Merge pull request #32 from Freed-Wu/keyword

Update syntax

syntax/requirements.vim

@@ -30,6 +30,12 @@ endif
 
 syn case match
 
+" https://pip.pypa.io/en/stable/reference/requirements-file-format/
+" https://pip.pypa.io/en/stable/reference/inspect-report/#example
+syn keyword requirementsKeyword implementation_name implementation_version os_name platform_machine platform_release platform_system platform_version python_full_version platform_python_implementation python_version sys_platform contained
+syn region requirementsSubst matchgroup=requirementsSubstDelim start="\V${" end="\V}"
+syn region requirementsString matchgroup=requirementsStringDelim start=`'` skip=`\\'` end=`'`
+syn region requirementsString matchgroup=requirementsStringDelim start=`"` skip=`\\"` end=`"`
 syn match requirementsVersion "\v\d+[a-zA-Z0-9\.\-\*]*"
 syn region requirementsComment start="[ \t]*#" end="$"
 syn match requirementsCommandOption "\v^\[?--?[a-zA-Z\-]*\]?"
@@ -38,8 +44,13 @@ syn match requirementsPackageName "\v^([a-zA-Z0-9][a-zA-Z0-9\-_\.]*[a-zA-Z0-9])"
 syn match requirementsExtras "\v\[\S+\]"
 syn match requirementsVersionControls "\v(git\+?|hg\+|svn\+|bzr\+).*://.\S+"
 syn match requirementsURLs "\v(\@\s)?(https?|ftp|gopher)://?[^\s/$.?#].\S*"
-syn match requirementsEnvironmentMarkers "\v;\s[^#]+"
+syn match requirementsEnvironmentMarkers "\v;\s[^#]+" contains=requirementsKeyword,requirementsVersionSpecifiers,requirementsString
 
+hi def link requirementsKeyword Keyword
+hi def link requirementsSubstDelim Delimiter
+hi def link requirementsSubst PreProc
+hi def link requirementsStringDelim Delimiter
+hi def link requirementsString String
 hi def link requirementsVersion Number
 hi def link requirementsComment Comment
 hi def link requirementsCommandOption Special