Include character location in parse failures

5 files changed, 39 insertions, 26 deletions

diff --git a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/DocumentMatcherParser.java b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/DocumentMatcherParser.java
index 368bc81..418b4be 100644
--- a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/DocumentMatcherParser.java
+++ b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/DocumentMatcherParser.java
@@ -12,8 +12,8 @@ import java.util.function.BiConsumer;
 
 public class DocumentMatcherParser {
     public static BiConsumer<StyleMapBuilder, HtmlPath> parse(TokenIterator tokens) {
-        String identifier = tokens.nextValue(TokenType.IDENTIFIER);
-        switch (identifier) {
+        Token identifier = tokens.next(TokenType.IDENTIFIER);
+        switch (identifier.getValue()) {
             case "p":
                 ParagraphMatcher paragraph = parseParagraphMatcher(tokens);
                 return (builder, path) -> builder.mapParagraph(paragraph, path);
@@ -29,7 +29,7 @@ public class DocumentMatcherParser {
             case "strike":
                 return StyleMapBuilder::strikethrough;
             default:
-                throw new ParseException("Unrecognised document element: " + identifier);
+                throw new ParseException(identifier, "Unrecognised document element: " + identifier);
         }
     }
 
@@ -82,13 +82,14 @@ public class DocumentMatcherParser {
     }
 
     private static boolean parseListType(TokenIterator tokens) {
-        String listType = tokens.nextValue(TokenType.IDENTIFIER);
-        if (listType.equals("ordered-list")) {
-            return true;
-        } else if (listType.equals("unordered-list")) {
-            return false;
-        } else {
-            throw new ParseException("Unrecognised list type: " + listType);
+        Token listType = tokens.next(TokenType.IDENTIFIER);
+        switch (listType.getValue()) {
+            case "ordered-list":
+                return true;
+            case "unordered-list":
+                return false;
+            default:
+                throw new ParseException(listType, "Unrecognised list type: " + listType);
         }
     }
 }
diff --git a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/ParseException.java b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/ParseException.java
index 718bb30..61a7c22 100644
--- a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/ParseException.java
+++ b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/ParseException.java
@@ -1,7 +1,7 @@
 package org.zwobble.mammoth.internal.styles.parsing;
 
 public class ParseException extends RuntimeException {
-    public ParseException(String message) {
-        super(message);
+    public ParseException(Token token, String message) {
+        super("error reading style map at character " + (token.getCharacterIndex() + 1) + ": " + message);
     }
 }
diff --git a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/StyleMappingTokeniser.java b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/StyleMappingTokeniser.java
index 4c6a2a9..9806d67 100644
--- a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/StyleMappingTokeniser.java
+++ b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/StyleMappingTokeniser.java
@@ -14,7 +14,7 @@ public class StyleMappingTokeniser {
             index += token.getValue().length();
         }
 
-        tokens.add(new Token(TokenType.EOF, ""));
+        tokens.add(new Token(index, TokenType.EOF, ""));
         return tokens;
     }
 
@@ -32,7 +32,7 @@ public class StyleMappingTokeniser {
                 index -= 1;
             }
         }
-        return new Token(tokenType, line.substring(startIndex, index));
+        return new Token(startIndex, tokenType, line.substring(startIndex, index));
     }
 
     private static TokenType tokenType(char nextChar) {
diff --git a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/Token.java b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/Token.java
index f6b771e..3059e5b 100644
--- a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/Token.java
+++ b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/Token.java
@@ -1,14 +1,20 @@
 package org.zwobble.mammoth.internal.styles.parsing;
 
 public class Token {
+    private final int characterIndex;
     private final TokenType tokenType;
     private final String value;
 
-    public Token(TokenType tokenType, String value) {
+    public Token(int characterIndex, TokenType tokenType, String value) {
+        this.characterIndex = characterIndex;
         this.tokenType = tokenType;
         this.value = value;
     }
 
+    public int getCharacterIndex() {
+        return characterIndex;
+    }
+
     public TokenType getTokenType() {
         return tokenType;
     }
diff --git a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/TokenIterator.java b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/TokenIterator.java
index f006007..7ee27e9 100644
--- a/src/main/java/org/zwobble/mammoth/internal/styles/parsing/TokenIterator.java
+++ b/src/main/java/org/zwobble/mammoth/internal/styles/parsing/TokenIterator.java
@@ -19,39 +19,45 @@ public class TokenIterator {
         return tokens.get(index + count).getTokenType();
     }
 
-    public String nextValue(TokenType type) {
+    public Token next(TokenType type) {
         Token token = tokens.get(index);
         if (token.getTokenType() == type) {
             index += 1;
-            return token.getValue();
+            return token;
         } else {
-            throw unexpectedTokenType(type, token.getTokenType());
+            throw unexpectedTokenType(type, token);
         }
     }
 
+    public String nextValue(TokenType type) {
+        return next(type).getValue();
+    }
+
     public void skip() {
         index += 1;
     }
 
     public void skip(TokenType tokenType) {
-        if (peekTokenType() != tokenType) {
-            throw unexpectedTokenType(tokenType, peekTokenType());
+        Token token = tokens.get(index);
+        if (token.getTokenType() != tokenType) {
+            throw unexpectedTokenType(tokenType, token);
         }
         index += 1;
     }
 
     public void skip(TokenType tokenType, String tokenValue) {
-        if (peekTokenType() != tokenType) {
-            throw unexpectedTokenType(tokenType, peekTokenType());
+        Token token = tokens.get(index);
+        if (token.getTokenType() != tokenType) {
+            throw unexpectedTokenType(tokenType, token);
         }
-        String actualValue = tokens.get(index).getValue();
+        String actualValue = token.getValue();
         if (!actualValue.equals(tokenValue)) {
-            throw new ParseException("expected " + tokenType + " token with value " + tokenValue + " but value was " + actualValue);
+            throw new ParseException(token, "expected " + tokenType + " token with value " + tokenValue + " but value was " + actualValue);
         }
         index += 1;
     }
 
-    private ParseException unexpectedTokenType(TokenType expected, TokenType actual) {
-        return new ParseException("expected token of type " + expected + " but was of type " + actual);
+    private ParseException unexpectedTokenType(TokenType expected, Token actual) {
+        return new ParseException(actual, "expected token of type " + expected + " but was of type " + actual.getTokenType());
     }
 }