small cleanup in BASIC

c64/basic/basic_commands/helper_load_fetch_filename.s

@@ -0,0 +1,41 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# *   BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Fetches file name, Carry set if not found
+//
+
+
+helper_load_fetch_filename:
+
+	// Check if end of statement
+
+	jsr end_of_statement_check
+	bcs !+
+
+	// Call the expression parser, make sure it returned a string
+
+	jsr FRMEVL
+
+	lda VALTYP
+	bpl_16 do_SYNTAX_error
+
+	// Set the filename address and pointer
+
+	lda __FAC1+0
+	sta FNLEN
+
+	lda __FAC1+1
+	sta FNADDR+0
+	lda __FAC1+2
+	sta FNADDR+1
+
+	// Mark success
+
+	clc
+
+	// FALLTROUGH
+
+!:
+	rts