s/@/ATSIGN/g
s/^/@/
s/$/@/
s/[^A-Za-z0-9_]\+/@&@/g

# functions
s/@\(rcexpr\)@\([	 ]*(\)/@\11@\2/g
s/@\(error\)@\([	 ]*(\)/@\11@\2/g
s/@\(pswitch\)@\([	 ]*(\)/@\11@\2/g
s/@\(cbranch\)@\([	 ]*(\)/@\11@\2/g
s/@\(label\)@\([	 ]*(\)/@\11@\2/g
s/@\(branch\)@\([	 ]*(\)/@\11@\2/g
s/@\(werror\)@\([	 ]*(\)/@\11@\2/g
s/@\(decref\)@\([	 ]*(\)/@\11@\2/g
s/@\(incref\)@\([	 ]*(\)/@\11@\2/g

# variables
s/@\(opdope\)@/@\11@/g
s/@\(isn\)@/@\11@/g

# values
s/@\(TNULL\)@/@\11@/g

# types
s/@\(struct@[	 ]*@tnode\)@/@\11@/g
s/@\(struct@[	 ]*@\)tname@/@\1nnode1@/g
s/@\(struct@[	 ]*@\)xtname@/@\1xnode1@/g
s/@\(struct@[	 ]*@\)tconst@/@\1cnode1@/g
s/@\(struct@[	 ]*@\)lconst@/@\1lnode1@/g
s/@\(struct@[	 ]*@\)ftconst@/@\1fnode1@/g
s/@\(union@[	 ]*@tree\)@/@\11@/g

s/@//g
s/ATSIGN/@/g