Print Toml element indexes properly

4 files changed, 47 insertions, 13 deletions

diff --git a/src/main/java/org/shedlang/compiler/config/ProjectConfig.java b/src/main/java/org/shedlang/compiler/config/ProjectConfig.java
index 7c2533a1..8f5f63e2 100644
--- a/src/main/java/org/shedlang/compiler/config/ProjectConfig.java
+++ b/src/main/java/org/shedlang/compiler/config/ProjectConfig.java
@@ -1,6 +1,7 @@
 package org.shedlang.compiler.config;
 
 import org.shedlang.compiler.config.errors.TomlSyntaxConfigError;
+import org.shedlang.compiler.config.toml.TomlPath;
 import org.shedlang.compiler.config.toml.TomlTableWithSource;
 import org.shedlang.compiler.sources.Source;
 import org.shedlang.compiler.sources.Sources;
@@ -42,7 +43,7 @@ public record ProjectConfig(
             throw TomlSyntaxConfigError.fromTomljError(error, source);
         }
 
-        return fromToml(projectPath, new TomlTableWithSource(result, P.vector(), source));
+        return fromToml(projectPath, new TomlTableWithSource(result, TomlPath.TOP, source));
     }
 
     public static ProjectConfig fromToml(Path root, TomlTableWithSource table) {
diff --git a/src/main/java/org/shedlang/compiler/config/errors/UnexpectedTypeConfigError.java b/src/main/java/org/shedlang/compiler/config/errors/UnexpectedTypeConfigError.java
index 4c3ba6c5..0b0eda67 100644
--- a/src/main/java/org/shedlang/compiler/config/errors/UnexpectedTypeConfigError.java
+++ b/src/main/java/org/shedlang/compiler/config/errors/UnexpectedTypeConfigError.java
@@ -1,13 +1,13 @@
 package org.shedlang.compiler.config.errors;
 
+import org.shedlang.compiler.config.toml.TomlPath;
 import org.shedlang.compiler.sources.Source;
 
 import java.text.MessageFormat;
-import java.util.List;
 
 public class UnexpectedTypeConfigError extends ConfigError {
     public UnexpectedTypeConfigError(
-        List<String> path,
+        TomlPath path,
         String expectedType,
         Class<?> actualType,
         Source source
@@ -15,7 +15,7 @@ public class UnexpectedTypeConfigError extends ConfigError {
         super(
             MessageFormat.format(
                 "Expected {0} to be {1}, but was {2}",
-                String.join(".", path),
+                path,
                 expectedType,
                 actualType.getSimpleName()
             ),
diff --git a/src/main/java/org/shedlang/compiler/config/toml/TomlPath.java b/src/main/java/org/shedlang/compiler/config/toml/TomlPath.java
new file mode 100644
index 00000000..dc5910a9
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/config/toml/TomlPath.java
@@ -0,0 +1,35 @@
+package org.shedlang.compiler.config.toml;
+
+import org.pcollections.PVector;
+import org.shedlang.compiler.util.CheckReturnValue;
+import org.shedlang.compiler.util.P;
+
+import java.text.MessageFormat;
+
+public class TomlPath {
+    public static final TomlPath TOP = new TomlPath(P.vector());
+
+    private final PVector<String> components;
+
+    private TomlPath(PVector<String> components) {
+        this.components = components;
+    }
+
+    @CheckReturnValue
+    public TomlPath plusKey(String key) {
+        // TODO: handle string escaping
+        var component = components.isEmpty() ? key : "." + key;
+        return new TomlPath(this.components.plus(component));
+    }
+
+    @CheckReturnValue
+    public TomlPath plusIndex(int index) {
+        var component = MessageFormat.format("[{0}]", index);
+        return new TomlPath(this.components.plus(component));
+    }
+
+    @Override
+    public String toString() {
+        return String.join("", this.components);
+    }
+}
diff --git a/src/main/java/org/shedlang/compiler/config/toml/TomlTableWithSource.java b/src/main/java/org/shedlang/compiler/config/toml/TomlTableWithSource.java
index 4f32e761..5b573628 100644
--- a/src/main/java/org/shedlang/compiler/config/toml/TomlTableWithSource.java
+++ b/src/main/java/org/shedlang/compiler/config/toml/TomlTableWithSource.java
@@ -1,6 +1,5 @@
 package org.shedlang.compiler.config.toml;
 
-import org.pcollections.PVector;
 import org.shedlang.compiler.config.errors.UnexpectedTypeConfigError;
 import org.shedlang.compiler.sources.Source;
 import org.tomlj.TomlArray;
@@ -13,18 +12,18 @@ import java.util.stream.IntStream;
 
 public record TomlTableWithSource(
     TomlTable table,
-    PVector<String> path,
+    TomlPath path,
     Source fullSource
 ) {
     public Optional<TomlTableWithSource> getTable(String key) {
         var value = table.get(key);
         var position = table.inputPositionOf(key);
 
-        return tomlValueToTable(List.of(key), value, position);
+        return tomlValueToTable(path.plusKey(key), value, position);
     }
 
     private Optional<TomlTableWithSource> tomlValueToTable(
-        List<String> subPath,
+        TomlPath valuePath,
         Object value,
         TomlPosition position
     ) {
@@ -35,13 +34,13 @@ public record TomlTableWithSource(
         if (value instanceof TomlTable valueTable) {
             return Optional.of(new TomlTableWithSource(
                 valueTable,
-                path.plusAll(subPath),
+                valuePath,
                 fullSource
             ));
         }
 
         throw new UnexpectedTypeConfigError(
-            path.plusAll(subPath),
+            valuePath,
             "a table",
             value.getClass(),
             TomlSource.sourceAtTomlPosition(fullSource, position)
@@ -61,7 +60,7 @@ public record TomlTableWithSource(
         }
 
         throw new UnexpectedTypeConfigError(
-            path.plus(key),
+            path.plusKey(key),
             "an array",
             value.getClass(),
             TomlSource.sourceAtTomlPosition(fullSource, position)
@@ -75,8 +74,7 @@ public record TomlTableWithSource(
                     var element = array.get(index);
                     var elementPosition = array.inputPositionOf(index);
                     return tomlValueToTable(
-                        // TODO: handle indexes in path properly
-                        List.of(key, Integer.toString(index)),
+                        path.plusKey(key).plusIndex(index),
                         element,
                         elementPosition
                     );