# Source code

Code, stack traces, file paths and log lines break the assumptions of a prose analyzer: it splits
`std::vector` and `a.b.c` apart and keeps `getHTTPResponse` as one word nobody types. The `code`
analyzer keeps `getHTTPResponse_v2`, `std::vector`, `a.b.c`, `foo-bar`, `0xFF` and `1.2.3`
together as tokens and also indexes their parts, so the whole identifier and each word in it
match: `getHTTPResponse` finds the document, and so do `http` and `response`.

```json
{"fields": {"source": {"type": "text", "analyzer": "code"}}}
```

The chain is the `code` tokenizer, `code_split` and `lowercase`.

## Components

| Component | Kind | Does |
|---|---|---|
| `code` | tokenizer | Splits on whitespace, brackets, `/`, `\`, `=` and other punctuation, keeping identifiers, dotted and `::` paths, kebab-case names, numbers, hex and versions whole. A path or URL gives one token per component. Param `keep_operators` (default `false`) also emits operators such as `==` and `->`. |
| `code_split` | filter | Splits a token on `_ - . : $`, camelCase and letter/digit changes: `HTTPServer2Go` gives `HTTP`, `Server`, `2`, `Go`. |

`code_split` params:

| Param | Default | Meaning |
|---|---|---|
| `preserve_original` | `true` | Also keep the whole token. |
| `split_on_numerics` | `true` | Split where letters and digits meet. |
| `min_part_length` | `1` | Drop split-off parts shorter than this. |
| `stack_parts` | `false` | Put every part at the whole token's position. By default the parts follow one another, so a phrase query such as `"http response"` matches `getHTTPResponse`. |

For example, to index operators and drop one-letter parts:

```json
{
  "type": "text",
  "analyzer": {
    "tokenizer": {"name": "code", "params": {"keep_operators": true}},
    "filters": [{"name": "code_split", "params": {"min_part_length": 2}}, "lowercase"]
  }
}
```

## Notes

- The tokenizer is not a lexer: strings and comments are split the same way as code.
- `code_split` does not run on prefix, wildcard and fuzzy terms, so `getHttp*` matches whole
  identifiers that start with `gethttp`, after lowercasing.
- For Windows command lines, executable paths and registry keys, the
  [`cmdline`](command-line-search.md) analyzer splits on more punctuation and handles switches.
  For exact substrings of long values, see [Substring search](substring-search.md).
- `code` works as an analyzer name in an Elasticsearch or OpenSearch mapping too.