" Vim syntax file
" Language:	Motorola S-Record
" Maintainer:	Markus Heidelberg <markus.heidelberg@web.de>
" Last Change:	2015 Feb 24

" Each record (line) is built as follows:
"
"    field       digits          states
"
"  +----------+
"  | start    |  1 ('S')         srecRecStart
"  +----------+
"  | type     |  1               srecRecType, (srecRecTypeUnknown)
"  +----------+
"  | count    |  2               srecByteCount
"  +----------+
"  | address  |  4/6/8           srecNoAddress, srecDataAddress, srecRecCount, srecStartAddress, (srecAddressFieldUnknown)
"  +----------+
"  | data     |  0..504/502/500  srecDataOdd, srecDataEven, (srecDataUnexpected)
"  +----------+
"  | checksum |  2               srecChecksum
"  +----------+
"
" States in parentheses in the upper format description indicate that they
" should not appear in a valid file.

" quit when a syntax file was already loaded
if exists("b:current_syntax")
  finish
endif

syn match srecRecStart "^S"

syn match srecRecTypeUnknown "^S."        contains=srecRecStart
syn match srecRecType        "^S[0-35-9]" contains=srecRecStart

syn match srecByteCount "^S.[0-9a-fA-F]\{2}"        contains=srecRecTypeUnknown nextgroup=srecAddressFieldUnknown,srecChecksum
syn match srecByteCount "^S[0-35-9][0-9a-fA-F]\{2}" contains=srecRecType

syn match srecAddressFieldUnknown "[0-9a-fA-F]\{2}" contained nextgroup=srecAddressFieldUnknown,srecChecksum

syn match srecNoAddress    "^S0[0-9a-fA-F]\{6}"  contains=srecByteCount nextgroup=srecDataOdd,srecChecksum
syn match srecDataAddress  "^S1[0-9a-fA-F]\{6}"  contains=srecByteCount nextgroup=srecDataOdd,srecChecksum
syn match srecDataAddress  "^S2[0-9a-fA-F]\{8}"  contains=srecByteCount nextgroup=srecDataOdd,srecChecksum
syn match srecDataAddress  "^S3[0-9a-fA-F]\{10}" contains=srecByteCount nextgroup=srecDataOdd,srecChecksum
syn match srecRecCount     "^S5[0-9a-fA-F]\{6}"  contains=srecByteCount nextgroup=srecDataUnexpected,srecChecksum
syn match srecRecCount     "^S6[0-9a-fA-F]\{8}"  contains=srecByteCount nextgroup=srecDataUnexpected,srecChecksum
syn match srecStartAddress "^S7[0-9a-fA-F]\{10}" contains=srecByteCount nextgroup=srecDataUnexpected,srecChecksum
syn match srecStartAddress "^S8[0-9a-fA-F]\{8}"  contains=srecByteCount nextgroup=srecDataUnexpected,srecChecksum
syn match srecStartAddress "^S9[0-9a-fA-F]\{6}"  contains=srecByteCount nextgroup=srecDataUnexpected,srecChecksum

" alternating highlight per byte for easier reading
syn match srecDataOdd        "[0-9a-fA-F]\{2}" contained nextgroup=srecDataEven,srecChecksum
syn match srecDataEven       "[0-9a-fA-F]\{2}" contained nextgroup=srecDataOdd,srecChecksum
" data bytes which should not exist
syn match srecDataUnexpected "[0-9a-fA-F]\{2}" contained nextgroup=srecDataUnexpected,srecChecksum
" Data digit pair regex usage also results in only highlighting the checksum
" if the number of data characters is even.

syn match srecChecksum "[0-9a-fA-F]\{2}$" contained

" Define the default highlighting.
" Only when an item doesn't have highlighting yet

" The default methods for highlighting. Can be overridden later
hi def link srecRecStart            srecRecType
hi def link srecRecTypeUnknown      srecRecType
hi def link srecRecType             WarningMsg
hi def link srecByteCount           Constant
hi def srecAddressFieldUnknown term=italic cterm=italic gui=italic
hi def link srecNoAddress           DiffAdd
hi def link srecDataAddress         Comment
hi def link srecRecCount            srecNoAddress
hi def link srecStartAddress        srecDataAddress
hi def srecDataOdd             term=bold cterm=bold gui=bold
hi def srecDataEven            term=NONE cterm=NONE gui=NONE
hi def link srecDataUnexpected      Error
hi def link srecChecksum            DiffChange


let b:current_syntax = "srec"

" vim: ts=8
