Refocus manual on public language usage

doc/manual/souce/index.md

@@ -1,20 +1,20 @@
 # Decodal Manual
 
-このディレクトリには、Decodal のマニュアル文書を置く。
+このマニュアルでは、Decodal の言語仕様と、アプリケーションへ組み込むための公開 API を説明する。
 Decodal は Deferred Constraint Data Language、略称 DCDL のプロジェクト名である。
 
 ## 目次
 
 1. [Introduction](./introduction.md)
-2. [Components](./components.md)
-3. [Language Specification](./language/index.md)
+2. [Language Specification](./language/index.md)
    1. [Lexical Structure and Syntax](./language/syntax.md)
-   2. [Value](./language/value/index.md)
+   2. [Grammar](./language/grammar.md)
+   3. [Value](./language/value/index.md)
       1. [String](./language/value/string.md)
       2. [Int](./language/value/int.md)
       3. [Float](./language/value/float.md)
       4. [Bool](./language/value/bool.md)
-   3. [Expression](./language/expression/index.md)
+   4. [Expression](./language/expression/index.md)
       1. [Literal](./language/expression/literal.md)
       2. [Identifier](./language/expression/identifier.md)
       3. [Path Reference](./language/expression/path-reference.md)
@@ -28,22 +28,15 @@ Decodal は Deferred Constraint Data Language、略称 DCDL のプロジェク
       11. [Composition](./language/expression/composition.md)
       12. [Range Refinement](./language/expression/ascription.md)
       13. [Default](./language/expression/default.md)
-      14. [String Interpolation](./language/expression/string-interpolation.md)
-   4. [Constraints and Defaults](./language/constraints-and-defaults.md)
-   5. [Composition Operators](./language/operators.md)
-   6. [Functions](./language/functions.md)
-   7. [Modules and Imports](./language/modules-and-imports.md)
-   8. [Evaluation Semantics](./language/evaluation.md)
-   9. [Materialization and Errors](./language/materialization-and-errors.md)
-   10. [Naming Conventions](./language/naming.md)
-   11. [Examples](./language/examples.md)
-4. [Implementation Design](./design/index.md)
-   1. [Execution Pipeline](./design/execution-pipeline.md)
-   2. [Runtime Model](./design/runtime-model.md)
-   3. [Thunk and Lazy Evaluation](./design/thunk-and-lazy-evaluation.md)
-   4. [Composition and Materialization](./design/composition-and-materialization.md)
-   5. [Diagnostics and Fallback](./design/diagnostics-and-fallback.md)
-   6. [Embedding API](./design/embedding-api.md)
-   7. [Features](./design/features.md)
-5. [Development](./development.md)
-6. [Open Issues](./open-issues.md)
+      14. [Arithmetic](./language/expression/arithmetic.md)
+      15. [Logical and Comparison](./language/expression/logical-and-comparison.md)
+   5. [Constraints and Defaults](./language/constraints-and-defaults.md)
+   6. [Operators](./language/operators.md)
+   7. [Functions](./language/functions.md)
+   8. [Modules and Imports](./language/modules-and-imports.md)
+   9. [Evaluation Semantics](./language/evaluation.md)
+   10. [Materialization and Errors](./language/materialization-and-errors.md)
+   11. [Naming](./language/naming.md)
+   12. [Examples](./language/examples.md)
+3. [Embedding](./embedding.md)
+4. [Packages and Integrations](./components.md)