treewide: rework internal data type system

Instead of relying on json_object values internally, use custom types to
represent the different ucode value types which brings a number of
advantages compared to the previous approach:

 - Due to the use of tagged pointers, small integer, string and bool
   values can be stored directly in the pointer addresses, vastly
   reducing required heap memory

 - Ability to create circular data structures such as
   `let o; o = { test: o };`

 - Ability to register custom `tostring()` function through prototypes

 - Initial mark/sweep GC implementation to tear down circular object
   graphs on VM deinit

The change also paves the way for possible future extensions such as
constant variables and meta methods for custom ressource types.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 28 insertions, 27 deletions

diff --git a/lexer.c b/lexer.c
index 1fba88f..74e0c4d 100644
--- a/lexer.c
+++ b/lexer.c
@@ -32,9 +32,9 @@
 #define UC_LEX_CONTINUE_PARSING (void *)1
 
 struct keyword {
-	int type;
+	unsigned type;
 	const char *pat;
-	int plen;
+	unsigned plen;
 	union {
 		double d;
 		bool b;
@@ -42,12 +42,12 @@ struct keyword {
 };
 
 struct token {
-	int type;
+	unsigned type;
 	union {
 		uint32_t patn;
 		char pat[4];
 	};
-	int plen;
+	unsigned plen;
 	uc_token *(*parse)(uc_lexer *, bool);
 };
 
@@ -223,10 +223,10 @@ utf8enc(char **out, int *rem, int code)
 #define UT_LEX_MAX_TOKEN_LEN 3
 
 static uc_token *
-emit_op(uc_lexer *lex, uint32_t pos, int type, struct json_object *val)
+emit_op(uc_lexer *lex, uint32_t pos, int type, uc_value_t *uv)
 {
 	lex->curr.type = type;
-	lex->curr.val = val;
+	lex->curr.uv = uv;
 	lex->curr.pos = pos;
 
 	return &lex->curr;
@@ -257,7 +257,7 @@ lookbehind_to_text(uc_lexer *lex, uint32_t pos, int type, const char *strip_trai
 				lex->lookbehindlen--;
 		}
 
-		rv = emit_op(lex, pos, type, xjs_new_string_len(lex->lookbehind, lex->lookbehindlen));
+		rv = emit_op(lex, pos, type, ucv_string_new_length(lex->lookbehind, lex->lookbehindlen));
 
 		lookbehind_reset(lex);
 	}
@@ -360,7 +360,7 @@ parse_comment(uc_lexer *lex, bool no_regexp)
 	size_t elen;
 
 	if (!buf_remaining(lex))
-		return emit_op(lex, lex->lastoff, TK_ERROR, xjs_new_string("Unterminated comment"));
+		return emit_op(lex, lex->lastoff, TK_ERROR, ucv_string_new("Unterminated comment"));
 
 	if (!strcmp(tok->pat, "//")) {
 		end = "\n";
@@ -406,7 +406,7 @@ parse_string(uc_lexer *lex, bool no_regexp)
 	int code;
 
 	if (!buf_remaining(lex))
-		return emit_op(lex, lex->lastoff, TK_ERROR, xjs_new_string("Unterminated string"));
+		return emit_op(lex, lex->lastoff, TK_ERROR, ucv_string_new("Unterminated string"));
 
 	for (ptr = lex->bufstart; ptr < lex->bufend; ptr++) {
 		/* continuation of escape sequence */
@@ -461,7 +461,7 @@ parse_string(uc_lexer *lex, bool no_regexp)
 				case 'u':
 					if (lex->esclen < 5) {
 						if (!isxdigit(*ptr))
-							return emit_op(lex, lex->source->off + lex->esclen + 1, TK_ERROR, xjs_new_string("Invalid escape sequence"));
+							return emit_op(lex, lex->source->off + lex->esclen + 1, TK_ERROR, ucv_string_new("Invalid escape sequence"));
 
 						lex->esc[lex->esclen++] = *ptr;
 					}
@@ -513,7 +513,7 @@ parse_string(uc_lexer *lex, bool no_regexp)
 				case 'x':
 					if (lex->esclen < 3) {
 						if (!isxdigit(*ptr))
-							return emit_op(lex, lex->source->off + lex->esclen + 1, TK_ERROR, xjs_new_string("Invalid escape sequence"));
+							return emit_op(lex, lex->source->off + lex->esclen + 1, TK_ERROR, ucv_string_new("Invalid escape sequence"));
 
 						lex->esc[lex->esclen++] = *ptr;
 					}
@@ -564,7 +564,7 @@ parse_string(uc_lexer *lex, bool no_regexp)
 						       dec(lex->esc[3]);
 
 						if (code > 255)
-							return emit_op(lex, lex->source->off + lex->esclen + 1, TK_ERROR, xjs_new_string("Invalid escape sequence"));
+							return emit_op(lex, lex->source->off + lex->esclen + 1, TK_ERROR, ucv_string_new("Invalid escape sequence"));
 
 						append_utf8(lex, code);
 
@@ -585,7 +585,7 @@ parse_string(uc_lexer *lex, bool no_regexp)
 			rv = lookbehind_to_text(lex, lex->lastoff, TK_STRING, NULL);
 
 			if (!rv)
-				rv = emit_op(lex, lex->lastoff, TK_STRING, xjs_new_string_len("", 0));
+				rv = emit_op(lex, lex->lastoff, TK_STRING, ucv_string_new_length("", 0));
 
 			return rv;
 		}
@@ -685,10 +685,11 @@ parse_regexp(uc_lexer *lex, bool no_regexp)
 
 				len = xasprintf(&s, "%c%*s",
 					(is_reg_global << 0) | (is_reg_icase << 1) | (is_reg_newline << 2),
-					json_object_get_string_len(rv->val),
-					json_object_get_string(rv->val));
+					ucv_string_length(rv->uv),
+					ucv_string_get(rv->uv));
 
-				json_object_set_string_len(rv->val, s, len);
+				ucv_free(rv->uv, false);
+				rv->uv = ucv_string_new_length(s, len);
 				free(s);
 
 				rv->type = TK_REGEXP;
@@ -733,11 +734,11 @@ parse_label(uc_lexer *lex, bool no_regexp)
 
 				switch (word->type) {
 				case TK_DOUBLE:
-					rv = emit_op(lex, lex->source->off - word->plen, word->type, uc_double_new(word->d));
+					rv = emit_op(lex, lex->source->off - word->plen, word->type, ucv_double_new(word->d));
 					break;
 
 				case TK_BOOL:
-					rv = emit_op(lex, lex->source->off - word->plen, word->type, xjs_new_boolean(word->b));
+					rv = emit_op(lex, lex->source->off - word->plen, word->type, ucv_boolean_new(word->b));
 					break;
 
 				default:
@@ -806,19 +807,19 @@ parse_number(uc_lexer *lex, bool no_regexp)
 				d = -d;
 
 			if (e > lex->lookbehind && *e == 0)
-				rv = emit_op(lex, lex->source->off - (e - lex->lookbehind), TK_DOUBLE, uc_double_new(d));
+				rv = emit_op(lex, lex->source->off - (e - lex->lookbehind), TK_DOUBLE, ucv_double_new(d));
 			else
-				rv = emit_op(lex, lex->source->off - (lex->lookbehindlen - (e - lex->lookbehind) - 1), TK_ERROR, xjs_new_string("Invalid number literal"));
+				rv = emit_op(lex, lex->source->off - (lex->lookbehindlen - (e - lex->lookbehind) - 1), TK_ERROR, ucv_string_new("Invalid number literal"));
 		}
 		else if (*e == 0) {
 			if (tok->pat[0] == '-')
 				n = (errno == ERANGE) ? INT64_MIN : -n;
 
-			rv = emit_op(lex, lex->source->off - (e - lex->lookbehind), TK_NUMBER, xjs_new_int64(n));
+			rv = emit_op(lex, lex->source->off - (e - lex->lookbehind), TK_NUMBER, ucv_int64_new(n));
 			//OP(rv)->is_overflow = (errno == ERANGE);
 		}
 		else {
-			rv = emit_op(lex, lex->source->off - (lex->lookbehindlen - (e - lex->lookbehind) - 1), TK_ERROR, xjs_new_string("Invalid number literal"));
+			rv = emit_op(lex, lex->source->off - (lex->lookbehindlen - (e - lex->lookbehind) - 1), TK_ERROR, ucv_string_new("Invalid number literal"));
 		}
 
 		lookbehind_reset(lex);
@@ -1008,7 +1009,7 @@ lex_step(uc_lexer *lex, FILE *fp, bool no_regexp)
 
 			buf_consume(lex, lex->bufend - lex->bufstart);
 
-			return emit_op(lex, lex->lastoff, TK_ERROR, xjs_new_string("Unterminated template block"));
+			return emit_op(lex, lex->lastoff, TK_ERROR, ucv_string_new("Unterminated template block"));
 		}
 
 		break;
@@ -1059,7 +1060,7 @@ lex_step(uc_lexer *lex, FILE *fp, bool no_regexp)
 				if (tok->type == TK_LSTM || tok->type == TK_LEXP) {
 					buf_consume(lex, tok->plen);
 
-					return emit_op(lex, lex->source->off - tok->plen, TK_ERROR, xjs_new_string("Template blocks may not be nested"));
+					return emit_op(lex, lex->source->off - tok->plen, TK_ERROR, ucv_string_new("Template blocks may not be nested"));
 				}
 
 				/* found end of block */
@@ -1093,7 +1094,7 @@ lex_step(uc_lexer *lex, FILE *fp, bool no_regexp)
 
 		/* no token matched and we do have remaining data, junk */
 		if (buf_remaining(lex))
-			return emit_op(lex, lex->source->off, TK_ERROR, xjs_new_string("Unexpected character"));
+			return emit_op(lex, lex->source->off, TK_ERROR, ucv_string_new("Unexpected character"));
 
 		/* we're at eof, allow unclosed statement blocks */
 		if (lex->block == STATEMENTS) {
@@ -1103,7 +1104,7 @@ lex_step(uc_lexer *lex, FILE *fp, bool no_regexp)
 		}
 
 		/* premature EOF */
-		return emit_op(lex, lex->source->off, TK_ERROR, xjs_new_string("Unterminated template block"));
+		return emit_op(lex, lex->source->off, TK_ERROR, ucv_string_new("Unterminated template block"));
 
 
 	case UT_LEX_PARSE_TOKEN:
@@ -1188,7 +1189,7 @@ uc_lexer_next_token(uc_lexer *lex, bool no_regexp)
 }
 
 const char *
-uc_get_tokenname(int type)
+uc_get_tokenname(unsigned type)
 {
 	static char buf[sizeof("'endfunction'")];
 	size_t i;