allow uderscore in variable name

build.sbt

@@ -1,10 +1,10 @@
-scalacOptions in ThisBuild ++= Seq("-deprecation", "-feature")
+ThisBuild / scalacOptions ++= Seq("-deprecation", "-feature")
 
 organization := "pl.newicom.scalexpr"
 
 name := "scalexpr"
 
-scalaVersion := "2.13.3"
+scalaVersion := "2.13.6"
 
 publishMavenStyle := true
 homepage := Some(new URL("http://github.com/pawelkaczor/scalexpr"))

project/build.properties

@@ -1 +1 @@
-sbt.version=1.4.5
+sbt.version=1.5.4

src/main/scala/br/com/virsox/scalexpr/ExpressionParser.scala

@@ -70,7 +70,7 @@ class ExpressionParser extends DateParser {
   // ---------------------------------------------------------------
   // -----------------    General parsers     ----------------------
   // ---------------------------------------------------------------
-  def chars[_: P]: P[Unit]  = P(CharIn("a-zA-Z"))
+  def chars[_: P]: P[Unit]  = P(CharIn("a-zA-Z_"))
   def digits[_: P]: P[Unit] = P(CharIn("0-9"))
 
   // ---------------------------------------------------------------

src/test/scala/br/com/virsox/scalexpr/ExpressionParserTest.scala

@@ -100,6 +100,13 @@ class ExpressionParserTest extends AnyFlatSpec with Matchers {
     )
   }
 
+  it should "parse relational expression with a var containing underscore" in new Fixture {
+    verify(
+      parser.parseRelationalExpression("""a_var > 5"""),
+      RelationalExpression(BigDecimalVar("a_var"), GreaterThan, BigDecimalConstant(5))
+    )
+  }
+
   it should "parse comparison expressions with variables on both sides" in new Fixture {
     verify(parser.parseBooleanExpression("""a == b"""), BigDecimalVar("a") == BigDecimalVar("b"))
     verify(parser.parseBooleanExpression("""a != b"""), BigDecimalVar("a") != BigDecimalVar("b"))
@@ -154,6 +161,14 @@ class ExpressionParserTest extends AnyFlatSpec with Matchers {
     )
   }
 
+  it should "parse boolean expressions with parenthesis 2" in new Fixture {
+    verify(
+      parser.parseBooleanExpression("""isFirst == 1 || (name == "Test" && age == 19)"""),
+      (BigDecimalVar("isFirst") == BigDecimalConstant(1)) ||
+        ((StringVar("name") == StringConstant("Test")) && (BigDecimalVar("age") == BigDecimalConstant(19)))
+    )
+  }
+
   it should "parse complex boolean expressions with parenthesis" in new Fixture {
     verify(
       parser.parseBooleanExpression("""(name == "Wilson" && age  > (base + 2.0)) || (name == "Test" && age == ( 4 * 2))"""),

version.sbt

@@ -1 +1 @@
-version in ThisBuild := "0.1.2"
+ThisBuild / version := "0.1.3"