Flat: Adjust processing of command-line options
Change the way we process command line options to the flat command to
prepare for more flexibility. The usage remains the same.
diff --git a/experiments/flat/src/flat.c b/experiments/flat/src/flat.c
index ee3c2bb..af69d83 100644
--- a/experiments/flat/src/flat.c
+++ b/experiments/flat/src/flat.c
@@ -44,106 +44,131 @@
return data;
}
-static Grammar *grammarFromFile(const char *filename)
+static Grammar *grammarFromStr(Grammar *flatGrammar, const char *filename, const char *input)
{
- char *input = readStringFromFile(filename);
- if (input == NULL) {
- perror(filename);
- exit(1);
- }
-
- Grammar *flatGrammar = GrammarNewBuiltin();
Term *term = parse(flatGrammar,"Grammar",input,0,strlen(input));
if (term == NULL) {
fprintf(stderr,"%s: Parse failed\n",filename);
exit(1);
}
- Grammar *builtGrammar = grammarFromTerm(term,input);
+ return grammarFromTerm(term,input);
+}
- free(input);
- GrammarFree(flatGrammar);
+void usage(void)
+{
+ printf("Usage:\n"
+ "\n"
+ "flat -g\n"
+ "\n"
+ " Print the built-in PEG grammar\n"
+ "\n"
+ "flat -p FILENAME\n"
+ "\n"
+ " Parse FILENAME using the built-in PEG grammar, and print out the resulting\n"
+ " parse tree\n"
+ "\n"
+ "flat -b FILENAME\n"
+ "\n"
+ " Parse FILENAME using the built-in PEG grammar, then use the resulting parse\n"
+ " tree to build a Grammar object, and print out the constructed grammar.\n"
+ "\n"
+ "flat GRAMMAR INPUT\n"
+ "\n"
+ " Use the grammar defined in file GRAMMAR to parse the file INPUT, and print\n"
+ " out the resulting parse tree\n"
+ "\n");
+ exit(1);
+}
- return builtGrammar;
+char *maybeReadFile(const char *filename)
+{
+ if (filename == NULL)
+ return NULL;
+ char *str = readStringFromFile(filename);
+ if (str == NULL) {
+ perror(filename);
+ exit(1);
+ }
+ return str;
}
int main(int argc, const char **argv)
{
+ const char *grammarFilename = NULL;
+ const char *inputFilename = NULL;
+ char *grammarStr = NULL;
+ char *inputStr = NULL;
+ int useBuiltinGrammar = 0;
+ int showGrammar = 0;
+ Grammar *builtGrammar = NULL;
+ Term *inputTerm = NULL;
if ((argc == 2) && !strcmp(argv[1],"-g")) {
- // Build and print out the built-in PEG grammar
- Grammar *gram = GrammarNewBuiltin();
- GrammarPrint(gram);
- GrammarFree(gram);
+ useBuiltinGrammar = 1;
+ showGrammar = 1;
}
else if ((argc == 3) && !strcmp(argv[1],"-p")) {
- const char *filename = argv[2];
- char *input = readStringFromFile(filename);
- if (input == NULL) {
- perror(filename);
- exit(1);
- }
- Grammar *gram = GrammarNewBuiltin();
- Term *term = parse(gram,"Grammar",input,0,strlen(input));
- if (term == NULL) {
- fprintf(stderr,"%s: Parse failed\n",filename);
- exit(1);
- }
- TermPrint(term,input,"");
- free(input);
- GrammarFree(gram);
+ useBuiltinGrammar = 1;
+ inputFilename = argv[2];
}
else if ((argc == 3) && !strcmp(argv[1],"-b")) {
- Grammar *built = grammarFromFile(argv[2]);
- GrammarPrint(built);
- GrammarFree(built);
+ grammarFilename = argv[2];
+ showGrammar = 1;
}
else if (argc == 3) {
- const char *grammarFilename = argv[1];
- const char *inputFilename = argv[2];
+ grammarFilename = argv[1];
+ inputFilename = argv[2];
+ }
+ else {
+ usage();
+ }
- char *inputStr = readStringFromFile(inputFilename);
- if (inputStr == NULL) {
- perror(inputFilename);
+ Grammar *flatGrammar = GrammarNewBuiltin();
+
+ inputStr = maybeReadFile(inputFilename);
+ grammarStr = maybeReadFile(grammarFilename);
+
+ if (grammarStr != NULL) {
+ builtGrammar = grammarFromStr(flatGrammar,grammarFilename,grammarStr);
+ if (builtGrammar == NULL) {
+ fprintf(stderr,"Cannot build grammar\n");
exit(1);
}
+ }
- Grammar *builtGrammar = grammarFromFile(grammarFilename);
- const char *firstRuleName = GrammarFirstRuleName(builtGrammar);
- Term *inputTerm = parse(builtGrammar,firstRuleName,inputStr,0,strlen(inputStr));
+ Grammar *useGrammar = NULL;
+
+ if (useBuiltinGrammar)
+ useGrammar = flatGrammar;
+ else if (builtGrammar != NULL)
+ useGrammar = builtGrammar;
+ else
+ usage();
+
+ if (inputStr != NULL) {
+ const char *firstRuleName = GrammarFirstRuleName(useGrammar);
+ inputTerm = parse(useGrammar,firstRuleName,inputStr,0,strlen(inputStr));
if (inputTerm == NULL) {
fprintf(stderr,"%s: Parse failed\n",inputFilename);
exit(1);
}
- TermPrint(inputTerm,inputStr,"");
+ }
- free(inputStr);
- GrammarFree(builtGrammar);
+ if (showGrammar) {
+ GrammarPrint(useGrammar);
+ }
+ else if (inputTerm != NULL) {
+ TermPrint(inputTerm,inputStr,"");
}
else {
- printf("Usage:\n"
- "\n"
- "flat -g\n"
- "\n"
- " Print the built-in PEG grammar\n"
- "\n"
- "flat -p FILENAME\n"
- "\n"
- " Parse FILENAME using the built-in PEG grammar, and print out the resulting\n"
- " parse tree\n"
- "\n"
- "flat -b FILENAME\n"
- "\n"
- " Parse FILENAME using the built-in PEG grammar, then use the resulting parse\n"
- " tree to build a Grammar object, and print out the constructed grammar.\n"
- "\n"
- "flat GRAMMAR INPUT\n"
- "\n"
- " Use the grammar defined in file GRAMMAR to parse the file INPUT, and print\n"
- " out the resulting parse tree\n"
- "\n");
-
- return 1;
+ usage();
}
+
+ free(grammarStr);
+ free(inputStr);
+ GrammarFree(flatGrammar);
+ if (builtGrammar != NULL)
+ GrammarFree(builtGrammar);
return 0;
}
