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

# functions
s/@\(rcexpr\)@\([	 ]*(\)/@\10@\2/g
s/@\(error\)@\([	 ]*(\)/@\10@\2/g
s/@\(pswitch\)@\([	 ]*(\)/@\10@\2/g
s/@\(cbranch\)@\([	 ]*(\)/@\10@\2/g
s/@\(label\)@\([	 ]*(\)/@\10@\2/g
s/@\(branch\)@\([	 ]*(\)/@\10@\2/g
s/@\(werror\)@\([	 ]*(\)/@\10@\2/g
s/@\(decref\)@\([	 ]*(\)/@\10@\2/g
s/@\(incref\)@\([	 ]*(\)/@\10@\2/g

# variables
s/@\(opdope\)@/@\10@/g
s/@\(isn\)@/@\10@/g

# values
s/@\(TNULL\)@/@\10@/g

# types
s/@\(struct@[	 ]*@tnode\)@/@\10@/g
s/@\(struct@[	 ]*@cnode\)@/@\10@/g
s/@\(struct@[	 ]*@lnode\)@/@\10@/g
s/@\(struct@[	 ]*@fnode\)@/@\10@/g
s/@\(union@[	 ]*@tree\)@/@\10@/g

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