Add support for \ new line skips in BNFLexer

Author: MightyHelper

src/main/java/ko/carbonel/compiler/stream/lexer/bnf/BNFLexer.java

@@ -40,10 +40,18 @@ protected BNFLexerToken getNext() {
 			case "/" -> lexSlashOrComment();
 			case "{" -> lexAttributeCode();
 			case " " -> next();
+			case "\\" -> skipNewLine();
 			default -> lexNonTerminal();
 		};
 	}
 
+	private BNFLexerToken skipNewLine() {
+		FileLocation location = reader.getLocation();
+		reader.get();
+		if (!Objects.equals(reader.get(), "\n")) throw new LexerError(location, "Expected '\\n'");
+		return getNext();
+	}
+
 	private BNFLexerToken lexAttributeCode() {
 		final boolean[] found = {false};
 		return genericLexByArrayFunc(symbol -> {

src/test/resources/syntax/main_attr.bnf

@@ -17,7 +17,7 @@ ExpAdRF ::= ExpAdR | "λ"
 ExpAdR ::= OpAd ExpMul ExpAdRF
 ExpAd ::= ExpMul ExpAdRF
 ExpAndF ::= ExpAndR | "λ"
-ExpAndR ::= "&&" {st.expWrapBin(List.of("&&"))} ExpEq ExpAndF
+ExpAndR ::= "&&" {st.expWrapBin(List.of(v_0))} ExpEq ExpAndF
 ExpAnd ::= ExpEq ExpAndF
 ExpEqRF ::= ExpEqR | "λ"
 ExpEqR ::= OpEq {st.expWrapBin(v_0)} ExpRel ExpEqRF
@@ -26,7 +26,7 @@ ExpMulF ::= ExpMulR | "λ"
 ExpMulR ::= OpMul ExpUn ExpMulF
 ExpMul ::= ExpUn ExpMulF
 ExpOrF ::= ExpOrR | "λ"
-ExpOrR ::= "||" {st.expWrapBin(List.of("||"))} ExpAnd ExpOrF
+ExpOrR ::= "||" {st.expWrapBin(List.of(v_0))} ExpAnd ExpOrF
 ExpOr ::= ExpAnd ExpOrF
 ExpRelF ::= OpRel {st.expWrapBin(v_0)} ExpAd | "λ"
 ExpRel ::= ExpAd ExpRelF
@@ -68,7 +68,13 @@ StmtFFF ::= "λ" | "ELSE" {st.ifElse()} Stmt
 StmtF ::= ";" | ExpOr ";"
 Stmt_starF ::= Stmt_star | "λ"
 Stmt_star ::= Stmt Stmt_starF
-Stmt ::= "{" MethodF | {st.newIf()} "IF" "(" ExpOr ")" {st.ifBlock()} Stmt StmtFFF {st.end()} | {st.newReturn()} "RETURN" StmtF {st.end()} | {st.newEmpty()} ";" {st.end()} | {st.newAssign()} Assign ";" {st.end()} | {st.newExpr()} "(" ExpOr ")" ";" {st.end()} | {st.newWhile()} "WHILE" "(" ExpOr ")"{st.whileBody()} Stmt {st.end()}
+Stmt ::= "{" MethodF \
+| {st.newIf()} "IF" "(" ExpOr ")" {st.ifBlock()} Stmt StmtFFF {st.end()} \
+| {st.newReturn()} "RETURN" StmtF {st.end()} \
+| {st.newEmpty()} ";" {st.end()} \
+| {st.newAssign()} Assign ";" {st.end()} \
+| {st.newExpr()} "(" ExpOr ")" ";" {st.end()} \
+| {st.newWhile()} "WHILE" "(" ExpOr ")"{st.whileBody()} Stmt {st.end()}
 Type ::= PrimType {!v_0} | "CLASS_ID" {!} | "ARRAY" PrimType {!Utils.concat(v_0, v_1)}
 VarF ::= "λ" | Chain | "[" ExpOr "]"
 VarsF ::= "λ" {!List.of()} | "," Vars {!v_1}