Add logical and comparison expressions

2026-06-17 23:38:44 +09:00
parent 3f7dd7c692
commit 2fe54bda62
18 changed files with 6627 additions and 4620 deletions
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+# Logical and Comparison Expressions
+
+Decodal supports boolean logic over concrete `Bool` values and comparison over concrete scalar values.
+
+```dcdl
+{
+    is_prod = env == "prod";
+    high_port = port > 9000;
+    enabled = is_prod && high_port;
+    disabled = !enabled;
+}
+```
+
+## Logical operators
+
+- `!expr` negates a concrete `Bool`.
+- `lhs && rhs` returns boolean AND.
+- `lhs || rhs` returns boolean OR.
+
+`&&` and `||` short-circuit: the right-hand side is evaluated only when needed.
+Logical operands must evaluate to concrete `Bool` values.
+
+## Comparison operators
+
+- `==`
+- `!=`
+- `<`
+- `<=`
+- `>`
+- `>=`
+
+`==` and `!=` compare concrete scalar values: `String`, `Bool`, `Int`, and `Float`.
+`Int` and `Float` can be compared to each other numerically.
+
+Ordering operators `<`, `<=`, `>`, and `>=` compare concrete numeric values only.
+They are separate from prefix comparison constraints such as `> 443`.
+
+```dcdl
+port = Int & > 443 default 9443;
+is_high = port > 9000;
+```