How to implement "array type" grammar like typescript with pegjs?

Question

my problem is in the implementation of "array type" like typescript.

according to my grammar. In "array type" you can use "[]" after any type (eg string or int or even array again like int[][]).

this is simplified version of my grammar:

start = type

type = array / bool / string / int

string = "string"
int = "int"
bool = "bool"

// problem
array = t:type "[]" { return { kind: "array",type: t }}

the above code throw an syntax error:

Error: Maximum call stack size exceeded

_When_ do you get the error? When the _grammar_ is parsed? When you try an parse something _with_ it? Some other time? — Darryl Noakes, Mar 02 '23 at 17:57

MfyDev · Answer 1 · 2023-07-21T14:26:00.160

0

Your grammar type can call array, array can call type again, and so on. You need to create a new type rule that contains array as last case so that it won't loop:

start = type

primitive = bool / string / int
type = primitive / array

string = "string"
int = "int"
bool = "bool"

array = t:type "[]" { return { kind: "array",type: t }}

edited Jul 21 '23 at 14:26

answered Jul 21 '23 at 13:15

MfyDev

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1
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Except that an array can be an array of arrays, so this doesn't work. The issue is how to create a recursive rule in pegjs. – Darryl Noakes Jul 21 '23 at 14:11
@DarrylNoakes Edited. It should work recursively now. – MfyDev Jul 22 '23 at 17:47

How to implement "array type" grammar like typescript with pegjs?

1 Answers1