" Vim syntax file
" Language: J
" Maintainer: David Bürgin <[email protected]>
" Last Change: 2013-09-21

if exists("b:current_syntax")
finish
endif

syntax case match
syntax sync minlines=50

syn match jControl /\<\%(assert\|break\|case\|catch[dt]\=\|continue\|do\|else\%(if\)\=\|end\|fcase\|for\|if\|return\|select\|throw\|try\|whil\%(e\|st\)\)\./
syn match jControl /\<\%(for\|goto\|label\)_\a\k*\./

syn region jString oneline start=/'/ skip=/''/ end=/'/

" Patterns for numbers in general, rational numbers, numbers with explicit
" base, infinities, and numbers with extended precision.
"
" Matching J numbers is difficult. The regular expression used for the general
" case roughly embodies this grammar sketch:
"
" EXP := /_?\d+(\.\d*)?([eE]_?\d+)?/
" COMP := EXP | EXP (j|a[dr]) EXP
" PIEU := COMP | COMP [px] COMP
"
" For the rest, a compromise between correctness and practicality was made.
" See http://www.jsoftware.com/help/dictionary/dcons.htm for reference.
syn match jNumber /\<_\=\d\+\%(\.\d*\)\=\%([eE]_\=\d\+\)\=\%(\%(j\|a[dr]\)_\=\d\+\%(\.\d*\)\=\%([eE]_\=\d\+\)\=\)\=\%([px]_\=\d\+\%(\.\d*\)\=\%([eE]_\=\d\+\)\=\%(\%(j\|a[dr]\)_\=\d\+\%(\.\d*\)\=\%([eE]_\=\d\+\)\=\)\=\)\=/
syn match jNumber /\<_\=\d\+\%(\.\d*\)\=\%([eE]_\=\d\+\)\=r_\=\d\+\%(\.\d*\)\=\%([eE]_\=\d\+\)\=/
syn match jNumber /\<_\=\d\+\%([eE]\d\+\)\=b_\=[0-9a-z]\+/
syn match jNumber /\<__\=\>/
syn match jNumber /\<_\=\d\+x\>/

syn match jComment /NB\..*$/

hi def link jControl Statement
hi def link jString String
hi def link jNumber Number
hi def link jComment Comment

let b:current_syntax = "j"