rpgsheet

commit 7e6900cc5e0e65f24f0066caa9d1bd9474224a05
parent 0e093c28e583abc029d9903501d72351fe0ae177
Author: Skylar Hill <stellarskylark@posteo.net>
Date:   Sun,  5 Jun 2022 07:11:48 -0500

Error handling for calculating nonexistent expressions

Diffstat:
M
src/verb.nim
 | 
15
++++++++++++++-

1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/src/verb.nim b/src/verb.nim
@@ -18,12 +18,14 @@ type
     View
     Tui
 
+
 proc expressionAsString(node: YamlNode): string =
   result = fmt"""Dice: {node.getContent("dice")}""" & "\n"
   result = result & fmt"""Modifier: {node.getContent("modifier")}""" & "\n"
   result = result & fmt"""Tab: {node.getContent("tab")}""" & "\n"
   result = result & fmt"""Window: {node.getContent("window")}"""
 
+
 proc calculateModifier(exp: string, sheet: YamlDocument): string =
   if exp == "":
     return "0"
@@ -44,9 +46,12 @@ proc calculateModifier(exp: string, sheet: YamlDocument): string =
     return working
 
   for match in exp.findAll reRawExp:
+    if match == exp:
+      raise newException(KeyError, "The expression " & exp & " is not defined.")
     working = working.replace(match, calculateModifier(match, sheet))
   return calculateModifier(working, sheet)
 
+
 proc roll(action: string, sheet: YamlDocument): string =
   if action.contains(reDice):
     let (output, code) = execCmdEx("rolldice -s", input = action)
@@ -60,7 +65,12 @@ proc roll(action: string, sheet: YamlDocument): string =
   except KeyError:
     return action & " is not a dice expression or defined expression"
 
-  var modifier = calculateModifier(exp.getContent("modifier"), sheet)
+  var modifier: string
+  try:
+    modifier = calculateModifier(exp.getContent("modifier"), sheet)
+  except KeyError:
+    return "ERROR: " & getCurrentExceptionMsg()
+
   if not exp.contains "dice":
     return modifier
   let dice = exp.getContent("dice")
@@ -79,16 +89,19 @@ proc roll(action: string, sheet: YamlDocument): string =
     # rolldice returns its input; the actual roll is the second line
     result = output.splitLines[1]
 
+
 proc view(action: string, sheet: YamlDocument): string =
   let node = sheet.getExpression(action)
   echo action & ":"
   echo expressionAsString(node)
 
+
 proc write*(doc: YamlDocument, file: string) =
   let s = newfileStream(file, fmWrite)
   dumpDom(doc, s, options = defineOptions(style = psBlockOnly))
   s.close()
 
+
 proc doVerb*(action: string, verb: Verb, sheet: YamlDocument): string =
   case verb
   of Roll: