bash lisp tokenizer NOTE: doesn't handle \" within strings yet

tokenizer.sh

#!/bin/bash

wholefile=$(cat $1)
filelen=${#wholefile}

idx=0
chunk=0
chunksz=500
while true; do
    if (( ${#str} < ( chunksz / 2) )) && (( chunk < filelen )); then
        str="${str}${wholefile:${chunk}:${chunksz}}"
        chunk=$(( chunk + ${chunksz} ))
    fi
    (( ${#str} == 0 )) && break
    [[ "${str}" =~ ^(\"[^\"]+\")|^([\(\)])|^([^ \"\(\)]+)|^[[:space:]]+ ]]
    match=${BASH_REMATCH[0]}
    str="${str:${#match}}"
    [ -n "${match# }" ] && echo "${match}"
    if [ -z "${BASH_REMATCH[0]}" ]; then
        echo >&2 "Error at: ${str:0:50}"
        exit 2
    fi
done

# much faster:
# sed 's/\("[^"][^"]*"\)\|\([()]\)\|\([^ "()][^ "()]*\)\|  */<\1.\2.\3>\n/g' $1