[template-glib] expr: allow escaping newlines

[Christian Hergert <chergert src gnome org>]

commit 5c7e99c04f4803ba46a7893a329896d73cd01f58
Author: Christian Hergert <chergert redhat com>
Date:   Fri May 6 10:25:40 2022 -0700

    expr: allow escaping newlines

 src/tmpl-expr-scanner.l | 1 +
 tests/test1.script      | 5 +++++
 2 files changed, 6 insertions(+)
---
diff --git a/src/tmpl-expr-scanner.l b/src/tmpl-expr-scanner.l
index 8abcfcb..3ed530a 100644
--- a/src/tmpl-expr-scanner.l
+++ b/src/tmpl-expr-scanner.l
@@ -127,6 +127,7 @@ L?\"(\\.|[^\\"])*\" { yylval->s = copy_literal (yytext); return STRING_LITERAL;
 
 "//".*
 [ \t]   /* ignore whitespace */
+"\\\n"  /* ignore escpaed newlines */
 #[^\n]* { return EOL; } /* line-wise comments should EOL things */
 "\n"    { return EOL; }
 <<EOF>> { parser->reached_eof = TRUE; return EOL; }
diff --git a/tests/test1.script b/tests/test1.script
index 733b464..802fdf5 100644
--- a/tests/test1.script
+++ b/tests/test1.script
@@ -89,4 +89,9 @@ end
 mycount = 2
 assert(count() == 3)
 
+multiline = (1 + \
+             2 + \
+             3)
+assert(multiline == 6)
+
 1234;