FEAT: implemented transcode/line for getting information about number of lines scanned

related to: Oldes/Rebol-issues#2302

Author: Oldes

src/boot/natives.reb

@@ -658,6 +658,8 @@ transcode: native [
 	/one  "Translate next complete value (returns the value only)"
 	/only "Translate only a single value (blocks dissected)"
 	/error "Do not cause errors - return error object as value in place"
+	/line  "Return also information about number of lines scaned"
+	 count [integer!] "Initial line number"
 ]
 
 echo: native [

src/core/l-scan.c

@@ -1896,6 +1896,8 @@ extern REBSER *Scan_Full_Block(SCAN_STATE *scan_state, REBYTE mode_char);
 	REBOOL one   = D_REF(3);
 	REBOOL only  = D_REF(4);
 	REBOOL relax = D_REF(5);
+	REBOOL line  = D_REF(6);
+	REBVAL *count = D_ARG(7);
 	REBSER *blk;
 	REBSER *ser;
 	REBYTE *bin;
@@ -1917,7 +1919,10 @@ extern REBSER *Scan_Full_Block(SCAN_STATE *scan_state, REBYTE mode_char);
 	if (next || one) SET_FLAG(scan_state.opts, SCAN_NEXT);
 	if (only)  SET_FLAG(scan_state.opts, SCAN_ONLY);
 	if (relax) SET_FLAG(scan_state.opts, SCAN_RELAX);
-	
+	if (line) {
+		if (0 >= VAL_INT64(count)) Trap1(RE_OUT_OF_RANGE, count);
+		scan_state.line_count = VAL_UNT32(count);
+	}
 	// Scan_Code clears the next flag!
 	// Decide if result should contain also modified input position.
 	// (with refinements /next, /only and /error)
@@ -1957,6 +1962,10 @@ extern REBSER *Scan_Full_Block(SCAN_STATE *scan_state, REBYTE mode_char);
 			VAL_INDEX(src) = len;
 		}
 		Append_Val(blk, src);
+		if (line) {
+			SET_INTEGER(count, scan_state.line_count);
+			Append_Val(blk, count);
+		}
 	}
 	return R_RET;
 }

src/tests/units/lexer-test.r3

@@ -35,6 +35,19 @@ Rebol [
 		--assert 1     = transcode/one "1 2"
 		--assert [1 2] = transcode/one "[1 2]"
 
+	--test-- "transcode/line"
+		--assert all [error? e: try [transcode "1 1d"] e/near = "(line 1) 1 1d"]
+		--assert all [error? e: try [transcode "1^/1d"] e/near = "(line 2) 1d"]
+		--assert all [error? e: try [transcode/line "1 1d" 10] e/near = "(line 10) 1 1d"]
+		--assert all [error? e: try [transcode/line "1^/1d" 10] e/near = "(line 11) 1d"]
+		--assert all [
+			code: "1^/2" line: 1
+			set [value code line] transcode/next/line :code :line
+			value = 1 line = 1
+			set [value code line] transcode/next/line :code :line
+			value = 2 line = 2
+		]
+
 ===end-group===
 
 ===start-group=== "Invalid construction"