From 7471093f67ed864467f4e4eeebe2179933f91253 Mon Sep 17 00:00:00 2001
From: Felix Van der Jeugt <felix.vanderjeugt@posteo.net>
Date: Fri, 4 Nov 2022 08:21:05 +0100
Subject: [PATCH] add null (NIL) and negative numbers

---
 json.c | 33 ++++++++++++++++++++++++---------
 json.h |  2 +-
 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/json.c b/json.c
index 7feb50b..530a725 100644
--- a/json.c
+++ b/json.c
@@ -6,6 +6,16 @@
 #include "sortedmap.h"
 #include "arraylist.h"
 
+Json * parse_null(FILE *stream) {
+	Json * json;
+	if (getc(stream) == 'u' && getc(stream) == 'l' && getc(stream) == 'l') {
+		json = malloc(sizeof(Json));
+		json->type = NIL;
+		return json;
+	}
+	return NULL;
+}
+
 Json * parse_true(FILE *stream) {
 	Json * json;
 	if (getc(stream) == 'r' && getc(stream) == 'u' && getc(stream) == 'e') {
@@ -28,7 +38,8 @@ Json * parse_false(FILE *stream) {
 	return NULL;
 }
 
-Json * parse_number(FILE *stream) {
+/* TODO: scientific notation */
+Json * parse_number(FILE *stream, int sign) {
 	Json * json;
 	long num = 0, den = 0;
 	char c;
@@ -58,12 +69,13 @@ Json * parse_number(FILE *stream) {
 			if (c != EOF) ungetc(c, stream);
 			json = malloc(sizeof(Json));
 			json->type = NUMBER;
-			json->value.number = num * 1.0 / den;
+			json->value.number = sign * num * 1.0 / den;
 			return json;
 		}
 	}
 }
 
+/* TODO: more escaped characters, unicode? */
 Json * parse_string(FILE *stream) {
 	int i = 0, cap = 10;
 	char * buffer = calloc(cap, sizeof(char));
@@ -71,7 +83,6 @@ Json * parse_string(FILE *stream) {
 	int escaped = 0;
 	Json * json;
 	while ((c = getc(stream)) != EOF) {
-		printf("char: %c, buffer: %s, i: %d\n", c, buffer, i);
 		switch (c) {
 		case '\\':
 			escaped = 1;
@@ -114,6 +125,10 @@ Json * json_parse(FILE *stream) {
 			return parse_true(stream);
 		case 'f':
 			return parse_false(stream);
+		case 'n':
+			return parse_null(stream);
+		case '-':
+			return parse_number(stream, -1);
 		case '0':
 		case '1':
 		case '2':
@@ -125,7 +140,7 @@ Json * json_parse(FILE *stream) {
 		case '8':
 		case '9':
 			ungetc(c, stream);
-			return parse_number(stream);
+			return parse_number(stream, 1);
 		case ' ':
 		case '\n':
 		case '\t':
@@ -152,6 +167,9 @@ void json_print(Json *this, FILE *stream) {
 	int i;
 	struct printacc acc = { NULL, 0 };
 	switch (this->type) {
+	case NIL:
+		fprintf(stream, "null");
+		break;
 	case BOOLEAN:
 		fprintf(stream, this->value.boolean == 0 ? "false" : "true");
 		break;
@@ -183,16 +201,13 @@ void json_print(Json *this, FILE *stream) {
 
 void json_free(Json *this) {
 	switch (this->type) {
+	case NIL:
 	case BOOLEAN:
-		/* TODO */
+	case NUMBER:
 		break;
 	case STRING:
-		/* TODO */
 		free(this->value.string);
 		break;
-	case NUMBER:
-		/* TODO */
-		break;
 	case LIST:
 		/* TODO */
 		break;
diff --git a/json.h b/json.h
index c868ac8..5bf3e28 100644
--- a/json.h
+++ b/json.h
@@ -2,7 +2,7 @@
 #define JSON_HEADER
 #include "sortedmap.h"
 #include "arraylist.h"
-enum jsontype { BOOLEAN, STRING, NUMBER, LIST, MAP };
+enum jsontype { NIL, BOOLEAN, STRING, NUMBER, LIST, MAP };
 
 typedef struct json {
 	enum jsontype type;