Repository: rust-lang/mdBook (language: rust)

Issue:
Add nix-lang highlighting by default
### Problem

I'm using mdbook for a nix project and [highlightjs](https://highlightjs.readthedocs.io/en/latest/supported-languages.html) supports the nix-lang but mdbook [disables](https://rust-lang.github.io/mdBook/format/theme/syntax-highlighting.html) it by default.

### Proposed Solution

Vendor a highlight,js version with nix-lang support.

### Notes

This would probably be sensible since nix and rust is a pretty popular tooling combination and things like rustlings even have nix instructions and files by default.


Discussion / hints:

Fix patch:
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index ec8f29cded..98c31a9c78 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -148,7 +148,7 @@ The following are instructions for updating [highlight.js](https://highlightjs.o
 1. Clone the repository at <https://github.com/highlightjs/highlight.js>
 1. Check out a tagged release (like `10.1.1`).
 1. Run `npm install`
-1. Run `node tools/build.js :common apache armasm coffeescript d handlebars haskell http julia nginx nim properties r scala x86asm yaml`
+1. Run `node tools/build.js :common apache armasm coffeescript d handlebars haskell http julia nginx nim nix properties r scala x86asm yaml`
 1. Compare the language list that it spits out to the one in [`syntax-highlighting.md`](https://github.com/camelid/mdBook/blob/master/guide/src/format/theme/syntax-highlighting.md). If any are missing, add them to the list and rebuild (and update these docs). If any are added to the common set, add them to `syntax-highlighting.md`.
 1. Copy `build/highlight.min.js` to mdbook's directory [`highlight.js`](https://github.com/rust-lang/mdBook/blob/master/src/theme/highlight.js).
 1. Be sure to check the highlight.js [CHANGES](https://github.com/highlightjs/highlight.js/blob/main/CHANGES.md) for any breaking changes. Breaking changes that would affect users will need to wait until the next major release.
diff --git a/guide/src/format/theme/syntax-highlighting.md b/guide/src/format/theme/syntax-highlighting.md
index 452a650fba..df36041ca1 100644
--- a/guide/src/format/theme/syntax-highlighting.md
+++ b/guide/src/format/theme/syntax-highlighting.md
@@ -45,6 +45,7 @@ your own `highlight.js` file:
 - markdown
 - nginx
 - nim
+- nix
 - objectivec
 - perl
 - php
diff --git a/src/theme/highlight.js b/src/theme/highlight.js
index 3256c00ed3..18d24345bd 100644
--- a/src/theme/highlight.js
+++ b/src/theme/highlight.js
@@ -48,6 +48,7 @@ hljs.registerLanguage("handlebars",function(){"use strict";function e(...e){retu
 hljs.registerLanguage("haskell",function(){"use strict";return function(e){var n={variants:[e.COMMENT("--","$"),e.COMMENT("{-","-}",{contains:["self"]})]},i={className:"meta",begin:"{-#",end:"#-}"},a={className:"meta",begin:"^#",end:"$"},s={className:"type",begin:"\\b[A-Z][\\w']*",relevance:0},l={begin:"\\(",end:"\\)",illegal:'"',contains:[i,a,{className:"type",begin:"\\b[A-Z][\\w]*(\\((\\.\\.|,|\\w+)\\))?"},e.inherit(e.TITLE_MODE,{begin:"[_a-z][\\w']*"}),n]};return{name:"Haskell",aliases:["hs"],keywords:"let in if then else case of where do module import hiding qualified type data newtype deriving class instance as default infix infixl infixr foreign export ccall stdcall cplusplus jvm dotnet safe unsafe family forall mdo proc rec",contains:[{beginKeywords:"module",end:"where",keywords:"module where",contains:[l,n],illegal:"\\W\\.|;"},{begin:"\\bimport\\b",end:"$",keywords:"import qualified as hiding",contains:[l,n],illegal:"\\W\\.|;"},{className:"class",begin:"^(\\s*)?(class|instance)\\b",end:"where",keywords:"class family instance where",contains:[s,l,n]},{className:"class",begin:"\\b(data|(new)?type)\\b",end:"$",keywords:"data family type newtype deriving",contains:[i,s,l,{begin:"{",end:"}",contains:l.contains},n]},{beginKeywords:"default",end:"$",contains:[s,l,n]},{beginKeywords:"infix infixl infixr",end:"$",contains:[e.C_NUMBER_MODE,n]},{begin:"\\bforeign\\b",end:"$",keywords:"foreign import export ccall stdcall cplusplus jvm dotnet safe unsafe",contains:[s,e.QUOTE_STRING_MODE,n]},{className:"meta",begin:"#!\\/usr\\/bin\\/env runhaskell",end:"$"},i,a,e.QUOTE_STRING_MODE,e.C_NUMBER_MODE,s,e.inherit(e.TITLE_MODE,{begin:"^[_a-z][\\w']*"}),n,{begin:"->|<-"}]}}}());
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 hljs.registerLanguage("nim",function(){"use strict";return function(e){return{name:"Nim",aliases:["nim"],keywords:{keyword:"addr and as asm bind block break case cast const continue converter discard distinct div do elif else end enum except export finally for from func generic if import in include interface is isnot iterator let macro method mixin mod nil not notin object of or out proc ptr raise ref return shl shr static template try tuple type using var when while with without xor yield",literal:"shared guarded stdin stdout stderr result true false",built_in:"int int8 int16 int32 int64 uint uint8 uint16 uint32 uint64 float float32 float64 bool char string cstring pointer expr stmt void auto any range array openarray varargs seq set clong culong cchar cschar cshort cint csize clonglong cfloat cdouble clongdouble cuchar cushort cuint culonglong cstringarray semistatic"},contains:[{className:"meta",begin:/{\./,end:/\.}/,relevance:10},{className:"string",begin:/[a-zA-Z]\w*"/,end:/"/,contains:[{begin:/""/}]},{className:"string",begin:/([a-zA-Z]\w*)?"""/,end:/"""/},e.QUOTE_STRING_MODE,{className:"type",begin:/\b[A-Z]\w+\b/,relevance:0},{className:"number",relevance:0,variants:[{begin:/\b(0[xX][0-9a-fA-F][_0-9a-fA-F]*)('?[iIuU](8|16|32|64))?/},{begin:/\b(0o[0-7][_0-7]*)('?[iIuUfF](8|16|32|64))?/},{begin:/\b(0(b|B)[01][_01]*)('?[iIuUfF](8|16|32|64))?/},{begin:/\b(\d[_\d]*)('?[iIuUfF](8|16|32|64))?/}]},e.HASH_COMMENT_MODE]}}}());
+hljs.registerLanguage("nix",function(){"use strict";return function(e){var n={keyword:"rec with let in inherit assert if else then",literal:"true false or and null",built_in:"import abort baseNameOf dirOf isNull builtins map removeAttrs throw toString derivation"},i={className:"subst",begin:/\$\{/,end:/}/,keywords:n},t={className:"string",contains:[i],variants:[{begin:"''",end:"''"},{begin:'"',end:'"'}]},s=[e.NUMBER_MODE,e.HASH_COMMENT_MODE,e.C_BLOCK_COMMENT_MODE,t,{begin:/[a-zA-Z0-9-_]+(\s*=)/,returnBegin:!0,relevance:0,contains:[{className:"attr",begin:/\S+/}]}];return i.contains=s,{name:"Nix",aliases:["nixos"],keywords:n,contains:s}}}());
 hljs.registerLanguage("r",function(){"use strict";return function(e){var n="([a-zA-Z]|\\.[a-zA-Z.])[a-zA-Z0-9._]*";return{name:"R",contains:[e.HASH_COMMENT_MODE,{begin:n,keywords:{$pattern:n,keyword:"function if in break next repeat else for return switch while try tryCatch stop warning require library attach detach source setMethod setGeneric setGroupGeneric setClass ...",literal:"NULL NA TRUE FALSE T F Inf NaN NA_integer_|10 NA_real_|10 NA_character_|10 NA_complex_|10"},relevance:0},{className:"number",begin:"0[xX][0-9a-fA-F]+[Li]?\\b",relevance:0},{className:"number",begin:"\\d+(?:[eE][+\\-]?\\d*)?L\\b",relevance:0},{className:"number",begin:"\\d+\\.(?!\\d)(?:i\\b)?",relevance:0},{className:"number",begin:"\\d+(?:\\.\\d*)?(?:[eE][+\\-]?\\d*)?i?\\b",relevance:0},{className:"number",begin:"\\.\\d+(?:[eE][+\\-]?\\d*)?i?\\b",relevance:0},{begin:"`",end:"`",relevance:0},{className:"string",contains:[e.BACKSLASH_ESCAPE],variants:[{begin:'"',end:'"'},{begin:"'",end:"'"}]}]}}}());
 hljs.registerLanguage("scala",function(){"use strict";return function(e){var n={className:"subst",variants:[{begin:"\\$[A-Za-z0-9_]+"},{begin:"\\${",end:"}"}]},a={className:"string",variants:[{begin:'"',end:'"',illegal:"\\n",contains:[e.BACKSLASH_ESCAPE]},{begin:'"""',end:'"""',relevance:10},{begin:'[a-z]+"',end:'"',illegal:"\\n",contains:[e.BACKSLASH_ESCAPE,n]},{className:"string",begin:'[a-z]+"""',end:'"""',contains:[n],relevance:10}]},s={className:"type",begin:"\\b[A-Z][A-Za-z0-9_]*",relevance:0},t={className:"title",begin:/[^0-9\n\t "'(),.`{}\[\]:;][^\n\t "'(),.`{}\[\]:;]+|[^0-9\n\t "'(),.`{}\[\]:;=]/,relevance:0},i={className:"class",beginKeywords:"class object trait type",end:/[:={\[\n;]/,excludeEnd:!0,contains:[{beginKeywords:"extends with",relevance:10},{begin:/\[/,end:/\]/,excludeBegin:!0,excludeEnd:!0,relevance:0,contains:[s]},{className:"params",begin:/\(/,end:/\)/,excludeBegin:!0,excludeEnd:!0,relevance:0,contains:[s]},t]},l={className:"function",beginKeywords:"def",end:/[:={\[(\n;]/,excludeEnd:!0,contains:[t]};return{name:"Scala",keywords:{literal:"true false null",keyword:"type yield lazy override def with val var sealed abstract private trait object if forSome for while throw finally protected extends import final return else break new catch super class case package default try this match continue throws implicit"},contains:[e.C_LINE_COMMENT_MODE,e.C_BLOCK_COMMENT_MODE,a,{className:"symbol",begin:"'\\w[\\w\\d_]*(?!')"},s,l,i,e.C_NUMBER_MODE,{className:"meta",begin:"@[A-Za-z]+"}]}}}());
 hljs.registerLanguage("x86asm",function(){"use strict";return function(s){return{name:"Intel x86 Assembly",case_insensitive:!0,keywords:{$pattern:"[.%]?"+s.IDENT_RE,keyword:"lock rep repe repz repne repnz xaquire xrelease bnd nobnd aaa aad aam aas adc add and arpl bb0_reset bb1_reset bound bsf bsr bswap bt btc btr bts call cbw cdq cdqe clc cld cli clts cmc cmp cmpsb cmpsd cmpsq cmpsw cmpxchg cmpxchg486 cmpxchg8b cmpxchg16b cpuid cpu_read cpu_write cqo cwd cwde daa das dec div dmint emms enter equ f2xm1 fabs fadd faddp fbld fbstp fchs fclex fcmovb fcmovbe fcmove fcmovnb fcmovnbe fcmovne fcmovnu fcmovu fcom fcomi fcomip fcomp fcompp fcos fdecstp fdisi fdiv fdivp fdivr fdivrp femms feni ffree ffreep fiadd ficom ficomp fidiv fidivr fild fimul fincstp finit fist fistp fisttp fisub fisubr fld fld1 fldcw fldenv fldl2e fldl2t fldlg2 fldln2 fldpi fldz fmul fmulp fnclex fndisi fneni fninit fnop fnsave fnstcw fnstenv fnstsw fpatan fprem fprem1 fptan frndint frstor fsave fscale fsetpm fsin 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vcvttsd2si vcvttss2si vdivpd vdivps vdivsd vdivss vdppd vdpps vextractf128 vextractps vhaddpd vhaddps vhsubpd vhsubps vinsertf128 vinsertps vlddqu vldqqu vldmxcsr vmaskmovdqu vmaskmovps vmaskmovpd vmaxpd vmaxps vmaxsd vmaxss vminpd vminps vminsd vminss vmovapd vmovaps vmovd vmovq vmovddup vmovdqa vmovqqa vmovdqu vmovqqu vmovhlps vmovhpd vmovhps vmovlhps vmovlpd vmovlps vmovmskpd vmovmskps vmovntdq vmovntqq vmovntdqa vmovntpd vmovntps vmovsd vmovshdup vmovsldup vmovss vmovupd vmovups vmpsadbw vmulpd vmulps vmulsd vmulss vorpd vorps vpabsb vpabsw vpabsd vpacksswb vpackssdw vpackuswb vpackusdw vpaddb vpaddw vpaddd vpaddq vpaddsb vpaddsw vpaddusb vpaddusw vpalignr vpand vpandn vpavgb vpavgw vpblendvb vpblendw vpcmpestri vpcmpestrm vpcmpistri vpcmpistrm vpcmpeqb vpcmpeqw vpcmpeqd vpcmpeqq vpcmpgtb vpcmpgtw vpcmpgtd vpcmpgtq vpermilpd vpermilps vperm2f128 vpextrb vpextrw vpextrd vpextrq vphaddw vphaddd vphaddsw vphminposuw vphsubw vphsubd vphsubsw vpinsrb vpinsrw vpinsrd vpinsrq vpmaddwd 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vfmadd132ps vfmadd132pd vfmadd312ps vfmadd312pd vfmadd213ps vfmadd213pd vfmadd123ps vfmadd123pd vfmadd231ps vfmadd231pd vfmadd321ps vfmadd321pd vfmaddsub132ps vfmaddsub132pd vfmaddsub312ps vfmaddsub312pd vfmaddsub213ps vfmaddsub213pd vfmaddsub123ps vfmaddsub123pd vfmaddsub231ps vfmaddsub231pd vfmaddsub321ps vfmaddsub321pd vfmsub132ps vfmsub132pd vfmsub312ps vfmsub312pd vfmsub213ps vfmsub213pd vfmsub123ps vfmsub123pd vfmsub231ps vfmsub231pd vfmsub321ps vfmsub321pd vfmsubadd132ps vfmsubadd132pd vfmsubadd312ps vfmsubadd312pd vfmsubadd213ps vfmsubadd213pd vfmsubadd123ps vfmsubadd123pd vfmsubadd231ps vfmsubadd231pd vfmsubadd321ps vfmsubadd321pd vfnmadd132ps vfnmadd132pd vfnmadd312ps vfnmadd312pd vfnmadd213ps vfnmadd213pd vfnmadd123ps vfnmadd123pd vfnmadd231ps vfnmadd231pd vfnmadd321ps vfnmadd321pd vfnmsub132ps vfnmsub132pd vfnmsub312ps vfnmsub312pd vfnmsub213ps vfnmsub213pd vfnmsub123ps vfnmsub123pd vfnmsub231ps vfnmsub231pd vfnmsub321ps vfnmsub321pd vfmadd132ss vfmadd132sd vfmadd312ss vfmadd312sd vfmadd213ss vfmadd213sd vfmadd123ss vfmadd123sd vfmadd231ss vfmadd231sd vfmadd321ss vfmadd321sd vfmsub132ss vfmsub132sd vfmsub312ss vfmsub312sd vfmsub213ss vfmsub213sd vfmsub123ss vfmsub123sd vfmsub231ss vfmsub231sd vfmsub321ss vfmsub321sd vfnmadd132ss vfnmadd132sd vfnmadd312ss vfnmadd312sd vfnmadd213ss vfnmadd213sd vfnmadd123ss vfnmadd123sd vfnmadd231ss vfnmadd231sd vfnmadd321ss vfnmadd321sd vfnmsub132ss vfnmsub132sd vfnmsub312ss vfnmsub312sd vfnmsub213ss vfnmsub213sd vfnmsub123ss vfnmsub123sd vfnmsub231ss vfnmsub231sd vfnmsub321ss vfnmsub321sd rdfsbase rdgsbase rdrand wrfsbase wrgsbase vcvtph2ps vcvtps2ph adcx adox rdseed clac stac xstore xcryptecb xcryptcbc xcryptctr xcryptcfb xcryptofb montmul xsha1 xsha256 llwpcb slwpcb lwpval lwpins vfmaddpd vfmaddps vfmaddsd vfmaddss vfmaddsubpd vfmaddsubps vfmsubaddpd vfmsubaddps vfmsubpd vfmsubps vfmsubsd vfmsubss vfnmaddpd vfnmaddps vfnmaddsd vfnmaddss vfnmsubpd vfnmsubps vfnmsubsd vfnmsubss vfrczpd vfrczps vfrczsd vfrczss vpcmov vpcomb vpcomd vpcomq vpcomub vpcomud vpcomuq vpcomuw vpcomw vphaddbd vphaddbq vphaddbw vphadddq vphaddubd vphaddubq vphaddubw vphaddudq vphadduwd vphadduwq vphaddwd vphaddwq vphsubbw vphsubdq vphsubwd vpmacsdd vpmacsdqh vpmacsdql vpmacssdd vpmacssdqh vpmacssdql vpmacsswd vpmacssww vpmacswd vpmacsww vpmadcsswd vpmadcswd vpperm vprotb vprotd vprotq vprotw vpshab vpshad vpshaq vpshaw vpshlb vpshld vpshlq vpshlw vbroadcasti128 vpblendd vpbroadcastb vpbroadcastw vpbroadcastd vpbroadcastq vpermd vpermpd vpermps vpermq vperm2i128 vextracti128 vinserti128 vpmaskmovd vpmaskmovq vpsllvd vpsllvq vpsravd vpsrlvd vpsrlvq vgatherdpd vgatherqpd vgatherdps vgatherqps vpgatherdd vpgatherqd vpgatherdq vpgatherqq xabort xbegin xend xtest andn bextr blci blcic blsi blsic blcfill blsfill blcmsk blsmsk blsr blcs bzhi mulx pdep pext rorx sarx shlx shrx tzcnt tzmsk t1mskc valignd valignq vblendmpd vblendmps vbroadcastf32x4 vbroadcastf64x4 vbroadcasti32x4 vbroadcasti64x4 vcompresspd vcompressps vcvtpd2udq vcvtps2udq vcvtsd2usi vcvtss2usi vcvttpd2udq vcvttps2udq vcvttsd2usi vcvttss2usi vcvtudq2pd vcvtudq2ps vcvtusi2sd vcvtusi2ss vexpandpd vexpandps vextractf32x4 vextractf64x4 vextracti32x4 vextracti64x4 vfixupimmpd vfixupimmps vfixupimmsd vfixupimmss vgetexppd vgetexpps vgetexpsd vgetexpss vgetmantpd vgetmantps vgetmantsd vgetmantss vinsertf32x4 vinsertf64x4 vinserti32x4 vinserti64x4 vmovdqa32 vmovdqa64 vmovdqu32 vmovdqu64 vpabsq vpandd vpandnd vpandnq vpandq vpblendmd vpblendmq vpcmpltd vpcmpled vpcmpneqd vpcmpnltd vpcmpnled vpcmpd vpcmpltq vpcmpleq vpcmpneqq vpcmpnltq vpcmpnleq vpcmpq vpcmpequd vpcmpltud vpcmpleud vpcmpnequd vpcmpnltud vpcmpnleud vpcmpud vpcmpequq vpcmpltuq vpcmpleuq vpcmpnequq vpcmpnltuq vpcmpnleuq vpcmpuq vpcompressd vpcompressq vpermi2d vpermi2pd vpermi2ps vpermi2q vpermt2d vpermt2pd vpermt2ps vpermt2q vpexpandd vpexpandq vpmaxsq vpmaxuq vpminsq vpminuq vpmovdb vpmovdw vpmovqb vpmovqd vpmovqw vpmovsdb vpmovsdw vpmovsqb vpmovsqd vpmovsqw vpmovusdb vpmovusdw vpmovusqb vpmovusqd vpmovusqw vpord vporq vprold vprolq vprolvd vprolvq vprord vprorq vprorvd vprorvq vpscatterdd vpscatterdq vpscatterqd vpscatterqq vpsraq vpsravq vpternlogd vpternlogq vptestmd vptestmq vptestnmd vptestnmq vpxord vpxorq vrcp14pd vrcp14ps vrcp14sd vrcp14ss vrndscalepd vrndscaleps vrndscalesd vrndscaless vrsqrt14pd vrsqrt14ps vrsqrt14sd vrsqrt14ss vscalefpd vscalefps vscalefsd vscalefss vscatterdpd vscatterdps vscatterqpd vscatterqps vshuff32x4 vshuff64x2 vshufi32x4 vshufi64x2 kandnw kandw kmovw knotw kortestw korw kshiftlw kshiftrw kunpckbw kxnorw kxorw vpbroadcastmb2q vpbroadcastmw2d vpconflictd vpconflictq vplzcntd vplzcntq vexp2pd vexp2ps vrcp28pd vrcp28ps vrcp28sd vrcp28ss vrsqrt28pd vrsqrt28ps vrsqrt28sd vrsqrt28ss vgatherpf0dpd vgatherpf0dps vgatherpf0qpd vgatherpf0qps vgatherpf1dpd vgatherpf1dps vgatherpf1qpd vgatherpf1qps vscatterpf0dpd vscatterpf0dps vscatterpf0qpd vscatterpf0qps vscatterpf1dpd vscatterpf1dps vscatterpf1qpd vscatterpf1qps prefetchwt1 bndmk bndcl bndcu bndcn bndmov bndldx bndstx sha1rnds4 sha1nexte sha1msg1 sha1msg2 sha256rnds2 sha256msg1 sha256msg2 hint_nop0 hint_nop1 hint_nop2 hint_nop3 hint_nop4 hint_nop5 hint_nop6 hint_nop7 hint_nop8 hint_nop9 hint_nop10 hint_nop11 hint_nop12 hint_nop13 hint_nop14 hint_nop15 hint_nop16 hint_nop17 hint_nop18 hint_nop19 hint_nop20 hint_nop21 hint_nop22 hint_nop23 hint_nop24 hint_nop25 hint_nop26 hint_nop27 hint_nop28 hint_nop29 hint_nop30 hint_nop31 hint_nop32 hint_nop33 hint_nop34 hint_nop35 hint_nop36 hint_nop37 hint_nop38 hint_nop39 hint_nop40 hint_nop41 hint_nop42 hint_nop43 hint_nop44 hint_nop45 hint_nop46 hint_nop47 hint_nop48 hint_nop49 hint_nop50 hint_nop51 hint_nop52 hint_nop53 hint_nop54 hint_nop55 hint_nop56 hint_nop57 hint_nop58 hint_nop59 hint_nop60 hint_nop61 hint_nop62 hint_nop63",built_in:"ip eip rip al ah bl bh cl ch dl dh sil dil bpl spl r8b r9b r10b r11b r12b r13b r14b r15b ax bx cx dx si di bp sp r8w r9w r10w r11w r12w r13w r14w r15w eax ebx ecx edx esi edi ebp esp eip r8d r9d r10d r11d r12d r13d r14d r15d rax rbx rcx rdx rsi rdi rbp rsp r8 r9 r10 r11 r12 r13 r14 r15 cs ds es fs gs ss st st0 st1 st2 st3 st4 st5 st6 st7 mm0 mm1 mm2 mm3 mm4 mm5 mm6 mm7 xmm0  xmm1  xmm2  xmm3  xmm4  xmm5  xmm6  xmm7  xmm8  xmm9 xmm10  xmm11 xmm12 xmm13 xmm14 xmm15 xmm16 xmm17 xmm18 xmm19 xmm20 xmm21 xmm22 xmm23 xmm24 xmm25 xmm26 xmm27 xmm28 xmm29 xmm30 xmm31 ymm0  ymm1  ymm2  ymm3  ymm4  ymm5  ymm6  ymm7  ymm8  ymm9 ymm10  ymm11 ymm12 ymm13 ymm14 ymm15 ymm16 ymm17 ymm18 ymm19 ymm20 ymm21 ymm22 ymm23 ymm24 ymm25 ymm26 ymm27 ymm28 ymm29 ymm30 ymm31 zmm0  zmm1  zmm2  zmm3  zmm4  zmm5  zmm6  zmm7  zmm8  zmm9 zmm10  zmm11 zmm12 zmm13 zmm14 zmm15 zmm16 zmm17 zmm18 zmm19 zmm20 zmm21 zmm22 zmm23 zmm24 zmm25 zmm26 zmm27 zmm28 zmm29 zmm30 zmm31 k0 k1 k2 k3 k4 k5 k6 k7 bnd0 bnd1 bnd2 bnd3 cr0 cr1 cr2 cr3 cr4 cr8 dr0 dr1 dr2 dr3 dr8 tr3 tr4 tr5 tr6 tr7 r0 r1 r2 r3 r4 r5 r6 r7 r0b r1b r2b r3b r4b r5b r6b r7b r0w r1w r2w r3w r4w r5w r6w r7w r0d r1d r2d r3d r4d r5d r6d r7d r0h r1h r2h r3h r0l r1l r2l r3l r4l r5l r6l r7l r8l r9l r10l r11l r12l r13l r14l r15l db dw dd dq dt ddq do dy dz resb resw resd resq rest resdq reso resy resz incbin equ times byte word dword qword nosplit rel abs seg wrt strict near far a32 ptr",meta:"%define %xdefine %+ %undef %defstr %deftok %assign %strcat %strlen %substr %rotate %elif %else %endif %if %ifmacro %ifctx %ifidn %ifidni %ifid %ifnum %ifstr %iftoken %ifempty %ifenv %error %warning %fatal %rep %endrep %include %push %pop %repl %pathsearch %depend %use %arg %stacksize %local %line %comment %endcomment .nolist __FILE__ __LINE__ __SECT__  __BITS__ __OUTPUT_FORMAT__ __DATE__ __TIME__ __DATE_NUM__ __TIME_NUM__ __UTC_DATE__ __UTC_TIME__ __UTC_DATE_NUM__ __UTC_TIME_NUM__  __PASS__ struc endstruc istruc at iend align alignb sectalign daz nodaz up down zero default option assume public bits use16 use32 use64 default section segment absolute extern global common cpu float __utf16__ __utf16le__ __utf16be__ __utf32__ __utf32le__ __utf32be__ __float8__ __float16__ __float32__ __float64__ __float80m__ __float80e__ __float128l__ __float128h__ __Infinity__ __QNaN__ __SNaN__ Inf NaN QNaN SNaN float8 float16 float32 float64 float80m float80e float128l float128h __FLOAT_DAZ__ __FLOAT_ROUND__ __FLOAT__"},contains:[s.COMMENT(";","$",{relevance:0}),{className:"number",variants:[{begin:"\\b(?:([0-9][0-9_]*)?\\.[0-9_]*(?:[eE][+-]?[0-9_]+)?|(0[Xx])?[0-9][0-9_]*\\.?[0-9_]*(?:[pP](?:[+-]?[0-9_]+)?)?)\\b",relevance:0},{begin:"\\$[0-9][0-9A-Fa-f]*",relevance:0},{begin:"\\b(?:[0-9A-Fa-f][0-9A-Fa-f_]*[Hh]|[0-9][0-9_]*[DdTt]?|[0-7][0-7_]*[QqOo]|[0-1][0-1_]*[BbYy])\\b"},{begin:"\\b(?:0[Xx][0-9A-Fa-f_]+|0[DdTt][0-9_]+|0[QqOo][0-7_]+|0[BbYy][0-1_]+)\\b"}]},s.QUOTE_STRING_MODE,{className:"string",variants:[{begin:"'",end:"[^\\\\]'"},{begin:"`",end:"[^\\\\]`"}],relevance:0},{className:"symbol",variants:[{begin:"^\\s*[A-Za-z._?][A-Za-z0-9_$#@~.?]*(:|\\s+label)"},{begin:"^\\s*%%[A-Za-z0-9_$#@~.?]*:"}],relevance:0},{className:"subst",begin:"%[0-9]+",relevance:0},{className:"subst",begin:"%!S+",relevance:0},{className:"meta",begin:/^\s*\.[\w_-]+/}]}}}());
\ No newline at end of file


Test patch:
diff --git a/test_book/src/languages/README.md b/test_book/src/languages/README.md
index 4f70dd1af3..32c293f538 100644
--- a/test_book/src/languages/README.md
+++ b/test_book/src/languages/README.md
@@ -28,6 +28,7 @@ This Currently contains following languages
 - markdown
 - nginx
 - nim
+- nix
 - objectivec
 - perl
 - php
diff --git a/test_book/src/languages/highlight.md b/test_book/src/languages/highlight.md
index 371e315a9c..6f3d19ca91 100644
--- a/test_book/src/languages/highlight.md
+++ b/test_book/src/languages/highlight.md
@@ -563,6 +563,15 @@ int main(int argc, const char * argv[]) {
 
 ```
 
+## nix
+
+```nix
+let
+  world = "World!";
+in
+"Hello " + world
+```
+
 ## perl
 
 ```perl