Added USD as a language + some queries

Added USD highlight unittests

Added USD indentation

Added USD indents.scm file

Added USD indent rules

Simplified USD highlight groups

Added explicit highlight groups

Added newline

Removed after/ftdetect/usda.lua

usd/indents.scm - Added inline comments explaining the nodes

Fixed USD highlight group unittests

Added indentation unittests

Simplified USD `@identifier` highlighting

Added USD documentation highlight group tests

Simplified USD highlight groups

Moved USD `@identifier` and `@namespace` highlights into one place

Removed and simplified tests/query/highlights/usd

Simplified tests/query/highlights/usd more

Removed trailing newline

Combined USD test files

Added `set filetype=usd` to minimal_init.lua

4 files changed, 214 insertions, 0 deletions

diff --git a/queries/usd/folds.scm b/queries/usd/folds.scm
new file mode 100644
index 000000000..c4815bd07
--- /dev/null
+++ b/queries/usd/folds.scm
@@ -0,0 +1,3 @@
+[
+  (block)
+] @fold
diff --git a/queries/usd/highlights.scm b/queries/usd/highlights.scm
new file mode 100644
index 000000000..73968a647
--- /dev/null
+++ b/queries/usd/highlights.scm
@@ -0,0 +1,181 @@
+(None) @constant.builtin
+(asset_path) @text.uri
+(attribute_property) @property
+(bool) @boolean
+(comment) @comment @spell
+(custom) @function.builtin
+(float) @float
+(integer) @number
+(orderer) @function.call
+(prim_path) @string.special
+(relationship_type) @type
+(string) @string
+(uniform) @function.builtin
+(variant_set_definition) @keyword
+
+;; Prefer namespace highlighting, if any.
+;;
+;; e.g. `rel fizz` - `fizz` uses `@identifier`
+;; e.g. `rel foo:bar:fizz` - `foo` and `bar` use `@namespace` and `fizz` uses `@identifier`
+;;
+(identifier) @variable
+(namespace_identifier) @namespace
+(namespace_identifier
+  (identifier) @namespace
+)
+
+[
+  "class"
+  "def"
+  "over"
+] @keyword.function
+
+["(" ")" "[" "]" "{" "}"] @punctuation.bracket
+[":" ";" "."] @punctuation.delimiter
+
+[
+  "="
+] @operator
+
+(attribute_type) @type
+(
+ ;; Reference: https://openusd.org/release/api/sdf_page_front.html
+ (attribute_type) @type.builtin
+ (#any-of? @type.builtin
+  ;; Scalar types
+  "asset" "asset[]"
+  "bool" "bool[]"
+  "double" "double[]"
+  "float" "float[]"
+  "half" "half[]"
+  "int" "int[]"
+  "int64" "int64[]"
+  "string" "string[]"
+  "timecode" "timecode[]"
+  "token" "token[]"
+  "uchar" "uchar[]"
+  "uint" "uint[]"
+  "uint64" "uint64[]"
+
+  ;; Dimensioned Types
+  "double2" "double2[]"
+  "double3" "double3[]"
+  "double4" "double4[]"
+  "float2" "float2[]"
+  "float3" "float3[]"
+  "float4" "float4[]"
+  "half2" "half2[]"
+  "half3" "half3[]"
+  "half4" "half4[]"
+  "int2" "int2[]"
+  "int3" "int3[]"
+  "int4" "int4[]"
+  "matrix2d" "matrix2d[]"
+  "matrix3d" "matrix3d[]"
+  "matrix4d" "matrix4d[]"
+  "quatd" "quatd[]"
+  "quatf" "quatf[]"
+  "quath" "quath[]"
+
+  ;; Extra Types
+  "color3f" "color3f[]"
+  "normal3f" "normal3f[]"
+  "point3f" "point3f[]"
+  "texCoord2f" "texCoord2f[]"
+  "vector3d" "vector3d[]"
+  "vector3f" "vector3f[]"
+  "vector3h" "vector3h[]"
+
+  "dictionary"
+
+  ;; Deprecated Types
+  "EdgeIndex" "EdgeIndex[]"
+  "FaceIndex" "FaceIndex[]"
+  "Matrix4d" "Matrix4d[]"
+  "PointIndex" "PointIndex[]"
+  "PointFloat" "PointFloat[]"
+  "Transform" "Transform[]"
+  "Vec3f" "Vec3f[]"
+ )
+)
+
+(
+ (identifier) @keyword
+ (#any-of? @keyword
+
+  ;; Reference: https://openusd.org/release/api/sdf_page_front.html
+  ;; LIVRPS names
+  "inherits"
+  "payload"
+  "references"
+  "specializes"
+  "variantSets"
+  "variants"
+
+  ; assetInfo names
+  "assetInfo"
+  "identifier"
+  "name"
+  "payloadAssetDependencies"
+  "version"
+
+  ;; clips names
+  "clips"
+
+  "active"
+  "assetPaths"
+  "manifestAssetPath"
+  "primPath"
+  "templateAssetPath"
+  "templateEndTime"
+  "templateStartTime"
+  "templateStride"
+  "times"
+
+  ;; customData names
+  "customData"
+
+  "apiSchemaAutoApplyTo"
+  "apiSchemaOverridePropertyNames"
+  "className"
+  "extraPlugInfo"
+  "isUsdShadeContainer"
+  "libraryName"
+  "providesUsdShadeConnectableAPIBehavior"
+  "requiresUsdShadeEncapsulation"
+  "skipCodeGeneration"
+
+  ;; Layer metadata names
+  "colorConfiguration"
+  "colorManagementSystem"
+  "customLayerData"
+  "defaultPrim"
+  "doc"
+  "endTimeCode"
+  "framesPerSecond"
+  "owner"
+  "startTimeCode"
+  "subLayers"
+
+  ;; Prim metadata
+  "instanceable"
+ )
+)
+
+;; Common attribute metadata
+(
+ (layer_offset
+  (identifier) @keyword
+  (#any-of? @keyword
+
+   "offset"
+   "scale"
+  )
+ )
+)
+
+;; Docstrings in USD
+(metadata
+ (comment)*
+ (string) @comment.documentation
+)
diff --git a/queries/usd/indents.scm b/queries/usd/indents.scm
new file mode 100644
index 000000000..4af153034
--- /dev/null
+++ b/queries/usd/indents.scm
@@ -0,0 +1,26 @@
+[
+  (block)  ; The {}s in `def "foo" { ... Attributes / Prims here ... }`
+  (dictionary)  ; The {}s in `dictionary foo = { string "foo" = "bar" }`
+  (list)
+  (list_proxy)  ; [@foo.usda@, @bar.usda@]
+  (metadata)  ; ( anything = "goes-here" )
+  (prim_paths)  ; [</foo>, <../bar>]
+  (timeSamples)  ; The {}s in `int value.timeSamples = { 0: 1, -10: 10, ... }`
+  (tuple)
+  (variant_set_definition)  ; The {}s in `variantSet "foo" = { "vr1" { ... } "vr2" { ... } }`
+] @indent.begin
+
+(block "}" @indent.end)
+(dictionary "}" @indent.end)
+(list "]" @indent.end)
+(list_proxy "]" @indent.end)
+(metadata ")" @indent.end)
+(timeSamples "}" @indent.end)
+(tuple ")" @indent.end)
+(variant_set_definition "}" @indent.end)
+
+[
+  ")"
+  "]"
+  "}"
+] @indent.branch
diff --git a/queries/usd/locals.scm b/queries/usd/locals.scm
new file mode 100644
index 000000000..4e7e97b5f
--- /dev/null
+++ b/queries/usd/locals.scm
@@ -0,0 +1,4 @@
+[
+  (block)
+  (metadata)
+] @scope