ignores consecutive escaped characters

sychoo · Jul 3, 2019 · 503925f · 503925f
1 parent d727c6c
commit 503925f
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Showing 2 changed files with 30 additions and 10 deletions.
diff --git a/examples/tsls/formatstring.wyv b/examples/tsls/formatstring.wyv
@@ -99,9 +99,7 @@ def parseExpr(input : String, ctx : system.Context) : ParsedExpr
             makeParsedExpr(option.None[AST](), input)
 
 
-//val prefixRegex : regex.Regex = regex("(\\\\|\\%|[^%])+")
-//alternative approach: if last char of prefixString is \ and next matches %, replace it with % and append to parseTSL
-//would need to replace \ in string even if using regex
+//val prefixRegex : regex.Regex = regex("(\\\\\\\\|\\\\%|[^%])+")
 val prefixRegex : regex.Regex = regex("[^\\\\%]+")
 //val prefixRegex : regex.Regex = regex("[^%]+")
 
@@ -174,10 +172,34 @@ def parse(input : String, ctx : system.Context) : option.Option[AST]
                   else
                     option.None[AST]() //recursive call gives None
               else
-                option.None[AST]() //cannot parse expression
+                // can only reach here if first character starts with \
+                if (input.charAt(0) == #"\\")
+                    if (input.length() >= 2)
+                        if (input.charAt(1) == #"%")
+                            val recursiveCall : option.Option[AST] = parse(input.substring(2,input.length()), ctx)
+                            if (recursiveCall.isDefined)
+                                option.Some[AST](ast.call(ast.string("%"), "+", {recursiveCall.get()}))
+                              else
+                                option.None[AST]()
+                          else
+                            if (input.charAt(1) == #"\\")
+                                val recursiveCall : option.Option[AST] = parse(input.substring(2,input.length()), ctx)
+                                if (recursiveCall.isDefined)
+                                    option.Some[AST](ast.call(ast.string("\\"), "+", {recursiveCall.get()}))
+                                  else
+                                    option.None[AST]()
+                              else
+                                val recursiveCall : option.Option[AST] = parse(input.substring(1,input.length()), ctx)
+                                if (recursiveCall.isDefined)
+                                    option.Some[AST](ast.call(ast.string("\\"), "+", {recursiveCall.get()}))
+                                  else
+                                    option.None[AST]()
+                      else
+                        option.Some[AST](ast.string(input))
+                  else
+                    option.None[AST]() //cannot parse expression
+
 
-//include \% + other characters, except pure %
-//TODO: ignore escape character (\%)
 type FormatString = String
     metadata new
         def parseTSL(input : String, ctx : system.Context) : option.Option[AST]

diff --git a/examples/tsls/formatstringClient.wyv b/examples/tsls/formatstringClient.wyv
@@ -9,13 +9,11 @@ def printf(str:formatstring.FormatString):Unit
 
 //just a plain string
 printf(~)
- Hello \\ \%World!
-
-/*
+ Hello \\\%World!\n
+
 printf(~)
  Hello %{"string!"}%{" \"}{mm}"} and %{ "another string!" }
 
 val x = 3
 printf(~)
  %{x} %{4} %.5{1.6} %{1.7}
-*/