shithub: femtolisp

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add the_empty_string to clean up the mess

--- a/builtins.c

+++ b/builtins.c

@@ -395,8 +395,6 @@

 	char *val = getenv(name);

 	if(val == nil)

 		return FL_f;

-	if(*val == 0)

-		return symbol_value(FL(emptystringsym));

 	return cvalue_static_cstring(val);

 }

--- a/cvalues.c

+++ b/cvalues.c

@@ -109,7 +109,7 @@

 	if(type->eltype == FL(bytetype)){

 		if(sz == 0)

-			return symbol_value(FL(emptystringsym));

+			return FL(the_empty_string);

 		sz++;

 		str = 1;

 	}

@@ -175,6 +175,8 @@

 value_t

 cvalue_string(size_t sz)

 {

+	if(sz == 0)

+		return FL(the_empty_string);

 	return cvalue(FL(stringtype), sz);

 }

@@ -181,6 +183,8 @@

 value_t

 cvalue_static_cstring(const char *str)

 {

+	if(*str == 0)

+		return FL(the_empty_string);

 	return cvalue_from_ref(FL(stringtype), (char*)str, strlen(str), FL_nil);

 }

@@ -1485,8 +1489,6 @@

 	FL(mpinttype)->vtable = &mpint_vtable;

 	FL(stringtype) = get_type(symbol_value(FL(stringtypesym)));

+	FL(the_empty_string) = cvalue_from_ref(FL(stringtype), (char*)"", 0, FL_nil);

 	FL(runestringtype) = get_type(symbol_value(FL(runestringtypesym)));

-

-	FL(emptystringsym) = symbol("*empty-string*", false);

-	set(FL(emptystringsym), cvalue_static_cstring(""));

 }

--- a/flisp.boot

+++ b/flisp.boot

@@ -14,8 +14,7 @@

 	      #fn("6000n201l:" #()) #fn("6000n201m:" #()) 0 #fn("8000z0700}2:" #(vector))

 	      #fn("8000z0700}2:" #(aset!)) 0 0 0 0 0 0 0 0 0 0 0 #fn("9000n3012082>1|:" #(#fn("6000n1A061:" #())))

 	      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 #fn("8000z0700}2:" #(aref)) 0 0)

-	    *empty-string* "" *properties*

-	    #table(*funvars* #table(length= (lst n)  help (term))  *doc* #table(length= "Bounded length test.\n\nUse this instead of (= (length lst) n), since it avoids unnecessary\nwork and always terminates."  help "Display documentation for the specified term, if available."  *properties* "All properties of symbols recorded with putprop are recorded in this table."))

+	    *properties* #table(*funvars* #table(length= (lst n)  help (term))  *doc* #table(length= "Bounded length test.\n\nUse this instead of (= (length lst) n), since it avoids unnecessary\nwork and always terminates."  help "Display documentation for the specified term, if available."  *properties* "All properties of symbols recorded with putprop are recorded in this table."))

 	    *runestring-type* (array rune) *string-type* (array byte)

 	    *syntax-environment* #table(when #fn(";000z1200211POe4:" #(if begin))  help #fn("<000n170021527002252853\\0738551474504863B07450475086P51@30O47450@B0732627051524745047860:" #(getprop

   *doc* *funvars* princ newline print "no help for " #fn(string) void))  with-output-to #fn("<000z12021e1220e2e1e12315163:" #(#fn(nconc)

--- a/flisp.c

+++ b/flisp.c

@@ -493,6 +493,7 @@

 	FL(lasterror) = relocate(FL(lasterror));

 	FL(memory_exception_value) = relocate(FL(memory_exception_value));

 	FL(the_empty_vector) = relocate(FL(the_empty_vector));

+	FL(the_empty_string) = relocate(FL(the_empty_string));

 	sweep_finalizers();

--- a/flisp.h

+++ b/flisp.h

@@ -388,6 +388,7 @@

 	value_t UnboundError;

 	value_t the_empty_vector;

+	value_t the_empty_string;

 	value_t memory_exception_value;

 	value_t tablesym;

@@ -401,7 +402,7 @@

 	value_t int64sym, uint64sym, bignumsym;

 	value_t longsym, ulongsym, bytesym, runesym;

 	value_t structsym, arraysym, enumsym, cfunctionsym, voidsym, pointersym;

-	value_t stringtypesym, runestringtypesym, emptystringsym;

+	value_t stringtypesym, runestringtypesym;

 	value_t unionsym, floatsym, doublesym;

 	htable_t TypeTable;

--- a/iostream.c

+++ b/iostream.c

@@ -393,6 +393,8 @@

 		ios_trunc(st, 0);

 	}else{

 		uint8_t *b = ios_takebuf(st, &n); n--;

+		if(n == 0)

+			return FL(the_empty_string);

 		b[n] = '\0';

 		str = cvalue_from_ref(FL(stringtype), b, n, FL_nil);

 		cv_autorelease(ptr(str));

@@ -406,7 +408,11 @@

 	ios_t *src = toiostream(args[0]);

 	if(src->bm != bm_mem)

 		lerrorf(FL(ArgError), "requires memory stream");

-	return stream_to_string(&args[0]);

+	bool eof = ios_eof(src);

+	value_t v = stream_to_string(&args[0]);

+	if(eof && v == FL(the_empty_string))

+		v = FL_eof;

+	return v;

 }

 void

--- a/string.c

+++ b/string.c

@@ -197,8 +197,6 @@

 		if(n != endchar)

 			bounds_error(args[0], args[2]);

 	}

-	if(endbytes == startbytes)

-		return symbol_value(FL(emptystringsym));

 	value_t ns = cvalue_string(endbytes-startbytes);

 	s = cvalue_data(args[0]); // reload after alloc

 	memmove(cvalue_data(ns), s+startbytes, endbytes-startbytes);