code: func (p *parser) parseHashSegment() *ast.HashPair {
  	// ID
  	tok := p.shift()
  
  	// EQUALS
  	p.shift()
  
  	// param
  	param := p.parseParam()
  
  	result := ast.NewHashPair(tok.Pos, tok.Line)
  	result.Key = tok.Val
  	result.Val = param
  
  	return result
  }
docs: // hashSegment : ID EQUALS param