Crashes because of wrong recursive generics resolution of a struct reference in V

crash-ref.vsh

#!/usr/bin/env -S v run

// import json
// import os
import v.reflection { get_type }

// Declare structures covering a subset of a HAR file

struct HarContent {
	size      i64
	mime_type string @[json: 'mimeType']
}

struct HarResponse {
	content HarContent
}

struct HarEntry {
	response HarResponse
}

pub struct HarLog {
	entries []HarEntry
}

struct Har {
	log HarLog
}

// Declare function printing object contents using generics

fn show[T](val T) {
	$if T is string {
		show_string(val)
	} $else $if T is $array {
		show_array(val)
	} $else $if T is $struct {
		show_struct(&val)
	} $else {
		print('primitive: ${val.str()}')
	}
}

fn show_array[T](array []T) {
	println('array []${T.name}')
	for i, item in array {
		println('item ${i}')
		show(item)
		println('')
	}
}

fn show_struct[T](object &T) {
	println('struct ${T.name}')
	$for field in T.fields {
		mut json_name := field.name
		for attr in field.attrs {
			if attr.starts_with('json: ') {
				json_name = attr[6..]
			}
		}

		print('key: ')
		show_string(json_name)
		println('')

		println('value ${T.name}.${field.name} (json: ${json_name}) of type ${type_name(field.typ)}')
		$if field.typ is string {
			print('string: ')
			show_string(object.$(field.name))
		} $else $if field.is_array {
			show_array(object.$(field.name))
		} $else $if field.is_struct {
			item := object.$(field.name)
			show_struct(&item)
		} $else {
			print('primitive: ')
			print(object.$(field.name).str())
		}
		println('')
	}
}

fn show_string(s string) {
	print(`"`)
	print(s)
	print(`"`)
}

fn type_name(idx int) string {
	if typ := get_type(idx) {
		return typ.name
	}
	panic('unknown type ${idx}')
}

// Read a HAR file and deserialise it using the built-in json support
// raw := os.read_file('har.json')!
// har := json.decode(Har, raw)!

// Simulate a HAR deserialised from a JSON file

har := Har{
  log: HarLog{
    entries: [
      HarEntry{
        response: HarResponse{
          content: HarContent{
            size: 48752,
            mime_type: "text/html"
          }
        }
      }
    ]
  }
}

// Show the deserialised object - crashes in generics

show(har)

fail-mut.vsh

#!/usr/bin/env -S v run

// import json
// import os
import v.reflection { get_type }

// Declare structures covering a subset of a HAR file

struct HarContent {
	size      i64
	mime_type string @[json: 'mimeType']
}

struct HarResponse {
	content HarContent
}

struct HarEntry {
	response HarResponse
}

pub struct HarLog {
	entries []HarEntry
}

struct Har {
	log HarLog
}

// Declare function printing object contents using generics

fn show[T](mut val T) {
	$if T is string {
		show_string(val)
	} $else $if T is $array {
		show_array(mut val)
	} $else $if T is $struct {
		show_struct(mut val)
	} $else {
		print('primitive: ${val.str()}')
	}
}

fn show_array[T](mut array []T) {
	println('array []${T.name}')
	for i, mut item in array {
		println('item ${i}')
		show(mut item)
		println('')
	}
}

fn show_struct[T](mut object T) {
	println('struct ${T.name}')
	$for field in T.fields {
		mut json_name := field.name
		for attr in field.attrs {
			if attr.starts_with('json: ') {
				json_name = attr[6..]
			}
		}

		print('key: ')
		show_string(json_name)
		println('')

		println('value ${T.name}.${field.name} (json: ${json_name}) of type ${type_name(field.typ)}')
		$if field.typ is string {
			print('string: ')
			show_string(object.$(field.name))
		} $else $if field.is_array {
			show_array(mut object.$(field.name))
		} $else $if field.is_struct {
			show_struct(mut object.$(field.name))
		} $else {
			print('primitive: ')
			print(object.$(field.name).str())
		}
		println('')
	}
}

fn show_string(s string) {
	print(`"`)
	print(s)
	print(`"`)
}

fn type_name(idx int) string {
	if typ := get_type(idx) {
		return typ.name
	}
	panic('unknown type ${idx}')
}

// Read a HAR file and deserialise it using the built-in json support
// raw := os.read_file('har.json')!
// har := json.decode(Har, raw)!

// Simulate a HAR deserialised from a JSON file

mut har := Har{
  log: HarLog{
    entries: [
      HarEntry{
        response: HarResponse{
          content: HarContent{
            size: 48752,
            mime_type: "text/html"
          }
        }
      }
    ]
  }
}

// Show the deserialised object

show(mut har)

har.json

{
  "log": {
    "entries": [
      {
        "response": {
          "content": {
            "size": 48752,
            "mimeType": "text/html"
          }
        }
      }
    ]
  }
}

succeed-value.vsh

#!/usr/bin/env -S v run

// import json
// import os
import v.reflection { get_type }

// Declare structures covering a subset of a HAR file

struct HarContent {
	size      i64
	mime_type string @[json: 'mimeType']
}

struct HarResponse {
	content HarContent
}

struct HarEntry {
	response HarResponse
}

pub struct HarLog {
	entries []HarEntry
}

struct Har {
	log HarLog
}

// Declare function printing object contents using generics

fn show[T](val T) {
	$if T is string {
		show_string(val)
	} $else $if T is $array {
		show_array(val)
	} $else $if T is $struct {
		show_struct(val)
	} $else {
		print('primitive: ${val.str()}')
	}
}

fn show_array[T](array []T) {
	println('array []${T.name}')
	for i, item in array {
		println('item ${i}')
		show(item)
		println('')
	}
}

fn show_struct[T](object T) {
	println('struct ${T.name}')
	$for field in T.fields {
		mut json_name := field.name
		for attr in field.attrs {
			if attr.starts_with('json: ') {
				json_name = attr[6..]
			}
		}

		print('key: ')
		show_string(json_name)
		println('')

		println('value ${T.name}.${field.name} (json: ${json_name}) of type ${type_name(field.typ)}')
		$if field.typ is string {
			print('string: ')
			show_string(object.$(field.name))
		} $else $if field.is_array {
			show_array(object.$(field.name))
		} $else $if field.is_struct {
			show_struct(object.$(field.name))
		} $else {
			print('primitive: ')
			print(object.$(field.name).str())
		}
		println('')
	}
}

fn show_string(s string) {
	print(`"`)
	print(s)
	print(`"`)
}

fn type_name(idx int) string {
	if typ := get_type(idx) {
		return typ.name
	}
	panic('unknown type ${idx}')
}

// Read a HAR file and deserialise it using the built-in json support
// raw := os.read_file('har.json')!
// har := json.decode(Har, raw)!

// Simulate a HAR deserialised from a JSON file

har := Har{
  log: HarLog{
    entries: [
      HarEntry{
        response: HarResponse{
          content: HarContent{
            size: 48752,
            mime_type: "text/html"
          }
        }
      }
    ]
  }
}

// Show the deserialised object

show(har)