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   1# Reference: languages coloured
3> Neutral description of which files Turbo Go colours, how it decides, and what each scanner recognises.
5## Recognition
7A file's **extension** decides whenever it is one of these:
Extension | Language |
--- | --- |
`.go` | Go |
`.toml` | TOML |
`.yaml`, `.yml` | YAML |
`.md`, `.markdown` | Markdown |
`.js`, `.mjs`, `.cjs` | JavaScript |
`.html`, `.htm` | HTML |
`.xml`, `.xsd`, `.xsl`, `.xslt`, `.svg`, `.plist`, `.csproj`, `.pom` | XML |
`.sh`, `.bash`, `.zsh` | Shell |
`.dockerfile`, `.containerfile` | Dockerfile |
21Extensions are matched case-insensitively, and only the last one counts: `main.go.backup` is not Go.
23A file whose extension decides nothing is looked up by **name** next. Only files that carry no useful extension need this:
Name | Language |
--- | --- |
`Dockerfile`, `Containerfile` | Dockerfile |
29A name matches on the whole of it or on the part before the first dot, ignoring case — so `Dockerfile`, `dockerfile` and `Dockerfile.dev` are all recognised, while `Dockerfile.md` is Markdown, because the extension is consulted first.
31A file that neither table claims is a **shell script** when its first line is a shebang naming a shell — `sh`, `bash`, `zsh`, `dash` or `ksh`, as a path element or as the argument to `env`. That is what colours `configure`, a git hook, or a script somebody renamed.
First line | Result |
--- | --- |
`#!/bin/sh` | Shell |
`#!/usr/bin/env bash` | Shell |
`#!/usr/bin/env -S bash -e` | Shell |
`#!/usr/bin/env python3` | Not coloured |
Anything not starting `#!` | Not coloured |
41The order is fixed — extension, then name, then first line — and the first to decide wins: a `.go` file starting with a shebang is Go.
43Everything else is shown in plain text. That is not an error — opening a PNG in the editor is not a mistake, it is just not coloured.
45
47Every scanner produces the same vocabulary of classes, and each maps to one theme key.
Class | Theme key | Produced by |
--- | --- | --- |
`identifier` | `syntax.identifier` | Go, TOML, JavaScript, shell, YAML, Dockerfile |
`keyword` | `syntax.keyword` | Go, JavaScript, shell, HTML (doctype), XML, Dockerfile |
`type` | `syntax.type` | Go, TOML (table headers), YAML (tags) |
`builtin` | `syntax.builtin` | Go, JavaScript, shell (builtins and expansions), YAML (anchors and aliases), Dockerfile (variables) |
`constant` | `syntax.constant` | Go, TOML, JavaScript, shell, YAML, HTML and XML (entities) |
`function` | `syntax.function` | Go, JavaScript, shell (the command) |
`string` | `syntax.string` | all |
`char` | `syntax.char` | Go |
`number` | `syntax.number` | Go, TOML, JavaScript, shell, YAML, Dockerfile |
`comment` | `syntax.comment` | Go, TOML, JavaScript, shell, HTML, YAML, XML, Dockerfile |
`operator` | `syntax.operator` | Go, TOML, JavaScript, shell, HTML, YAML (block scalar headers), XML, Dockerfile |
`punctuation` | `syntax.punctuation` | Go, TOML, JavaScript, shell, Markdown, YAML, Dockerfile |
`heading` | `syntax.heading` | Markdown |
`tag` | `syntax.tag` | HTML, XML |
`attribute` | `syntax.attribute` | HTML, XML, Dockerfile (flags) |
`emphasis` | `syntax.emphasis` | Markdown |
`link` | `syntax.link` | Markdown |
71Tokenised by `go/scanner`, the lexer the Go toolchain itself uses. See [Colouring and completion](../explanation/colouring-and-completion.md).
Recognised | As |
--- | --- |
`# comment` | comment |
`[table]`, `[[array]]` | the name as a type, the brackets as punctuation |
`key =` | identifier, then operator |
`"basic"`, `'literal'`, `"""multi-line"""`, `'''multi-line'''` | string |
`true`, `false` | constant |
numbers, dates, times, `inf`, `nan` | number |
86A compose file, a Kubernetes manifest and a CI workflow are all this: there is no separate dialect, because a dialect would be somebody else's schema to keep in step with.
Recognised | As |
--- | --- |
`# comment` | comment |
`key:` before a space or the end of the line | the key as an identifier, the colon as punctuation |
`"quoted": 1`, `'quoted': 1` | the quoted key as an identifier |
`- ` opening a sequence entry | punctuation |
`"…"`, `'…'` | string |
`true`, `false`, `yes`, `no`, `on`, `off`, `null` | constant, whatever their case |
numbers, dates and times written without quotes | number |
`&anchor`, `*alias` | builtin |
`!!str`, `!Custom` | type |
`---`, `...` | the whole line as punctuation |
`{`, `}`, `[`, `]`, `,` | punctuation |
`\|`, `>`, with their chomping and indentation indicators | the header as an operator, the body as a string |
103**A colon is a separator only when a space or the end of the line follows it.** `image: nginx:1.27` is a key and one value, and `url: http://example.com/x` is a key and one URL — colouring the inner colons as separators would put every image tag and every URL in three colours.
105**A block scalar's extent is decided by indentation**, not by a delimiter. The first content line after `|` or `>` fixes the block's indentation; every line indented at least that far belongs to it, and the first line that is not ends it. **A blank line inside a block stays inside it**: a literal scalar keeps its empty lines, and ending the block at the first paragraph break would cut a shell script in a CI file in half.
107**A `#` needs a space before it to start a comment**, so `colour: ff#00aa` is one scalar.
Not recognised | Because |
--- | --- |
The schema of a compose file, a manifest or a workflow | Colouring `services:` differently from any other key means carrying somebody else's schema, and it goes stale the day they add a key |
Multi-document streams as separate documents | `---` is coloured, but nothing is reset at it; nothing in the colouring depends on document boundaries |
Whether a bare word is a string or a number to a parser | `1.2.3` is a version to a reader and a string to YAML; the scanner colours what it looks like |
115## Markdown
Recognised | As |
--- | --- |
`# Heading` … `###### Heading` | the whole line as a heading |
`**bold**`, `__bold__`, `*italic*`, `_italic_` | emphasis |
`` `code` `` | string |
`[text](target)`, `![alt](src)` | the whole thing as a link |
`- `, `* `, `+ `, `1. `, `1) ` | the marker as punctuation |
`>` | punctuation |
`---`, `***`, `___` | punctuation |
` ``` ` and `~~~` fences | the whole block, opening and closing lines included, as a string |
128A fenced block is **one colour whatever language it announces**: ```` ```go ```` does not colour its contents as Go. The run of markers that opens a block must be matched by the same character to close it, so a backtick fence is not closed by a tilde one. An unclosed fence colours to the end of the file.
130The run of markers opening emphasis must be matched by a run of the same length, so `**bold**` is one span rather than two italics.
132## JavaScript
Recognised | As |
--- | --- |
`const`, `let`, `function`, `class`, `async`, `await`, `import`, `export`, … | keyword |
`true`, `false`, `null`, `undefined`, `NaN`, `Infinity`, `this` | constant |
`console`, `document`, `window`, `Array`, `Object`, `Promise`, `Math`, `JSON`, … | builtin |
a name immediately before `(` | function |
`"…"`, `'…'` | string |
`` `…` ``, interpolations included, across lines | string |
`//` to end of line, `/* … */` across lines | comment |
`42`, `3.14`, `0x1f`, `0b1010`, `0o777`, `1_000_000`, `1e6`, `10n` | number |
runs of `+-*/%=<>!&|^~?:` | operator |
`()[]{},;.` | punctuation |
147**Regular-expression literals are not recognised.** Telling `/x/g` from a division needs to know whether the previous token could end an expression; a wrong guess colours the rest of a line as a string, which is worse than leaving a regex the colour of an operator.
149Globals are recognised by name, so a file that shadows `Math` still has it coloured as a builtin — the same rule Go's predeclared identifiers follow.
Recognised | As |
--- | --- |
`<tag`, `</tag`, `>`, `/>` | tag |
attribute names, including `data-*`, `xlink:href`, `@click`, `v-bind.prop` | attribute |
`=` | operator |
`"…"`, `'…'` | string |
`<!-- … -->`, across lines | comment |
`&amp;`, `&#169;` | constant |
`<!DOCTYPE …>` and other declarations | keyword |
163Text between tags is not coloured. A bare `&` with no `;` within 32 characters is left alone, because it is legal text.
165**The contents of `<script>` and `<style>` are not coloured** as JavaScript and CSS.
169Its own scanner rather than HTML's, for one reason that matters: CDATA. The whole point of `<![CDATA[ … ]]>` is that its contents are *not* markup, and colouring the tags inside one as tags is exactly backwards.
Recognised | As |
--- | --- |
`<?xml version="1.0"?>` and other processing instructions | the target and `?>` as keyword, the pairs between as attributes and strings |
`<!DOCTYPE …>` and the other `<!` forms | keyword |
`<!-- … -->`, across lines | comment |
`<![CDATA[ … ]]>`, across lines | string |
`<tag`, `</tag`, `>`, `/>` | tag |
`<ns:tag>`, `xsi:type` | the prefix and the local name as **one** span |
attribute names | attribute |
`=` | operator |
`"…"`, `'…'` | string |
`&amp;`, `&#169;` | constant |
184**A comment and a CDATA section close on different delimiters**, and are carried separately: a `-->` inside a CDATA section does not end it.
186**A bare `&` with no semicolon within 32 characters is left alone**, because it is legal text in plenty of documents and swallowing the rest of the line would be the bigger mistake.
188Text between tags is not coloured.
190
192Applies to `sh`, `bash` and `zsh` alike: the keywords recognised are the ones they share.
Recognised | As |
--- | --- |
`if`, `then`, `fi`, `for`, `while`, `case`, `esac`, `function`, `return`, … | keyword |
`true`, `false` | constant |
`echo`, `printf`, `export`, `local`, `read`, `cd`, `set`, `source`, … | builtin |
`$NAME`, `${…}`, `$(…)`, `$1`, `$?`, `$@` | builtin |
the **first bare word on a line** | function |
every later bare word, and `NAME` in `NAME=value` | identifier |
`'…'`, with nothing escaped or expanded inside | string |
`"…"`, with the expansions inside it coloured as expansions | string |
`#` to end of line | comment |
206`$(a $(b) c)` is one span: nesting is counted. An option such as `-euo` is one word, not a minus and a word.
208**Heredocs are not recognised.** `<<EOF` and the text after it are coloured as ordinary shell.
210## Dockerfile
Recognised | As |
--- | --- |
`FROM`, `RUN`, `COPY`, `ADD`, `ARG`, `ENV`, `CMD`, `ENTRYPOINT`, `EXPOSE`, `LABEL`, `USER`, `VOLUME`, `WORKDIR`, `HEALTHCHECK`, `ONBUILD`, `SHELL`, `STOPSIGNAL`, `MAINTAINER` | keyword, in any case |
`AS`, `NONE` | keyword |
`# comment`, including the `# syntax=` and `# escape=` directives | comment |
`--from=builder`, `--chown=me:me` | the flag name as an attribute |
`$NAME`, `${NAME}`, `${NAME:-default}` | builtin, as one span to the closing brace |
`"…"`, `'…'` | string |
a trailing `\` | operator |
numbers | number |
paths and image references — `/usr/local/bin`, `golang:1.26-alpine` | identifier, as **one** span |
224**Only the first word of a line can be an instruction**, and a word that is not one is an argument — which is what keeps a continuation line's first word out of the keyword colour.
226**Nothing crosses a line break.** A `\` joins two lines for Docker, but each half still reads as a command and is coloured on its own.
Not recognised | Because |
--- | --- |
The shell inside a `RUN` | It would mean running the shell scanner over part of a line and mapping its columns out, and `RUN` may hold any language |
Heredocs in a `RUN` | The same reason the shell scanner does not recognise them |
Which stage a `--from` names | Nothing here reads the rest of the file |
234## See also
236- [Theme file format](themes.md) — every key these classes resolve to
237- [Colouring and completion](../explanation/colouring-and-completion.md) — why the scanners are written this way
238- [How to write your own theme](../how-to/write-a-theme.md)

📦 Turbo Go 3d7798b k33g 12h ago	1	# Reference: languages coloured
	2
	3	> Neutral description of which files Turbo Go colours, how it decides, and what each scanner recognises.
	4
	5	## Recognition
	6
	7	A file's extension decides whenever it is one of these:
	8
	9	\| Extension \| Language \|
	10	\| --- \| --- \|
	11	\| `.go` \| Go \|
	12	\| `.toml` \| TOML \|
	13	\| `.yaml`, `.yml` \| YAML \|
	14	\| `.md`, `.markdown` \| Markdown \|
	15	\| `.js`, `.mjs`, `.cjs` \| JavaScript \|
	16	\| `.html`, `.htm` \| HTML \|
	17	\| `.xml`, `.xsd`, `.xsl`, `.xslt`, `.svg`, `.plist`, `.csproj`, `.pom` \| XML \|
	18	\| `.sh`, `.bash`, `.zsh` \| Shell \|
	19	\| `.dockerfile`, `.containerfile` \| Dockerfile \|
	20
	21	Extensions are matched case-insensitively, and only the last one counts: `main.go.backup` is not Go.
	22
	23	A file whose extension decides nothing is looked up by name next. Only files that carry no useful extension need this:
	24
	25	\| Name \| Language \|
	26	\| --- \| --- \|
	27	\| `Dockerfile`, `Containerfile` \| Dockerfile \|
	28
	29	A name matches on the whole of it or on the part before the first dot, ignoring case — so `Dockerfile`, `dockerfile` and `Dockerfile.dev` are all recognised, while `Dockerfile.md` is Markdown, because the extension is consulted first.
	30
	31	A file that neither table claims is a shell script when its first line is a shebang naming a shell — `sh`, `bash`, `zsh`, `dash` or `ksh`, as a path element or as the argument to `env`. That is what colours `configure`, a git hook, or a script somebody renamed.
	32
	33	\| First line \| Result \|
	34	\| --- \| --- \|
	35	\| `#!/bin/sh` \| Shell \|
	36	\| `#!/usr/bin/env bash` \| Shell \|
	37	\| `#!/usr/bin/env -S bash -e` \| Shell \|
	38	\| `#!/usr/bin/env python3` \| Not coloured \|
	39	\| Anything not starting `#!` \| Not coloured \|
	40
	41	The order is fixed — extension, then name, then first line — and the first to decide wins: a `.go` file starting with a shebang is Go.
	42
	43	Everything else is shown in plain text. That is not an error — opening a PNG in the editor is not a mistake, it is just not coloured.
	44
	45	## Classes
	46
	47	Every scanner produces the same vocabulary of classes, and each maps to one theme key.
	48
	49	\| Class \| Theme key \| Produced by \|
	50	\| --- \| --- \| --- \|
	51	\| `identifier` \| `syntax.identifier` \| Go, TOML, JavaScript, shell, YAML, Dockerfile \|
	52	\| `keyword` \| `syntax.keyword` \| Go, JavaScript, shell, HTML (doctype), XML, Dockerfile \|
	53	\| `type` \| `syntax.type` \| Go, TOML (table headers), YAML (tags) \|
	54	\| `builtin` \| `syntax.builtin` \| Go, JavaScript, shell (builtins and expansions), YAML (anchors and aliases), Dockerfile (variables) \|
	55	\| `constant` \| `syntax.constant` \| Go, TOML, JavaScript, shell, YAML, HTML and XML (entities) \|
	56	\| `function` \| `syntax.function` \| Go, JavaScript, shell (the command) \|
	57	\| `string` \| `syntax.string` \| all \|
	58	\| `char` \| `syntax.char` \| Go \|
	59	\| `number` \| `syntax.number` \| Go, TOML, JavaScript, shell, YAML, Dockerfile \|
	60	\| `comment` \| `syntax.comment` \| Go, TOML, JavaScript, shell, HTML, YAML, XML, Dockerfile \|
	61	\| `operator` \| `syntax.operator` \| Go, TOML, JavaScript, shell, HTML, YAML (block scalar headers), XML, Dockerfile \|
	62	\| `punctuation` \| `syntax.punctuation` \| Go, TOML, JavaScript, shell, Markdown, YAML, Dockerfile \|
	63	\| `heading` \| `syntax.heading` \| Markdown \|
	64	\| `tag` \| `syntax.tag` \| HTML, XML \|
65	\| `attribute` \| `syntax.attribute` \| HTML, XML, Dockerfile (flags) \|
66	\| `emphasis` \| `syntax.emphasis` \| Markdown \|
67	\| `link` \| `syntax.link` \| Markdown \|
68
69	## Go
70
71	Tokenised by `go/scanner`, the lexer the Go toolchain itself uses. See [Colouring and completion](../explanation/colouring-and-completion.md).
72
73	## TOML
74
75	\| Recognised \| As \|
76	\| --- \| --- \|
77	\| `# comment` \| comment \|
78	\| `[table]`, `[[array]]` \| the name as a type, the brackets as punctuation \|
79	\| `key =` \| identifier, then operator \|
80	\| `"basic"`, `'literal'`, `"""multi-line"""`, `'''multi-line'''` \| string \|
81	\| `true`, `false` \| constant \|
82	\| numbers, dates, times, `inf`, `nan` \| number \|
83
84	## YAML
85
86	A compose file, a Kubernetes manifest and a CI workflow are all this: there is no separate dialect, because a dialect would be somebody else's schema to keep in step with.
87
88	\| Recognised \| As \|
89	\| --- \| --- \|
90	\| `# comment` \| comment \|
91	\| `key:` before a space or the end of the line \| the key as an identifier, the colon as punctuation \|
92	\| `"quoted": 1`, `'quoted': 1` \| the quoted key as an identifier \|
93	\| `- ` opening a sequence entry \| punctuation \|
94	\| `"…"`, `'…'` \| string \|
95	\| `true`, `false`, `yes`, `no`, `on`, `off`, `null` \| constant, whatever their case \|
96	\| numbers, dates and times written without quotes \| number \|
97	\| `&anchor`, `*alias` \| builtin \|
98	\| `!!str`, `!Custom` \| type \|
99	\| `---`, `...` \| the whole line as punctuation \|
100	\| `{`, `}`, `[`, `]`, `,` \| punctuation \|
101	\| `\\|`, `>`, with their chomping and indentation indicators \| the header as an operator, the body as a string \|
102
103	A colon is a separator only when a space or the end of the line follows it. `image: nginx:1.27` is a key and one value, and `url: http://example.com/x` is a key and one URL — colouring the inner colons as separators would put every image tag and every URL in three colours.
104
105	A block scalar's extent is decided by indentation, not by a delimiter. The first content line after `\|` or `>` fixes the block's indentation; every line indented at least that far belongs to it, and the first line that is not ends it. A blank line inside a block stays inside it: a literal scalar keeps its empty lines, and ending the block at the first paragraph break would cut a shell script in a CI file in half.
106
107	A `#` needs a space before it to start a comment, so `colour: ff#00aa` is one scalar.
108
109	\| Not recognised \| Because \|
110	\| --- \| --- \|
111	\| The schema of a compose file, a manifest or a workflow \| Colouring `services:` differently from any other key means carrying somebody else's schema, and it goes stale the day they add a key \|
112	\| Multi-document streams as separate documents \| `---` is coloured, but nothing is reset at it; nothing in the colouring depends on document boundaries \|
113	\| Whether a bare word is a string or a number to a parser \| `1.2.3` is a version to a reader and a string to YAML; the scanner colours what it looks like \|
114
115	## Markdown
116
117	\| Recognised \| As \|
118	\| --- \| --- \|
119	\| `# Heading` … `###### Heading` \| the whole line as a heading \|
120	\| `bold`, `__bold__`, `italic`, `_italic_` \| emphasis \|
121	\| `` `code` `` \| string \|
122	\| `[text](target)`, `![alt](src)` \| the whole thing as a link \|
123	\| `- `, `* `, `+ `, `1. `, `1) ` \| the marker as punctuation \|
124	\| `>` \| punctuation \|
125	\| `---`, `***`, `___` \| punctuation \|
126	\| ` ``` ` and `~~~` fences \| the whole block, opening and closing lines included, as a string \|
127
128	A fenced block is one colour whatever language it announces: ```` ```go ```` does not colour its contents as Go. The run of markers that opens a block must be matched by the same character to close it, so a backtick fence is not closed by a tilde one. An unclosed fence colours to the end of the file.
129
130	The run of markers opening emphasis must be matched by a run of the same length, so `bold` is one span rather than two italics.
131
132	## JavaScript
133
134	\| Recognised \| As \|
135	\| --- \| --- \|
136	\| `const`, `let`, `function`, `class`, `async`, `await`, `import`, `export`, … \| keyword \|
137	\| `true`, `false`, `null`, `undefined`, `NaN`, `Infinity`, `this` \| constant \|
138	\| `console`, `document`, `window`, `Array`, `Object`, `Promise`, `Math`, `JSON`, … \| builtin \|
139	\| a name immediately before `(` \| function \|
140	\| `"…"`, `'…'` \| string \|
141	\| `` `…` ``, interpolations included, across lines \| string \|
142	\| `//` to end of line, `/* … */` across lines \| comment \|
143	\| `42`, `3.14`, `0x1f`, `0b1010`, `0o777`, `1_000_000`, `1e6`, `10n` \| number \|
144	\| runs of `+-*/%=<>!&\|^~?:` \| operator \|
145	\| `()[]{},;.` \| punctuation \|
146
147	Regular-expression literals are not recognised. Telling `/x/g` from a division needs to know whether the previous token could end an expression; a wrong guess colours the rest of a line as a string, which is worse than leaving a regex the colour of an operator.
148
149	Globals are recognised by name, so a file that shadows `Math` still has it coloured as a builtin — the same rule Go's predeclared identifiers follow.
150
151	## HTML
152
153	\| Recognised \| As \|
154	\| --- \| --- \|
155	\| `<tag`, `</tag`, `>`, `/>` \| tag \|
156	\| attribute names, including `data-*`, `xlink:href`, `@click`, `v-bind.prop` \| attribute \|
157	\| `=` \| operator \|
158	\| `"…"`, `'…'` \| string \|
159	\| `<!-- … -->`, across lines \| comment \|
160	\| `&`, `©` \| constant \|
161	\| `<!DOCTYPE …>` and other declarations \| keyword \|
162
163	Text between tags is not coloured. A bare `&` with no `;` within 32 characters is left alone, because it is legal text.
164
165	The contents of `<script>` and `<style>` are not coloured as JavaScript and CSS.
166
167	## XML
168
169	Its own scanner rather than HTML's, for one reason that matters: CDATA. The whole point of `<![CDATA[ … ]]>` is that its contents are not markup, and colouring the tags inside one as tags is exactly backwards.
170
171	\| Recognised \| As \|
172	\| --- \| --- \|
173	\| `<?xml version="1.0"?>` and other processing instructions \| the target and `?>` as keyword, the pairs between as attributes and strings \|
174	\| `<!DOCTYPE …>` and the other `<!` forms \| keyword \|
175	\| `<!-- … -->`, across lines \| comment \|
176	\| `<![CDATA[ … ]]>`, across lines \| string \|
177	\| `<tag`, `</tag`, `>`, `/>` \| tag \|
178	\| `<ns:tag>`, `xsi:type` \| the prefix and the local name as one span \|
179	\| attribute names \| attribute \|
180	\| `=` \| operator \|
181	\| `"…"`, `'…'` \| string \|
182	\| `&`, `©` \| constant \|
183
184	A comment and a CDATA section close on different delimiters, and are carried separately: a `-->` inside a CDATA section does not end it.
185
186	A bare `&` with no semicolon within 32 characters is left alone, because it is legal text in plenty of documents and swallowing the rest of the line would be the bigger mistake.
187
188	Text between tags is not coloured.
189
190	## Shell
191
192	Applies to `sh`, `bash` and `zsh` alike: the keywords recognised are the ones they share.
193
194	\| Recognised \| As \|
195	\| --- \| --- \|
196	\| `if`, `then`, `fi`, `for`, `while`, `case`, `esac`, `function`, `return`, … \| keyword \|
197	\| `true`, `false` \| constant \|
198	\| `echo`, `printf`, `export`, `local`, `read`, `cd`, `set`, `source`, … \| builtin \|
199	\| `$NAME`, `${…}`, `$(…)`, `$1`, `$?`, `$@` \| builtin \|
200	\| the first bare word on a line \| function \|
201	\| every later bare word, and `NAME` in `NAME=value` \| identifier \|
202	\| `'…'`, with nothing escaped or expanded inside \| string \|
203	\| `"…"`, with the expansions inside it coloured as expansions \| string \|
204	\| `#` to end of line \| comment \|
205
206	`$(a $(b) c)` is one span: nesting is counted. An option such as `-euo` is one word, not a minus and a word.
207
208	Heredocs are not recognised. `<<EOF` and the text after it are coloured as ordinary shell.
209
210	## Dockerfile
211
212	\| Recognised \| As \|
213	\| --- \| --- \|
214	\| `FROM`, `RUN`, `COPY`, `ADD`, `ARG`, `ENV`, `CMD`, `ENTRYPOINT`, `EXPOSE`, `LABEL`, `USER`, `VOLUME`, `WORKDIR`, `HEALTHCHECK`, `ONBUILD`, `SHELL`, `STOPSIGNAL`, `MAINTAINER` \| keyword, in any case \|
215	\| `AS`, `NONE` \| keyword \|
216	\| `# comment`, including the `# syntax=` and `# escape=` directives \| comment \|
217	\| `--from=builder`, `--chown=me:me` \| the flag name as an attribute \|
218	\| `$NAME`, `${NAME}`, `${NAME:-default}` \| builtin, as one span to the closing brace \|
219	\| `"…"`, `'…'` \| string \|
220	\| a trailing `\` \| operator \|
221	\| numbers \| number \|
222	\| paths and image references — `/usr/local/bin`, `golang:1.26-alpine` \| identifier, as one span \|
223
224	Only the first word of a line can be an instruction, and a word that is not one is an argument — which is what keeps a continuation line's first word out of the keyword colour.
225
226	Nothing crosses a line break. A `\` joins two lines for Docker, but each half still reads as a command and is coloured on its own.
227
228	\| Not recognised \| Because \|
229	\| --- \| --- \|
230	\| The shell inside a `RUN` \| It would mean running the shell scanner over part of a line and mapping its columns out, and `RUN` may hold any language \|
231	\| Heredocs in a `RUN` \| The same reason the shell scanner does not recognise them \|
232	\| Which stage a `--from` names \| Nothing here reads the rest of the file \|
233
234	## See also
235
236	- [Theme file format](themes.md) — every key these classes resolve to
237	- [Colouring and completion](../explanation/colouring-and-completion.md) — why the scanners are written this way
238	- [How to write your own theme](../how-to/write-a-theme.md)