Extract main function name

3 files changed, 25 insertions, 5 deletions

diff --git a/src/main/java/org/shedlang/compiler/config/ConfigChecker.java b/src/main/java/org/shedlang/compiler/config/ConfigChecker.java
index fe607f83..5ffa074c 100644
--- a/src/main/java/org/shedlang/compiler/config/ConfigChecker.java
+++ b/src/main/java/org/shedlang/compiler/config/ConfigChecker.java
@@ -8,6 +8,8 @@ import org.shedlang.compiler.types.Types;
 
 import java.util.List;
 
+import static org.shedlang.compiler.config.MainFunction.MAIN_FUNCTION_NAME;
+
 public class ConfigChecker {
     private ConfigChecker() {
     }
@@ -20,10 +22,14 @@ public class ConfigChecker {
 
     static void configCheckBin(BinConfig binConfig, TypeInfos typeInfos) {
         var namespaceTypeInfo = typeInfos.namespaceTypeInfo(binConfig.mainNamespace())
-            .orElseThrow(() -> new ConfigError("Namespace " + binConfig.mainNamespace() + " not found"));
+            .orElseThrow(() -> new ConfigError(
+                "Namespace " + binConfig.mainNamespace() + " not found"
+            ));
 
-        var mainType = namespaceTypeInfo.fieldType("main")
-            .orElseThrow(() -> new ConfigError("Namespace " + binConfig.mainNamespace() + " has no field main"));
+        var mainType = namespaceTypeInfo.fieldType(MAIN_FUNCTION_NAME)
+            .orElseThrow(() -> new ConfigError(
+                "Namespace " + binConfig.mainNamespace() + " has no field " + MAIN_FUNCTION_NAME
+            ));
 
         var expectedMainType = new FunctionType(
             List.of(),
@@ -33,7 +39,11 @@ public class ConfigChecker {
         );
 
         if (!mainType.equals(expectedMainType)) {
-            throw new ConfigError("main function should have type " + expectedMainType.describe() + ", but " + binConfig.mainNamespace() + ".main has type " + mainType.describe());
+            throw new ConfigError(
+                MAIN_FUNCTION_NAME + " function should have type " + expectedMainType.describe() +
+                    ", but " + binConfig.mainNamespace() + "." + MAIN_FUNCTION_NAME +
+                    " has type " + mainType.describe()
+            );
         }
     }
 }
diff --git a/src/main/java/org/shedlang/compiler/config/MainFunction.java b/src/main/java/org/shedlang/compiler/config/MainFunction.java
new file mode 100644
index 00000000..0a20d1b3
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/config/MainFunction.java
@@ -0,0 +1,8 @@
+package org.shedlang.compiler.config;
+
+public class MainFunction {
+    private MainFunction() {
+    }
+
+    public static final String MAIN_FUNCTION_NAME = "main";
+}
diff --git a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
index d0a04c97..ccacdf8e 100644
--- a/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
+++ b/src/main/java/org/shedlang/compiler/patio/PatioCodeGen.java
@@ -16,6 +16,8 @@ import org.shedlang.compiler.types.NamespaceName;
 import java.util.*;
 import java.util.function.Function;
 
+import static org.shedlang.compiler.config.MainFunction.MAIN_FUNCTION_NAME;
+
 public class PatioCodeGen {
     private PatioCodeGen() {}
 
@@ -66,7 +68,7 @@ public class PatioCodeGen {
                     mainField,
                     namespaceValue,
                     main,
-                    "main",
+                    MAIN_FUNCTION_NAME,
                     source,
                     mainContext
                 );