misc: more refactorings

Author: ice1000

Diff for: base/src/main/java/org/aya/tyck/unify/TermComparator.java

@@ -256,7 +256,6 @@ private boolean visitLists(SeqView<Term> l, SeqView<Term> r, Sub lr, Sub rl, @No
     else return null;
   }
 
-  @SuppressWarnings("unused")
   private boolean doCompareTyped(@NotNull Term type, @NotNull Term lhs, @NotNull Term rhs, Sub lr, Sub rl) {
     // Skip tracing, because too easy.
     // Note that it looks tempting to apply some unification here, but it is not correct:

Diff for: cli-impl/src/main/java/org/aya/cli/literate/SyntaxHighlight.java

@@ -152,7 +152,6 @@ else if (SPECIAL_SYMBOL.contains(tokenType))
     return kindOf(var).toRef(sourcePos, BasePrettier.linkIdOf(currentFileModule, var), type);
   }
 
-  @SuppressWarnings("unused")
   public static @NotNull DefKind kindOf(@NotNull AnyVar var) {
     return switch (var) {
       case GeneralizedVar _ -> DefKind.Generalized;

Diff for: tools-kala/src/main/java/org/aya/util/terck/Relation.java

@@ -34,7 +34,7 @@ record Decrease(boolean usable, int size) implements Relation {
   @Override default @NotNull Doc toDoc() {
     return switch (this) {
       case Decrease d when d.size == 0 -> Doc.plain("  =");
-      case Decrease d -> Doc.plain((d.usable ? " " : "!") + "-" + d.size);
+      case Decrease d -> Doc.plain(STR."\{d.usable ? " " : "!"}-\{d.size}");
       case Unknown ignored -> Doc.plain("  ?");
     };
   }

Diff for: tools/src/main/java/org/aya/util/error/SourcePos.java

@@ -17,7 +17,6 @@
  * @param tokenStartIndex The index of first character (inclusive)
  * @author kiva
  */
-@SuppressWarnings("unused")
 public record SourcePos(
   @NotNull SourceFile file,
   int tokenStartIndex,
@@ -136,8 +135,7 @@ public int linesOfCode() {
   }
 
   @Override public String toString() {
-    return "(" + tokenStartIndex + "-" + tokenEndIndex + ") ["
-      + startLine + "," + startColumn + "-" + endLine + "," + endColumn + ']';
+    return STR."(\{tokenStartIndex}-\{tokenEndIndex}) [\{startLine},\{startColumn}-\{endLine},\{endColumn}\{']'}";
   }
 
   @Override