From e5d44899cffd80653da9e0336af36230c4e992a0 Mon Sep 17 00:00:00 2001
From: Charlie Stanton <charlie@shtanton.xyz>
Date: Sun, 9 Jan 2022 15:10:21 +0000
Subject: Add parsing numbers

---
 cudl.c    | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 cudl.h    |  1 +
 test.cudl |  5 +++++
 3 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/cudl.c b/cudl.c
index b596e92..b5022a7 100644
--- a/cudl.c
+++ b/cudl.c
@@ -5,6 +5,7 @@
 #include "cudl.h"
 
 #define STRIP_WHITESPACE(text) while (isspace(*(text))) (text)++
+
 #define IS_KEY_CHAR(c) (\
 	'a' <= (c) && (c) <= 'z' ||\
 	'A' <= (c) && (c) <= 'Z' ||\
@@ -12,6 +13,10 @@
 	(c) == '_' || (c) == '-'\
 )
 
+#define IS_DIGIT(c) (\
+	'0' <= (c) && (c) <= '9'\
+)
+
 int cudl_err = CUDL_OK;
 
 static char *fread_all(FILE *file) {
@@ -43,18 +48,26 @@ void cudl_debug(struct cudl_value value) {
 			else
 				printf("%%false");
 			break;
+		case CUDL_TAG_NUMBER:
+			printf("%lf", value.data.number);
+			break;
 		case CUDL_TAG_STRING:
 			printf("\"%s\"", value.data.string);
 			break;;
 		case CUDL_TAG_ARRAY:
 			printf("[");
-			for (i = 0; i < value.data.array.length; i++)
+			for (i = 0; i < value.data.array.length; i++) {
+				if (i != 0)
+					printf(" ");
 				cudl_debug(value.data.array.values[i]);
+			}
 			printf("]");
 			break;
 		case CUDL_TAG_MAP:
 			printf("{");
 			for (i = 0; i < value.data.map.length; i++) {
+				if (i != 0)
+					printf(" ");
 				printf("\"%s\": ", value.data.map.fields[i].key);
 				cudl_debug(value.data.map.fields[i].value);
 			}
@@ -106,11 +119,61 @@ static size_t parse_bool_or_null(char *input, struct cudl_value *value) {
 	return 0;
 }
 
+static size_t parse_number(char *input, struct cudl_value *value) {
+	double number;
+	size_t i, exponentStart;
+	int exponent, otherExponent;
+	int exponentUsed;
+	exponentUsed = 0;
+	number = 0;
+	i = input[0] == '-';
+	for (;; i++) {
+		if (IS_DIGIT(input[i])) {
+			number = number * 10 + (input[i] - '0');
+			exponent++;
+			continue;
+		} else if (input[i] == '.') {
+			exponent = 0;
+			exponentUsed = 1;
+			continue;
+		}
+		break;
+	}
+	if (input[0] == '-')
+		number = 0 - number;
+	if (!exponentUsed)
+		exponent = 0;
+	otherExponent = 0;
+	if (input[i] == 'e' && (IS_DIGIT(input[i+1]) || (input[i+1] == '-' && IS_DIGIT(input[i+2])))) {
+		i++;
+		exponentStart = i;
+		i += input[i] == '-';
+		for (;; i++) {
+			if (IS_DIGIT(input[i]))
+				otherExponent = otherExponent * 10 + (input[i] - '0');
+			else
+				break;
+		}
+		if (input[exponentStart] == '-')
+			otherExponent = 0 - otherExponent;
+	}
+	exponent = exponent - otherExponent;
+	for (; exponent > 0; exponent--) {
+		number /= 10;
+	}
+	for (; exponent < 0; exponent++) {
+		number *= 10;
+	}
+	value->tag = CUDL_TAG_NUMBER;
+	value->data.number = number;
+	return i;
+}
+
 /* Convert UCS character to utf-8 bytes.
  * Return number of bytes generated.
  * Sets cudl_error on error.
  * Shamelessly lifted from https://github.com/cktan/tomc99 */
-size_t cudl_ucs_to_utf8(int64_t ucs, char utf8[6]) {
+static size_t cudl_ucs_to_utf8(int64_t ucs, char utf8[6]) {
 	if (
 		0xd800 <= ucs && ucs <= 0xdfff ||
 		0xfffe <= ucs && ucs <= 0xffff ||
@@ -482,6 +545,8 @@ static size_t _parse_value(char *input, struct cudl_value *value) {
 		value->tag = CUDL_TAG_STRING;
 		return parse_quoted_string(++input, &value->data.string) + 1;
 	}
+	if (IS_DIGIT(*input) || *input == '-')
+		return parse_number(input, value);
 	cudl_err = CUDL_ERR_UNRECOGNISED_VALUE;
 	return 0;
 }
diff --git a/cudl.h b/cudl.h
index 36d2365..6f78909 100644
--- a/cudl.h
+++ b/cudl.h
@@ -33,6 +33,7 @@ struct cudl_map_field {
 enum {
 	CUDL_TAG_NULL,
 	CUDL_TAG_BOOL,
+	CUDL_TAG_NUMBER,
 	CUDL_TAG_ARRAY,
 	CUDL_TAG_MAP,
 	CUDL_TAG_STRING,
diff --git a/test.cudl b/test.cudl
index a9de397..b95e6be 100644
--- a/test.cudl
+++ b/test.cudl
@@ -4,6 +4,11 @@
 	[%null %null %false]
 	["hello\nfriend\t\tstuff\"" "world"]
 	"\U0001f600"
+	12
+	12.4
+	13.456
+	123.345e4
+	123456789e-8
 	{
 		testing: "this is a test map"
 		i_hope_it_works: {nesting: "nested maps!!!"}
-- 
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