feat: unify expr print

Author: swananan

docs/scripting.md

@@ -88,7 +88,19 @@ let message = "hello";
 let result = a + b;
 ```
 
-Script variables currently support integers, floats, and strings.
+Script variable types and capabilities:
+
+| Type | Literal/Example | Description | Ops/Comparisons |
+| --- | --- | --- | --- |
+| Integer (int, internally i64) | `123`, `-42` | Signed 64-bit integer | +, -, *, /; can mix with DWARF integer-like scalars |
+| Boolean (bool) | from comparisons: `a < b` | Produced by comparisons/logical expressions | logical AND/OR (script only); when mixing with DWARF integers, treated as 0/1 |
+| String | `"hello"` | UTF-8 string literal | Equality `==`, `!=` with DWARF C strings; no ordering comparisons |
+
+Notes:
+1. Script variables do not support user-defined structs/arrays/pointers; access such data via DWARF variables (member access, deref, constant index) to obtain scalars first.
+2. Floating-point arithmetic is not supported.
+3. Unary minus `-` is supported and can be nested (e.g., `-1`, `-(-1)`), parsed as `0 - expr`.
+4. Transport encodes booleans as a single byte 0/1; the renderer displays `true`/`false`.
 
 ### Local Variables, Parameters, and Global Variables
 
@@ -205,7 +217,7 @@ let quotient = a / b;  // Division
 
 1. Parentheses `()`
 2. Member access `.`, Array access `[]`
-3. Pointer dereference `*`, Address of `&`
+3. Pointer dereference `*`, Address of `&`, Unary minus `-`
 4. Multiplication `/`, Division `/`
 5. Addition `+`, Subtraction `-`
 6. Comparisons `==`, `!=`, `<`, `<=`, `>`, `>=`
@@ -226,6 +238,11 @@ let complex = (x + y) / (a - b);
 - Operands are treated as booleans with "non-zero is true" semantics
 - Current implementation evaluates both sides (no short-circuit yet)
 
+Boolean values
+
+- Comparisons and logical operators produce boolean results.
+- Transport encodes booleans as a single byte 0/1. The renderer displays them as `true`/`false`.
+
 Examples
 
 ```ghostscope
@@ -238,6 +255,20 @@ trace main:entry {
 }
 ```
 
+### Unary Minus
+
+- Semantics: negate an expression; recursive nesting is supported.
+- Parsing: treated as `0 - expr`, ensuring `-1`, `-x`, and `-(-1)` evaluate as signed integers.
+
+```ghostscope
+trace foo.c:42 {
+    let a = -1;          // a = -1
+    let b = -(-1);       // b = 1
+    print a;             // Output: a = -1
+    print "X:{}", b;     // Output: X:1
+}
+```
+
 ### Cross-type Operations With DWARF Values
 
 - Arithmetic (+, -, *, /)

docs/zh/scripting.md

@@ -98,6 +98,8 @@ let result = a + b;
 说明：
 1. 目前脚本层不支持自定义结构体/数组/指针类型；对于这些聚合类型，请通过 DWARF 变量访问（成员访问、解引用、常量下标）来获取标量后再参与运算。
 2. eBPF 不支持浮点运算，故当前脚本变量不支持浮点字面量与浮点运算
+3. 一元负号（`-`）已支持并可嵌套：例如 `-1`、`-(-1)` 均合法；解析等价于 `0 - x` 的语义。
+4. 布尔传输层使用 0/1 表示，展示层统一渲染为 `true/false`。
 
 ### DWARF 变量
 
@@ -267,7 +269,7 @@ let quotient = a / b;  // 除法
 
 1. 括号 `()`
 2. 成员访问 `.`，数组访问 `[]`
-3. 指针解引用 `*`，取地址 `&`
+3. 指针解引用 `*`，取地址 `&`，一元负号 `-`
 4. 乘法 `*`，除法 `/`
 5. 加法 `+`，减法 `-`
 6. 比较 `==`, `!=`, `<`, `<=`, `>`, `>=`
@@ -342,11 +344,7 @@ trace foo.c:60 {
     print "greet-ok:{}", gm == "Hello, Global!"; // gm: const char* 或 char[]
 }
 
-// 纯脚本浮点（编译期折叠）。与 DWARF 混用暂不支持。
-trace foo.c:70 {
-    let x = 1.5 * 2.0; // 编译期折叠
-    if x > 2.0 { print "ok"; }
-}
+
 ```
 
 ## 栈回溯语句（实现中）
@@ -466,3 +464,17 @@ trace server_respond {
 - 字符串字面量必须使用双引号
 - 大多数语句需要分号
 - 追踪模式匹配支持文件模糊匹配（参见[命令参考](command-reference.md)）
+### 一元负号（Unary Minus）
+
+- 语义：对表达式取相反数，支持递归嵌套。
+- 解析：按 `0 - expr` 处理，确保 `-1`、`-x`、`-(-1)` 等都按有符号整数求值。
+- 示例：
+
+```ghostscope
+trace foo.c:42 {
+    let a = -1;          // a = -1
+    let b = -(-1);       // b = 1
+    print a;             // 输出: a = -1
+    print "X:{}", b;     // 输出: X:1
+}
+```