Merge pull request #10 from navtech-io/develop

Develop

Author: rajeshjn

src/Simpleflow/CodeGenerator/SimpleflowErrorListener.cs

@@ -16,10 +16,15 @@ internal class SimpleflowErrorListener : BaseErrorListener
         public override void SyntaxError(TextWriter output, IRecognizer recognizer, IToken offendingSymbol, int line, int charPositionInLine,
             string msg, RecognitionException e)
         {
-            Errors.Add(new SyntaxError(recognizer, offendingSymbol, line, charPositionInLine, msg, e));
 
-
-            //base.SyntaxError(output, recognizer, offendingSymbol, line, charPositionInLine, msg, e);
+            if (recognizer.Atn.states[e.OffendingState].StateType == Antlr4.Runtime.Atn.StateType.BlockStart)
+            {
+                Errors.Add(new SyntaxError(recognizer, offendingSymbol, line, charPositionInLine, $"Unexpected token {offendingSymbol.Text}, a newline expected", e));
+            }
+            else
+            {
+                Errors.Add(new SyntaxError(recognizer, offendingSymbol, line, charPositionInLine, msg, e));
+            }
         }
 
         public string GetAggregateMessages()

src/Simpleflow/Parser/Base/SimpleflowParserBase.cs

@@ -3,6 +3,7 @@
 
 using System.IO;
 using Antlr4.Runtime;
+using static Simpleflow.Parser.SimpleflowParser;
 
 namespace Simpleflow.Parser
 {
@@ -21,5 +22,41 @@ protected SimpleflowParserBase(ITokenStream input) : base(input)
         protected SimpleflowParserBase(ITokenStream input, TextWriter output, TextWriter errorOutput) : base(input, output, errorOutput)
         {
         }
+
+
+        protected bool lineTerminatorAhead()
+        {
+            // Get the token ahead of the current index.
+            int possibleIndexEosToken = CurrentToken.TokenIndex -1 ;
+            IToken ahead = ((ITokenStream)this.InputStream).Get(possibleIndexEosToken);
+
+            if (ahead.Channel != Lexer.Hidden)
+            {
+                // We're only interested in tokens on the Hidden channel.
+                return false;
+            }
+
+            if (ahead.Type == LineTerminator)
+            {
+                // There is definitely a line terminator ahead.
+                return true;
+            }
+
+            if (ahead.Type == WhiteSpaces)
+            {
+                // Get the token ahead of the current whitespaces.
+                possibleIndexEosToken = CurrentToken.TokenIndex - 2;
+                ahead = ((ITokenStream)this.InputStream).Get(possibleIndexEosToken);
+            }
+
+            // Get the token's text and type.
+            string text = ahead.Text;
+            int type = ahead.Type;
+
+            // Check if the token is, or contains a line terminator.
+            return (type == MultiLineComment && (text.Contains("\r") || text.Contains("\n"))) ||
+                    (type == LineTerminator);
+        }
+
     }
 }

src/Simpleflow/Parser/Grammar/Simpleflow.g4

@@ -6,14 +6,11 @@ options {
 }
 
 program
-    :
-     LineBreak*
-     letStmt* 
+    : letStmt* 
      (ruleStmt | generalStatement)* EOF; 
 
-
 ruleStmt
-    : Rule When predicate Then LineBreak 
+    : Rule When predicate Then eos 
           (  messageStmt  
            | errorStmt       
            | outputStmt  
@@ -25,11 +22,11 @@ ruleStmt
     ; 
 
 endRuleStmt
-    : 'end' 'rule' LineBreak
+    : 'end' 'rule' eos
     ;
 
 exitStmt
-    : 'exit' LineBreak
+    : 'exit' eos
     ;
 
 generalStatement
@@ -42,37 +39,42 @@ generalStatement
     ;
 
 letStmt
-    : Let Identifier Assign expression LineBreak  
+    : Let Identifier Assign expression eos  
     ;
 
 setStmt
-    : (Partial)? Set Identifier Assign expression LineBreak  
+    : (Partial)? Set Identifier Assign expression eos  
     ;
 
 messageStmt
-    : Message messageText LineBreak
+    : Message messageText eos
     ;
 
 errorStmt
-    : Error messageText LineBreak
+    : Error messageText eos
     ;
 
 messageText
     : (String | objectIdentifier)
     ;
 
 outputStmt
-    : Output objectIdentifier LineBreak
+    : Output objectIdentifier eos
     ;
 
 functionStmt
-    : function LineBreak
+    : function eos
     ;    
 
 expression
     : boolLeteral | noneLiteral | function | jsonObj | arithmeticExpression | stringLiteral
     ;
 
+eos
+    : EOF
+    | {this.lineTerminatorAhead()}?
+    ;
+
 // Lexer
 
 Rule
@@ -101,15 +103,12 @@ Partial
 Assign
    : '=' ;
 
-LineBreak
-    : [\r\n]+[ \t\r\n]*
-    ;
+WhiteSpaces:              
+    [\t\u000B\u000C\u0020\u00A0]+ -> channel(HIDDEN);
 
-Skip_
-    : ( SPACES | COMMENT ) -> skip    ;
+LineTerminator:
+    [\r\n\u2028\u2029] -> channel(HIDDEN);
 
-fragment SPACES
-    : [ \t]+  ;
+MultiLineComment:   
+   '/*' .*? '*/'  -> channel(HIDDEN);
 
-fragment COMMENT
-    : '/*' .*? '*/' ([\r\n]*) ;

src/Simpleflow/Parser/Simpleflow.interp

@@ -17,30 +17,31 @@ Let=16
 Set=17
 Partial=18
 Assign=19
-LineBreak=20
-Skip_=21
-And=22
-Or=23
-Not=24
-GreaterThan=25
-GreaterThanEqual=26
-LessThan=27
-LessThanEqual=28
-Equal=29
-NotEqual=30
-Contains=31
-OpenParen=32
-CloseParen=33
-Number=34
-String=35
-None=36
-Identifier=37
-PlusOp=38
-MinusOp=39
-TimesOp=40
-DivOp=41
-ModuloOp=42
-FunctionName=43
+WhiteSpaces=20
+LineTerminator=21
+MultiLineComment=22
+And=23
+Or=24
+Not=25
+GreaterThan=26
+GreaterThanEqual=27
+LessThan=28
+LessThanEqual=29
+Equal=30
+NotEqual=31
+Contains=32
+OpenParen=33
+CloseParen=34
+Number=35
+String=36
+None=37
+Identifier=38
+PlusOp=39
+MinusOp=40
+TimesOp=41
+DivOp=42
+ModuloOp=43
+FunctionName=44
 'end'=1
 'exit'=2
 '.'=3
@@ -60,21 +61,21 @@ FunctionName=43
 'set'=17
 'partial'=18
 '='=19
-'and'=22
-'or'=23
-'not'=24
-'>'=25
-'>='=26
-'<'=27
-'<='=28
-'=='=29
-'!='=30
-'contains'=31
-'('=32
-')'=33
-'none'=36
-'+'=38
-'-'=39
-'*'=40
-'/'=41
-'%'=42
+'and'=23
+'or'=24
+'not'=25
+'>'=26
+'>='=27
+'<'=28
+'<='=29
+'=='=30
+'!='=31
+'contains'=32
+'('=33
+')'=34
+'none'=37
+'+'=39
+'-'=40
+'*'=41
+'/'=42
+'%'=43

src/Simpleflow/Parser/Simpleflow.tokens

@@ -193,6 +193,18 @@ public virtual void EnterExpression([NotNull] SimpleflowParser.ExpressionContext
 	/// <param name="context">The parse tree.</param>
 	public virtual void ExitExpression([NotNull] SimpleflowParser.ExpressionContext context) { }
 	/// <summary>
+	/// Enter a parse tree produced by <see cref="SimpleflowParser.eos"/>.
+	/// <para>The default implementation does nothing.</para>
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	public virtual void EnterEos([NotNull] SimpleflowParser.EosContext context) { }
+	/// <summary>
+	/// Exit a parse tree produced by <see cref="SimpleflowParser.eos"/>.
+	/// <para>The default implementation does nothing.</para>
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	public virtual void ExitEos([NotNull] SimpleflowParser.EosContext context) { }
+	/// <summary>
 	/// Enter a parse tree produced by <see cref="SimpleflowParser.predicate"/>.
 	/// <para>The default implementation does nothing.</para>
 	/// </summary>

src/Simpleflow/Parser/SimpleflowBaseListener.cs

@@ -166,6 +166,16 @@ internal partial class SimpleflowBaseVisitor<Result> : AbstractParseTreeVisitor<
 	/// <return>The visitor result.</return>
 	public virtual Result VisitExpression([NotNull] SimpleflowParser.ExpressionContext context) { return VisitChildren(context); }
 	/// <summary>
+	/// Visit a parse tree produced by <see cref="SimpleflowParser.eos"/>.
+	/// <para>
+	/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
+	/// on <paramref name="context"/>.
+	/// </para>
+	/// </summary>
+	/// <param name="context">The parse tree.</param>
+	/// <return>The visitor result.</return>
+	public virtual Result VisitEos([NotNull] SimpleflowParser.EosContext context) { return VisitChildren(context); }
+	/// <summary>
 	/// Visit a parse tree produced by <see cref="SimpleflowParser.predicate"/>.
 	/// <para>
 	/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>