implemented key/value hierarchy; added 2 examples; fixed some warnings in tests

Makefile

@@ -17,11 +17,19 @@ jsmn_test: jsmn_test.o
 
 jsmn_test.o: jsmn_test.c libjsmn.a
 
+simple_example: example/simple.o libjsmn.a
+	$(CC) $^ -o $@
+
+jsondump: example/jsondump.o libjsmn.a
+	$(CC) $^ -o $@
+
 clean:
-	rm -f jsmn.o jsmn_test.o
+	rm -f jsmn.o jsmn_test.o example/simple.o
 	rm -f jsmn_test
 	rm -f jsmn_test.exe
 	rm -f libjsmn.a
+	rm -f simple_example
+	rm -f jsondump
 
 .PHONY: all clean test
 

example/jsondump.c

@@ -0,0 +1,112 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include "../jsmn.h"
+
+/*
+ * An example of reading JSON from stdin and printing its content to stdout.
+ * The output looks like YAML, but I'm not sure if it's really compatible.
+ */
+
+static int dump(const char *js, jsmntok_t *t, size_t count, int indent) {
+	int i, j, k;
+	if (count == 0) {
+		return 0;
+	}
+	if (t->type == JSMN_PRIMITIVE) {
+		printf("%.*s", t->end - t->start, js+t->start);
+		return 1;
+	} else if (t->type == JSMN_STRING) {
+		printf("'%.*s'", t->end - t->start, js+t->start);
+		return 1;
+	} else if (t->type == JSMN_OBJECT) {
+		printf("\n");
+		j = 0;
+		for (i = 0; i < t->size; i++) {
+			for (k = 0; k < indent; k++) printf("  ");
+			j += dump(js, t+1+j, count-j, indent+1);
+			printf(": ");
+			j += dump(js, t+1+j, count-j, indent+1);
+			printf("\n");
+		}
+		return j+1;
+	} else if (t->type == JSMN_ARRAY) {
+		j = 0;
+		printf("\n");
+		for (i = 0; i < t->size; i++) {
+			for (k = 0; k < indent-1; k++) printf("  ");
+			printf("   - ");
+			j += dump(js, t+1+j, count-j, indent+1);
+			printf("\n");
+		}
+		return j+1;
+	}
+	return 0;
+}
+
+int main() {
+	int r;
+	int eof_expected = 0;
+	char *js = NULL;
+	size_t jslen = 0;
+	char buf[BUFSIZ];
+
+	jsmn_parser p;
+	jsmntok_t *tok;
+	size_t tokcount = 2;
+
+	/* Prepare parser */
+	jsmn_init(&p);
+
+	/* Allocate some tokens as a start */
+	tok = malloc(sizeof(*tok) * tokcount);
+	if (tok == NULL) {
+		fprintf(stderr, "malloc(): errno=%d\n", errno);
+		return 3;
+	}
+
+	for (;;) {
+		/* Read another chunk */
+		r = fread(buf, 1, sizeof(buf), stdin);
+		if (r < 0) {
+			fprintf(stderr, "fread(): %d, errno=%d\n", r, errno);
+			return 1;
+		}
+		if (r == 0) {
+			if (eof_expected != 0) {
+				return 0;
+			} else {
+				fprintf(stderr, "fread(): unexpected EOF\n");
+				return 2;
+			}
+		}
+
+		js = realloc(js, jslen + r + 1);
+		if (js == NULL) {
+			fprintf(stderr, "realloc(): errno=%d\n", errno);
+			return 3;
+		}
+		strncpy(js + jslen, buf, r);
+		jslen = jslen + r;
+
+again:
+		r = jsmn_parse(&p, js, jslen, tok, tokcount);
+		if (r < 0) {
+			if (r == JSMN_ERROR_NOMEM) {
+				tokcount = tokcount * 2;
+				tok = realloc(tok, sizeof(*tok) * tokcount);
+				if (tok == NULL) {
+					fprintf(stderr, "realloc(): errno=%d\n", errno);
+					return 3;
+				}
+				goto again;
+			}
+		} else {
+			dump(js, tok, p.toknext, 0);
+			eof_expected = 1;
+		}
+	}
+
+	return 0;
+}

example/simple.c

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <string.h>
+#include "../jsmn.h"
+
+/*
+ * A small example of jsmn parsing when JSON structure is known and number of
+ * tokens is predictable.
+ */
+
+const char *JSON_STRING =
+	"{\"user\": \"johndoe\", \"admin\": false, \"uid\": 1000,\n  "
+	"\"groups\": [\"users\", \"wheel\", \"audio\", \"video\"]}";
+
+static int jsoneq(const char *json, jsmntok_t *tok, const char *s) {
+	if (tok->type == JSMN_STRING && (int) strlen(s) == tok->end - tok->start &&
+			strncmp(json + tok->start, s, tok->end - tok->start) == 0) {
+		return 0;
+	}
+	return -1;
+}
+
+int main() {
+	int i;
+	int r;
+	jsmn_parser p;
+	jsmntok_t t[128]; /* We expect no more than 128 tokens */
+
+	jsmn_init(&p);
+	r = jsmn_parse(&p, JSON_STRING, strlen(JSON_STRING), t, sizeof(t)/sizeof(t[0]));
+	if (r < 0) {
+		printf("Failed to parse JSON: %d\n", r);
+		return 1;
+	}
+
+	/* Assume the top-level element is an object */
+	if (r < 1 || t[0].type != JSMN_OBJECT) {
+		printf("Object expected\n");
+		return 1;
+	}
+
+	/* Loop over all keys of the root object */
+	for (i = 1; i < r; i++) {
+		if (jsoneq(JSON_STRING, &t[i], "user") == 0) {
+			/* We may use strndup() to fetch string value */
+			printf("- User: %.*s\n", t[i+1].end-t[i+1].start,
+					JSON_STRING + t[i+1].start);
+			i++;
+		} else if (jsoneq(JSON_STRING, &t[i], "admin") == 0) {
+			/* We may additionally check if the value is either "true" or "false" */
+			printf("- Admin: %.*s\n", t[i+1].end-t[i+1].start,
+					JSON_STRING + t[i+1].start);
+			i++;
+		} else if (jsoneq(JSON_STRING, &t[i], "uid") == 0) {
+			/* We may want to do strtol() here to get numeric value */
+			printf("- UID: %.*s\n", t[i+1].end-t[i+1].start,
+					JSON_STRING + t[i+1].start);
+			i++;
+		} else if (jsoneq(JSON_STRING, &t[i], "groups") == 0) {
+			int j;
+			printf("- Groups:\n");
+			if (t[i+1].type != JSMN_ARRAY) {
+				continue; /* We expect groups to be an array of strings */
+			}
+			for (j = 0; j < t[i+1].size; j++) {
+				jsmntok_t *g = &t[i+j+2];
+				printf("  * %.*s\n", g->end - g->start, JSON_STRING + g->start);
+			}
+			i += t[i+1].size + 1;
+		} else {
+			printf("Unexpected key: %.*s\n", t[i].end-t[i].start,
+					JSON_STRING + t[i].start);
+		}
+	}
+	return 0;
+}

jsmn.c

@@ -234,7 +234,28 @@ jsmnerr_t jsmn_parse(jsmn_parser *parser, const char *js, size_t len,
 				if (parser->toksuper != -1 && tokens != NULL)
 					tokens[parser->toksuper].size++;
 				break;
-			case '\t' : case '\r' : case '\n' : case ':' : case ',': case ' ': 
+			case '\t' : case '\r' : case '\n' : case ' ': 
+				break;
+			case ':':
+				parser->toksuper = parser->toknext - 1;
+				break;
+			case ',':
+				if (tokens != NULL &&
+						tokens[parser->toksuper].type != JSMN_ARRAY &&
+						tokens[parser->toksuper].type != JSMN_OBJECT) {
+#ifdef JSMN_PARENT_LINKS
+					parser->toksuper = tokens[parser->toksuper].parent;
+#else
+					for (i = parser->toknext - 1; i >= 0; i--) {
+						if (tokens[i].type == JSMN_ARRAY || tokens[i].type == JSMN_OBJECT) {
+							if (tokens[i].start != -1 && tokens[i].end == -1) {
+								parser->toksuper = i;
+								break;
+							}
+						}
+					}
+#endif
+				}
 				break;
 #ifdef JSMN_STRICT
 			/* In strict mode primitives are: numbers and booleans */

jsmn_test.c

@@ -112,11 +112,11 @@ int test_simple() {
 }
 
 int test_primitive() {
+#ifndef JSMN_STRICT
 	int r;
 	jsmn_parser p;
 	jsmntok_t tok[10];
 	const char *js;
-#ifndef JSMN_STRICT
 	js = "\"boolVar\" : true";
 	jsmn_init(&p);
 	r = jsmn_parse(&p, js, strlen(js), tok, 10);
@@ -320,7 +320,6 @@ int test_array_nomem() {
 }
 
 int test_objects_arrays() {
-	int i;
 	int r;
 	jsmn_parser p;
 	jsmntok_t tokens[10];
@@ -350,7 +349,6 @@ int test_objects_arrays() {
 }
 
 int test_issue_22() {
-	int i;
 	int r;
 	jsmn_parser p;
 	jsmntok_t tokens[128];