From 06a1d2e33d3186d01b07548b2b3f4c78de7e4b83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beno=C3=AEt=20Minisini?= <benoit.minisini@gambas-basic.org>
Date: Wed, 29 Mar 2023 12:16:47 +0200
Subject: [PATCH] 'Eval()' now can evaluate several expressions at once,
 provided that they are separated by newlines. The value of the last
 expression is returned.

[INTERPRETER]
* NEW: Support for the new Eval() feature.

[GB.EVAL]
* NEW: 'Eval()' now can evaluate several expressions at once, provided that they are separated by newlines. The value of the last expression is returned.
* NEW: 'Eval()' now returns NULL if its last expression returns nothing.
---
 main/gbx/gbx_exec_loop.c  |  7 +++++-
 main/lib/eval/eval.c      | 47 ++++++++++++++++++++++-----------------
 main/lib/eval/eval_read.c |  8 +++----
 main/lib/eval/eval_read.h |  4 ++--
 4 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/main/gbx/gbx_exec_loop.c b/main/gbx/gbx_exec_loop.c
index 38117cdd0..bf8e47ad5 100644
--- a/main/gbx/gbx_exec_loop.c
+++ b/main/gbx/gbx_exec_loop.c
@@ -1145,7 +1145,7 @@ _JUMP_IF_FALSE_FAST:
 _RETURN:
 
 	{
-		static const void *return_jump[] = { &&__RETURN_GOSUB, &&__RETURN_VALUE, &&__RETURN_VOID, &&__INIT_BYTECODE_CHECK };
+		static const void *return_jump[] = { &&__RETURN_GOSUB, &&__RETURN_VALUE, &&__RETURN_VOID, &&__INIT_BYTECODE_CHECK, &&__RETURN_VALUE_OR_VOID };
 
 		goto *return_jump[GET_UX()];
 
@@ -1171,6 +1171,11 @@ _RETURN:
 
 		goto _MAIN;
 
+	__RETURN_VALUE_OR_VOID:
+
+		if (SP[-1].type == T_VOID)
+			goto __RETURN_VOID;
+
 	__RETURN_VALUE:
 
 		VALUE_conv(&SP[-1], FP->type);
diff --git a/main/lib/eval/eval.c b/main/lib/eval/eval.c
index 8234f3634..1c64f1f55 100644
--- a/main/lib/eval/eval.c
+++ b/main/lib/eval/eval.c
@@ -136,9 +136,10 @@ void EVAL_start(EXPRESSION *expr)
 	}
 }
 
-bool EVAL_compile(EXPRESSION *expr, bool assign)
+bool EVAL_compile(EXPRESSION *expr, bool force_assign)
 {
 	bool error = FALSE;
+	bool assign;
 
 	EVAL = expr;
 
@@ -155,25 +156,33 @@ bool EVAL_compile(EXPRESSION *expr, bool assign)
 
 		EVAL->current = EVAL->pattern;
 
-		if (PATTERN_is(*EVAL->current, RS_LET))
+		for(;;)
 		{
-			EVAL->current++;
-			assign = TRUE;
+			if (PATTERN_is(*EVAL->current, RS_LET))
+			{
+				EVAL->current++;
+				assign = TRUE;
+			}
+			else
+				assign = force_assign;
+
+			if (assign)
+			{
+				if (!TRANS_affectation())
+					THROW(E_SYNTAX);
+			}
+			else
+				TRANS_expression();
+
+			if (PATTERN_is_end(*EVAL->current))
+			{
+				CODE_return(4);
+				break;
+			}
+			else
+				CODE_drop();
 		}
 
-		if (assign)
-		{
-			if (!TRANS_affectation())
-				THROW(E_SYNTAX);
-		}
-		else
-			TRANS_expression();
-
-		if (!PATTERN_is_end(*EVAL->current))
-			THROW(E_SYNTAX);
-
-		CODE_return(1);
-
 		EVAL->stack_usage = CODE_stack_usage;
 	}
 	CATCH
@@ -213,10 +222,8 @@ void EVAL_new(EXPRESSION **expr, char *src, int len)
 {
 	GB.Alloc((void **)expr, sizeof(EXPRESSION));
 	CLEAR(*expr);
-	(*expr)->source = GB.NewString(src, len);
-	(*expr)->source = GB.AddString((*expr)->source, "\n\0", 2);
+	(*expr)->source = GB.AddString(GB.NewString(src, len), "\n\0", 2);
 	(*expr)->len = len + 2;
-	/*(*expr)->option = option;*/
 }
 
 
diff --git a/main/lib/eval/eval_read.c b/main/lib/eval/eval_read.c
index 381797538..1a520dd75 100644
--- a/main/lib/eval/eval_read.c
+++ b/main/lib/eval/eval_read.c
@@ -34,7 +34,7 @@
 
 //#define DEBUG 1
 
-PUBLIC const char *READ_source_ptr;
+const char *READ_source_ptr;
 #define source_ptr READ_source_ptr
 
 static bool is_init = FALSE;
@@ -113,7 +113,7 @@ static bool _no_quote = FALSE;
 #define BUF_MAX 255
 static char _buffer[BUF_MAX + 1];
 
-PUBLIC char *READ_get_pattern(PATTERN *pattern)
+char *READ_get_pattern(PATTERN *pattern)
 {
 	int type = PATTERN_type(*pattern);
 	int index = PATTERN_index(*pattern);
@@ -177,7 +177,7 @@ PUBLIC char *READ_get_pattern(PATTERN *pattern)
 }
 
 #if DEBUG
-PUBLIC void READ_dump_pattern(PATTERN *pattern)
+void READ_dump_pattern(PATTERN *pattern)
 {
 	int type = PATTERN_type(*pattern);
 	int index = PATTERN_index(*pattern);
@@ -623,7 +623,7 @@ static void add_spaces()
 }
 
 
-PUBLIC void EVAL_read(void)
+void EVAL_read(void)
 {
 	static const void *jump_char[12] =
 	{
diff --git a/main/lib/eval/eval_read.h b/main/lib/eval/eval_read.h
index f4dec483c..adaf86655 100644
--- a/main/lib/eval/eval_read.h
+++ b/main/lib/eval/eval_read.h
@@ -30,7 +30,7 @@
 EXTERN const char *READ_source_ptr;
 #endif
 
-PUBLIC void EVAL_read(void);
-PUBLIC char *READ_get_pattern(PATTERN *pattern);
+void EVAL_read(void);
+char *READ_get_pattern(PATTERN *pattern);
 
 #endif