z\d_]+"))

query2.scm

((identifier) @constant
 (#match? @constant "^_*[A-Z][A-Z\d_]+$"))

query3.scm

((identifier) @constant
 (#match? @constant "^_*[A-Z][A-Z\\d_]+$"))

reproduction

$ tree-sitter query query1.scm pies.java
pies.java
  pattern: 0
    capture: constant, start: (1, 2), text: "APPLE"
  pattern: 0
    capture: constant, start: (2, 2), text: "PUMPKIN"
  pattern: 0
    capture: constant, start: (3, 2), text: "PI_314"

$ tree-sitter query query2.scm pies.java
pies.java
  pattern: 0
    capture: constant, start: (1, 2), text: "APPLE"
  pattern: 0
    capture: constant, start: (2, 2), text: "PUMPKIN"

$ tree-sitter query query3.scm pies.java
pies.java
  pattern: 0
    capture: constant, start: (1, 2), text: "APPLE"
  pattern: 0
    capture: constant, start: (2, 2), text: "PUMPKIN"
  pattern: 0
    capture: constant, start: (3, 2), text: "PI_314"

query1.scm is the current query rule, and it works but only because it doesn't end in $, so in theory other characters could end up matching the query than digits. query2.scm shows that the \d escape doesn't work: it fails to match the constant with digits. query3.scm switches to \\d with the trailing $ and it works again!

It looks like there's one of these \ds in the php queries (pr incoming...) but elsewhere there're \\ds (e.g. this ruby query)

[maxbrunsfeld]

Thanks!