Implement uxntal lambdas.

asm.doc

@@ -88,6 +88,12 @@ The following standard tokens are available:
  characters without any opcodes or delimiters. (If you need spaces, then
  you must use separate tokens such as 20 for spaces.)
 
+ { and } can be used around a lambda block (they can also be used for
+ macros as described above). The { represents a JSI to the matching } and
+ the } represents a STH2r instruction. In this way, the { } block is
+ skipped and the address of the beginning of the block (after the JSI
+ instruction) will be stored on the stack.
+
  An instruction opcode consists of three uppercase letters, optionally
  followed by any combination of instruction flags which can be "2" for
  16-bit operands, "r" to work with the other stack, and/or "k" to keep

uxnasm.c

@@ -59,13 +59,15 @@ typedef struct {
 
 typedef struct {
 	Uint8 data[LENGTH];
+	Uint8 lambda_stack[256], lambda_ptr, lambda_count;
 	unsigned int ptr, length;
 	Uint16 llen, mlen, rlen, xlen;
 	Label labels[MAXLABELS];
 	Macro macros[MAXMACROS];
 	Reference refs[MAXREFS];
 	ExpItem exps[MAXEXPS];
 	char scope[0x40];
+	char lambda[0x10];
 	Uint32 total;
 } Program;
 
@@ -228,6 +230,13 @@ makereference(char *scope, char *label, Uint16 addr)
 	return 1;
 }
 
+static char*makelambda(int id) {
+	scpy("?lambda", p.lambda, 8);
+	p.lambda[7] = '0' + (id >> 0x4);
+	p.lambda[8] = '0' + (id & 0xf);
+	return p.lambda;
+}
+
 static int makeexp(Uint8 kind,char*name,Uint32 len,Uint8 misc) {
   ExpItem*e;
   if(p.xlen==MAXEXPS) return error("Expansion limit exceeded","");
@@ -548,6 +557,13 @@ parse(char *w, FILE *f)
 		if(!makeexp('^',w+1,0,0)) return 0;
 		p.exps[p.xlen-1].len=p.ptr;
 		break;
+	case '{': /* lambda start */
+		p.lambda_stack[p.lambda_ptr++] = p.lambda_count;
+		makereference(p.scope, makelambda(p.lambda_count++), p.ptr + 1);
+		return writebyte(0x60) && writeshort(0xffff, 0);
+	case '}': /* lambda end */
+		if(!makelabel(makelambda(p.lambda_stack[--p.lambda_ptr])+1)) return error("Invalid label", w);
+		return writebyte(0x6f);
 	case '[':
 	case ']':
 		if(slen(w) == 1) break;