From 1ad6779aa4ff13ea00bcfe6320c4d9af1326a982 Mon Sep 17 00:00:00 2001
From: hyung-hwan <hyunghwan.chung@gmail.com>
Date: Thu, 3 Aug 2023 22:34:43 +0900
Subject: [PATCH] a bit of progress  in writing the evaluator function

---
 interp/eval.go | 61 +++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 50 insertions(+), 11 deletions(-)

diff --git a/interp/eval.go b/interp/eval.go
index ad14c3b..50b22c8 100644
--- a/interp/eval.go
+++ b/interp/eval.go
@@ -31,6 +31,7 @@ func (p *process_t) push_cnode_value(val *Cnode_t) error {
 	p.vstack[p.vsp] = unsafe.Pointer(uintptr(unsafe.Pointer(val)) | 1)
 	p.vsp++
 	p.ctx.count++
+	fmt.Printf("push_cnode_value = ctx.count => %d\n", p.ctx.count)
 
 	return nil
 }
@@ -43,7 +44,7 @@ func (p *process_t) push_string_value(val string) error {
 	p.vstack[p.vsp] = unsafe.Pointer(&val)
 	p.vsp++
 	p.ctx.count++
-
+	fmt.Printf("push_string_value = ctx.count => %d\n", p.ctx.count)
 	return nil
 }
 
@@ -58,6 +59,7 @@ func (p *process_t) merge_top_values() error {
 	p.vstack[p.vsp] = nil
 	p.vstack[p.vsp-1] = unsafe.Pointer(&new_val)
 	p.ctx.count--
+	fmt.Printf("merge_top_values = ctx.count => %d\n", p.ctx.count)
 	return nil
 }
 
@@ -124,7 +126,7 @@ func (p *process_t) pop_context(clear_vstack bool) (*Cnode_t, *Cnode_t) {
 	node = p.ctx.parent_node
 	container = p.ctx.container_node
 
-	if clear_vstack {
+	if clear_vstack { // TODO: use the conttext type instead... may be able to use container_node.code???
 		// clean up the unused part of the stack
 		for i = 1; i < p.ctx.count; i++ {
 			p.vstack[p.vsp-p.ctx.count+i] = nil
@@ -135,9 +137,9 @@ func (p *process_t) pop_context(clear_vstack bool) (*Cnode_t, *Cnode_t) {
 	}
 	p.ctx = p.ctx.parent_ctx
 
-	if p.ctx != nil {
-		p.ctx.count++ // let the return value be the argument to the caller
-	}
+//	if p.ctx != nil {
+//		p.ctx.count++ // let the return value be the argument to the caller
+//	}
 
 	return node, container
 }
@@ -205,7 +207,7 @@ func (interp *Interp) eval_stmt_nodes(container_node *Cnode_t) (*string, error)
 			panic("internal error - not statement node")
 		}
 
-		//fmt.Printf("PUSHING CONTEXT.....\n")
+		fmt.Printf("PUSHING CONTEXT.....\n")
 		p.push_context(stmt_node, upper_node)
 		p.push_string_value("") // placeholder for return value
 
@@ -225,6 +227,7 @@ func (interp *Interp) eval_stmt_nodes(container_node *Cnode_t) (*string, error)
 						fmt.Printf("\n--\n")
 					}
 					goto start_over_0
+
 				} else {
 					// no statements inside []. treat it like an empty string
 					p.push_string_value("")
@@ -232,7 +235,7 @@ func (interp *Interp) eval_stmt_nodes(container_node *Cnode_t) (*string, error)
 
 			case CNODE_DQUOTE:
 				if inner_node.child != nil {
-					//fmt.Printf("PUSHING CONTEXT.....\n")
+					fmt.Printf("PUSHING CONTEXT.....\n")
 					p.push_context(stmt_node, inner_node)
 					//p.push_string_value("") // no placeholder for return value is needed
 					inner_node = inner_node.child
@@ -284,22 +287,58 @@ func (interp *Interp) eval_stmt_nodes(container_node *Cnode_t) (*string, error)
 			is_stmt = false
 		}
 
-		//fmt.Printf("POPPING CONTEXT.....is_stmt[%v]\n", is_stmt)
+		fmt.Printf("POPPING CONTEXT.....is_stmt[%v]\n", is_stmt)
 		stmt_node, upper_node = p.pop_context(is_stmt)
 		if upper_node != container_node {
 			if debug {
 				fmt.Printf("resuming... %d upper_node.next %p\n", p.vsp, upper_node.next)
 			}
-			inner_node = upper_node.next // as if it hit the bottom of the innner for loop
-			goto resume
+
+			if upper_node.code != CNODE_BRACKET {
+				inner_node = upper_node.next // as if it hit the bottom of the innner for loop
+				p.ctx.count++; // use return value  on the stack as an argument
+				goto resume
+			}
 		}
 
 		//fmt.Printf("POPPING VALUE...\n")
+		/*v = (*string)(p.pop_value()) // get the return value of the statement.
+		if debug {
+			interp.dump_vstack(&p)
+		}*/
+		stmt_node = stmt_node.next
+
+		if stmt_node == nil {
+			// go doesn't allow jumping into a block.
+			// let's the put the code here
+			if upper_node != container_node {
+				// the upper node is not the top containing node passed to this function.
+				// the contenxt stack must not be empty in this case.
+				if upper_node.code != CNODE_BRACKET {
+					panic("internal error - invalid cnode type in the context statck")
+				}
+				fmt.Printf("POPPING CONTEXT.....false\n")
+				//stmt_node, upper_node = p.pop_context(false)
+				inner_node = upper_node.next
+				fmt.Printf(">>>>>>>>>>>>>>>>>> vsp %d ctx.count %d\n", p.vsp, p.ctx.count)
+
+				p.ctx.count++; // use the result value as an argument
+				goto resume
+			}
+
+			fmt.Printf("POPVAL...\n")
+			v = (*string)(p.pop_value()) // get the return value of the statement.
+			if debug {
+				interp.dump_vstack(&p)
+			}
+			break
+		}
+
+		fmt.Printf("POPVAL...\n")
 		v = (*string)(p.pop_value()) // get the return value of the statement.
 		if debug {
 			interp.dump_vstack(&p)
 		}
-		stmt_node = stmt_node.next
 	}
 
 	if debug {