Antlr Parse Result Printer

antlr.sh

#!/bin/bash

############################################################################
## !! WARNING !! This script deletes .java files in the current directory ##
############################################################################

#
# Properties
#
ANTLR_JAR="antlr-4.4-complete.jar"
MD5=md5 # may be md5sum

#
# Function declarations
#
function execute() {
    eval "$*"
    if [ $? -ne 0 ] ; then
        exit 1
    fi
}

function cleanup() {
    GRAMMAR=$1
    rm -f ./"$GRAMMAR"*.java
    rm -f ./"$GRAMMAR"*.class
    rm -f ./"$GRAMMAR"*.tokens
    rm -f ./"$GRAMMAR"*.md5
}

function ensureExists() {
    FILE=$1
    if [ ! -f "$FILE" ] ; then
        echo "$FILE does not exist."
        exit 1
    fi
}

function hasChanged() {
    FILE=$1
    FILE_MD5="${FILE}.md5"
    if [ ! -f "$FILE_MD5" ] || [ "$(cat "$FILE_MD5")" != "$($MD5 "$FILE")" ] ; then
        return 0 # true(!)
    else
        return 1 # false(!)
    fi
}

function markNotChanged() {
    FILE=$1
    FILE_MD5="${FILE}.md5"
    $MD5 "$FILE" > "$FILE_MD5"
}

#
# Check arguments
#
if [ $# -eq 1 ] && [ "$1" == "clean" ] ; then

    echo "Cleaning all generated files..."
    cleanup ""
    
    exit 0

elif [ $# -eq 2 ] && [ "$1" == "clean" ] ; then

    GRAMMAR=$2
    GRAMMAR_FILE="${GRAMMAR}.g4"

    echo "Cleaning generated files of ${GRAMMAR_FILE}..."
    cleanup "$GRAMMAR"

    exit 0

elif [ $# -eq 2 ] || [ $# -eq 3 ] ; then

    GRAMMAR=$1
    GRAMMAR_FILE="${GRAMMAR}.g4"
    START_RULE=$2
    INPUT_FILENAME=$3

    ensureExists "$GRAMMAR_FILE"

    #
    # Download antlr4 jar if necessary
    #
    if [ ! -f "./${ANTLR_JAR}" ] ; then
        execute "curl -O http://www.antlr.org/download/${ANTLR_JAR}"
    fi

    #
    # Check for grammar changes
    #
    if hasChanged "$GRAMMAR_FILE" ; then
        echo "Generating ${GRAMMAR_FILE}..."
        cleanup "$GRAMMAR"
        execute "java -jar ${ANTLR_JAR} ${GRAMMAR_FILE}"
        execute "javac -cp ${ANTLR_JAR} ${GRAMMAR}*.java"
        markNotChanged "${GRAMMAR_FILE}"
    fi

    #
    # Parse input
    #
    if [ -z "$INPUT_FILENAME" ] ; then
        echo "Please enter input to be parsed and press <Ctrl>-D when finished."
    fi

    execute "java -cp .:${ANTLR_JAR} org.antlr.v4.runtime.misc.TestRig ${GRAMMAR} ${START_RULE} -tree ${INPUT_FILENAME}"

    exit 0

else

    echo "Usage:"
    echo "- run parser of MyGrammar            : run MyGrammar startRule [input filename]"
    echo "- clean generated files of MyGrammar : run clean MyGrammar"
    echo "- clean all generated files          : run clean"

    exit 1

fi

Example

$ alias antlr=./antlr.sh

$ antlr Issue118 start
Please enter input to be parsed and press <Ctrl>-D when finished.
a 1 b
<Ctrl>-D
(start a 1 b)

$ echo "a 1 b" > test.txt
$ antlr Issue118 start test.txt
(start a 1 b)

Issue118.g4

grammar Issue118;

start : ID | ID INT ID ;
ID : [a-z]+ ;
INT : [0-9]+ ;
WS : [ \r\n\t]+ -> skip ;