hakorune/tools/hako_check/rules/rule_static_top_assign.hako

using selfhost.shared.common.string_helpers as Str

static box RuleStaticTopAssignBox {
  apply(text, path, out) {
    local n = Str.len(text); local line = 1
    local in_static = 0; local brace = 0; local in_method = 0
    local i = 0
    while i < n {
      local c = text.substring(i, i+1)
      if c == "\n" { line = line + 1 }
      if in_static == 0 {
        if me._match_kw(text, i, "static box ") { in_static = 1; in_method = 0 }
      }
      if in_static == 1 {
        if in_method == 0 && me._match_kw(text, i, "method ") { in_method = 1 }
        if c == "{" { brace = brace + 1 }
        if c == "}" { brace = brace - 1; if brace <= 0 { in_static = 0; in_method = 0 } }
        if in_method == 0 {
          if me._is_line_head(text, i) == 1 {
            if me._is_ident_start(c) == 1 {
              // find '=' before EOL
              local seen_eq = 0
              do { local off = 0; while off < n {
                local j = i + 1 + off
                if j >= n { break }
                local cj = text.substring(j, j+1)
                if cj == "\n" { break }
                if cj == "=" { seen_eq = 1; break }
                off = off + 1 } } while 0
              if seen_eq == 1 {
                out.push("[HC001] top-level assignment in static box (use lazy init in method): " + path + ":" + Str.int_to_str(line))
              }
            }
          }
        }
      }
      i = i + 1
    }
  }
  _match_kw(s,i,kw) { local k=Str.len(kw); if i+k>Str.len(s) { return 0 }; if s.substring(i,i+k)==kw { return 1 } return 0 }
  _is_ident_start(c) { if c=="_" {return 1}; if c>="A"&&c<="Z" {return 1}; if c>="a"&&c<="z" {return 1}; return 0 }
  _is_line_head(s,i) {
    local r = 0
    while r <= i {
      if i==0 {return 1}
      local j=i-1-r
      local cj=s.substring(j,j+1)
      if cj=="\n" {return 1}
      if cj!=" "&&cj!="\t" {return 0}
      if j==0 {return 1}
      r = r + 1
    }
    return 1
  }
}

static box RuleStaticTopAssignMain { method main(args) { return 0 } }