diff --git a/CORDIAL_GUIDE.md b/CORDIAL_GUIDE.md
new file mode 100644
index 0000000..76664ff
--- /dev/null
+++ b/CORDIAL_GUIDE.md
@@ -0,0 +1,781 @@
+# Cordial Language Reference Guide
+
+Cordial is a simple, expression-based programming language embedded in Swiftly. This guide documents every working feature.
+
+## Evaluation Prefix
+
+All evaluation in the editor uses the `/=` prefix:
+
+```
+/= 2 + 3
+```
+
+Output:
+```
+5
+```
+
+## Types
+
+Cordial has five value types:
+
+- **number**: floating-point numbers (internally f64). Displayed as integers when they have no fractional part.
+- **bool**: `true` or `false`
+- **str**: strings in double quotes, with escape sequences (`\n`, `\t`, `\\`, `\"`)
+- **array**: ordered collections of values
+- **void**: the value returned by statements with no explicit value
+
+## Variables
+
+### Declaration
+
+Use `let` to declare and initialize a variable:
+
+```
+let x = 5
+/= x
+```
+
+Output:
+```
+5
+```
+
+### Type Annotations
+
+Optionally annotate the type after the variable name:
+
+```
+let x: int = 3.7
+/= x
+```
+
+Output:
+```
+3
+```
+
+Supported type annotations:
+- `int`: truncates numbers to integers
+- `float`: accepts any number (no coercion)
+- `bool`: converts 0 to `false`, 1 to `true`; rejects other numbers
+- `str`: only accepts strings
+
+```
+let b: bool = 1
+/= b
+```
+
+Output:
+```
+true
+```
+
+### Assignment
+
+Reassign an existing variable without `let`:
+
+```
+let x = 5
+x = 10
+/= x
+```
+
+Output:
+```
+10
+```
+
+## Operators
+
+### Arithmetic
+
+- `+`: addition or string concatenation
+- `-`: subtraction
+- `*`: multiplication
+- `/`: division (errors on division by zero)
+- `%`: modulo
+- `^`: exponentiation (right-associative)
+
+```
+/= 2 ^ 3 ^ 2
+```
+
+Output:
+```
+512
+```
+
+(Evaluated as 2 ^ (3 ^ 2) = 2 ^ 9 = 512)
+
+### Comparison
+
+All comparison operators return booleans:
+
+- `<`: less than
+- `>`: greater than
+- `<=`: less than or equal
+- `>=`: greater than or equal
+- `==`: equality
+- `!=`: inequality
+
+```
+/= 5 > 3
+```
+
+Output:
+```
+true
+```
+
+### Logical
+
+- `&&`: logical AND (short-circuits)
+- `||`: logical OR (short-circuits)
+- `!`: logical NOT
+
+```
+/= true && false
+```
+
+Output:
+```
+false
+```
+
+```
+/= !true
+```
+
+Output:
+```
+false
+```
+
+### Operator Precedence
+
+From lowest to highest:
+1. `||`
+2. `&&`
+3. `==`, `!=`, `<`, `>`, `<=`, `>=`
+4. `+`, `-`
+5. `*`, `/`, `%`
+6. `^` (right-associative)
+7. unary `-`, `!`
+8. function calls, array literals
+
+## Strings
+
+String literals use double quotes:
+
+```
+/= "hello"
+```
+
+Output:
+```
+hello
+```
+
+Escape sequences:
+- `\n`: newline
+- `\t`: tab
+- `\\`: backslash
+- `\"`: double quote
+
+### String Concatenation
+
+Strings concatenate with the `+` operator. Numbers and booleans are automatically converted:
+
+```
+/= "value: " + 42
+```
+
+Output:
+```
+value: 42
+```
+
+```
+/= 100 + " items"
+```
+
+Output:
+```
+100 items
+```
+
+## Arrays
+
+### Literals
+
+Create arrays with square brackets:
+
+```
+/= [1, 2, 3]
+```
+
+Output:
+```
+[1, 2, 3]
+```
+
+Arrays can contain mixed types:
+
+```
+/= [1, "two", true]
+```
+
+Output:
+```
+[1, "two", true]
+```
+
+Empty arrays:
+
+```
+/= []
+```
+
+Output:
+```
+[]
+```
+
+### Indexing
+
+Access elements by index (zero-based):
+
+```
+let arr = [10, 20, 30]
+/= arr[1]
+```
+
+Output:
+```
+20
+```
+
+Negative indices count from the end:
+
+```
+/= [10, 20, 30][-1]
+```
+
+Output:
+```
+30
+```
+
+Out-of-bounds access returns an error.
+
+### String Indexing
+
+Strings support the same index syntax, returning individual characters:
+
+```
+/= "hello"[0]
+```
+
+Output:
+```
+h
+```
+
+## Functions
+
+### Definition
+
+Define functions with the `fn` keyword:
+
+```
+fn add(a, b) {
+    a + b
+}
+```
+
+The last expression in the function body is returned implicitly. An explicit `return` statement is also available for early exit.
+
+```
+fn square(x) {
+    x * x
+}
+/= square(5)
+```
+
+Output:
+```
+25
+```
+
+### Scope
+
+Function parameters are local to the function. The function saves and restores the variable scope:
+
+```
+let x = 10
+fn modify() {
+    x = 5
+}
+modify()
+/= x
+```
+
+Output:
+```
+10
+```
+
+(x inside the function is a separate variable; the outer x is unchanged)
+
+### Recursion
+
+Functions can call themselves recursively, up to a maximum call depth of 256:
+
+```
+fn fib(n) {
+    let a = 0
+    let b = 1
+    let i = 0
+    while (i < n) {
+        let tmp = b
+        b = a + b
+        a = tmp
+        i = i + 1
+    }
+    a
+}
+/= fib(10)
+```
+
+Output:
+```
+55
+```
+
+## Control Flow
+
+### While Loops
+
+Loop while a condition is truthy:
+
+```
+let i = 0
+let sum = 0
+while (i < 10) {
+    sum = sum + i
+    i = i + 1
+}
+/= sum
+```
+
+Output:
+```
+45
+```
+
+Parentheses around the condition are optional (but recommended for clarity).
+
+Loop safety: while loops are limited to 10,000 iterations to prevent infinite loops.
+
+### If/Else
+
+Conditional branching with optional else clause:
+
+```
+let x = 10
+if x > 5 {
+    x = 1
+} else {
+    x = 0
+}
+/= x
+```
+
+Output:
+```
+1
+```
+
+Parentheses around the condition are optional. Else-if chaining works:
+
+```
+let grade = 85
+let letter = "F"
+if grade >= 90 {
+    letter = "A"
+} else if grade >= 80 {
+    letter = "B"
+} else if grade >= 70 {
+    letter = "C"
+}
+/= letter
+```
+
+Output:
+```
+B
+```
+
+### For Loops
+
+Iterate over arrays or ranges:
+
+```
+let sum = 0
+for x in [1, 2, 3, 4, 5] {
+    sum = sum + x
+}
+/= sum
+```
+
+Output:
+```
+15
+```
+
+Using a range expression (`start..end`, exclusive of end):
+
+```
+let sum = 0
+for i in 0..5 {
+    sum = sum + i
+}
+/= sum
+```
+
+Output:
+```
+10
+```
+
+The `range(start, end)` builtin function also works:
+
+```
+let sum = 0
+for i in range(1, 6) {
+    sum = sum + i
+}
+/= sum
+```
+
+Output:
+```
+15
+```
+
+For loops are limited to 10,000 iterations.
+
+### Return Statements
+
+Use `return` for early exit from functions:
+
+```
+fn abs_val(x) {
+    if x < 0 {
+        return -x
+    }
+    x
+}
+/= abs_val(-7)
+```
+
+Output:
+```
+7
+```
+
+Bare `return` (with no value) returns `false`.
+
+## Builtin Functions
+
+### Math Functions
+
+All math functions accept a single number and return a number:
+
+- `sin(x)`: sine
+- `cos(x)`: cosine
+- `tan(x)`: tangent
+- `asin(x)`: arc sine
+- `acos(x)`: arc cosine
+- `atan(x)`: arc tangent
+- `sqrt(x)`: square root
+- `abs(x)`: absolute value
+- `floor(x)`: round down
+- `ceil(x)`: round up
+- `round(x)`: round to nearest integer
+- `ln(x)`: natural logarithm
+- `log(x)`: base-10 logarithm
+
+```
+/= sqrt(16)
+```
+
+Output:
+```
+4
+```
+
+```
+/= abs(-5)
+```
+
+Output:
+```
+5
+```
+
+```
+/= floor(3.7)
+```
+
+Output:
+```
+3
+```
+
+### Range Function
+
+`range(start, end)` returns an array of numbers from start to end (exclusive):
+
+```
+/= range(0, 5)
+```
+
+Output:
+```
+[0, 1, 2, 3, 4]
+```
+
+### Length Function
+
+`len()` returns the length of a string or array:
+
+```
+/= len("hello")
+```
+
+Output:
+```
+5
+```
+
+```
+/= len([1, 2, 3])
+```
+
+Output:
+```
+3
+```
+
+## Truthiness
+
+In boolean contexts (conditions, logical operators), values are truthy or falsy:
+
+- **bool**: `true` is truthy, `false` is falsy
+- **number**: 0 is falsy, all other numbers are truthy
+- **string**: empty string is falsy, all other strings are truthy
+- **array**: empty array is falsy, all other arrays are truthy
+- **void**: falsy
+- **error**: falsy
+
+Truthiness matters for `if`, `while`, `for` conditions and `&&`/`||` operators.
+
+## Ranges
+
+The `..` operator creates an array from start to end (exclusive):
+
+```
+/= 0..5
+```
+
+Output:
+```
+[0, 1, 2, 3, 4]
+```
+
+Ranges are primarily useful with `for` loops and can be stored in variables.
+
+## Negative Numbers
+
+Negative number literals are recognized in appropriate contexts:
+
+```
+/= -5
+```
+
+Output:
+```
+-5
+```
+
+```
+/= 10 + -3
+```
+
+Output:
+```
+7
+```
+
+The unary minus operator also works:
+
+```
+/= -(5 + 3)
+```
+
+Output:
+```
+-8
+```
+
+## Error Handling
+
+Errors are propagated as error values and displayed with an `error:` prefix:
+
+```
+/= undefined_var
+```
+
+Output:
+```
+error: undefined variable 'undefined_var'
+```
+
+```
+/= 1 / 0
+```
+
+Output:
+```
+error: division by zero
+```
+
+Multiple statements execute in sequence, and errors in one statement don't prevent subsequent statements from executing.
+
+## Comments
+
+Single-line comments use `//`:
+
+```
+// This is a comment
+let x = 5
+/= x
+```
+
+Comments can appear at the end of lines too.
+
+## Examples
+
+### Multi-step Calculation
+
+```
+let principal = 1000
+let rate = 0.05
+let years = 10
+let amount = principal * (1 + rate) ^ years
+/= amount
+```
+
+Output:
+```
+1628.89462382...
+```
+
+### Fibonacci
+
+```
+fn fib(n) {
+    let a = 0
+    let b = 1
+    let i = 0
+    while (i < n) {
+        let tmp = b
+        b = a + b
+        a = tmp
+        i = i + 1
+    }
+    a
+}
+/= fib(15)
+```
+
+Output:
+```
+610
+```
+
+### String Building
+
+```
+let greeting = "Hello"
+let name = "World"
+/= greeting + ", " + name + "!"
+```
+
+Output:
+```
+Hello, World!
+```
+
+## Display Formats
+
+### Inline (default)
+
+The standard `/=` prefix displays the result as a single value on the right edge of the editor:
+
+```
+let x = 42
+/= x
+```
+
+Result appears as: `→ 42`
+
+Arrays display inline:
+
+```
+/= [1, 2, 3]
+```
+
+Result: `→ [1, 2, 3]`
+
+### Table (`/=|`)
+
+The `/=|` prefix renders a 2D array (array of arrays) as a visual table overlay:
+
+```
+let data = [["Name", "Age"], ["Alice", 30], ["Bob", 25]]
+/=| data
+```
+
+The first row is treated as the header (rendered bold). Each subsequent row becomes a table row. Non-array values fall back to inline display.
+
+Works with any 2D array:
+
+```
+let matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
+/=| matrix
+```
+
+### Tree (`/=\`)
+
+The `/=\` prefix renders nested data as an indented tree overlay:
+
+```
+let tree = [1, [2, 3], [4, [5, 6]]]
+/=\ tree
+```
+
+Nested arrays are expanded with tree-drawing characters showing depth. Leaf values display inline. The root shows the total element count.
+
+## Limitations
+
+- **No array mutation**: Arrays cannot be modified after creation (no `arr[i] = val`)
+- **No mutable references**: Variable reassignment creates new bindings in the current scope
+- **Maximum call depth**: 256 function calls deep
+- **Maximum loop iterations**: 10,000 iterations per while/for loop
+- **No user-defined types or structs**
+- **No imports or modules**
+- **No pattern matching or destructuring**
+- **No closures or lambdas**
diff --git a/core/src/eval.rs b/core/src/eval.rs
index 75acb81..dbcf9b1 100644
--- a/core/src/eval.rs
+++ b/core/src/eval.rs
@@ -6,6 +6,7 @@ use crate::interp;
 pub struct EvalResult {
     pub line: usize,
     pub result: String,
+    pub format: String,
 }
 
 #[derive(Debug, Clone, Serialize)]
@@ -36,14 +37,23 @@ pub fn evaluate_document(text: &str) -> DocumentResult {
 
     let interp_results = interp::interpret_document(&lines);
     for ir in interp_results {
+        let fmt = match ir.format {
+            interp::EvalFormat::Inline => "inline",
+            interp::EvalFormat::Table => "table",
+            interp::EvalFormat::Tree => "tree",
+        };
         match ir.value {
             Some(interp::Value::Error(e)) => {
                 errors.push(EvalError { line: ir.line, error: e });
             }
             Some(v) => {
-                let s = v.display();
+                let s = match ir.format {
+                    interp::EvalFormat::Table => value_to_table_json(&v),
+                    interp::EvalFormat::Tree => value_to_tree_json(&v),
+                    interp::EvalFormat::Inline => v.display(),
+                };
                 if !s.is_empty() {
-                    results.push(EvalResult { line: ir.line, result: s });
+                    results.push(EvalResult { line: ir.line, result: s, format: fmt.to_string() });
                 }
             }
             None => {}
@@ -53,6 +63,41 @@ pub fn evaluate_document(text: &str) -> DocumentResult {
     DocumentResult { results, errors }
 }
 
+fn value_to_table_json(val: &interp::Value) -> String {
+    match val {
+        interp::Value::Array(rows) => {
+            let table: Vec<Vec<String>> = rows.iter().map(|row| {
+                match row {
+                    interp::Value::Array(cols) => cols.iter().map(|c| c.display()).collect(),
+                    other => vec![other.display()],
+                }
+            }).collect();
+            serde_json::to_string(&table).unwrap_or_else(|_| val.display())
+        }
+        _ => val.display(),
+    }
+}
+
+fn value_to_tree_json(val: &interp::Value) -> String {
+    fn to_json(v: &interp::Value) -> serde_json::Value {
+        match v {
+            interp::Value::Array(items) => {
+                serde_json::Value::Array(items.iter().map(|i| to_json(i)).collect())
+            }
+            interp::Value::Number(n) => {
+                serde_json::Value::Number(
+                    serde_json::Number::from_f64(*n)
+                        .unwrap_or_else(|| serde_json::Number::from(0))
+                )
+            }
+            interp::Value::Bool(b) => serde_json::Value::Bool(*b),
+            interp::Value::Str(s) => serde_json::Value::String(s.clone()),
+            other => serde_json::Value::String(other.display()),
+        }
+    }
+    serde_json::to_string(&to_json(val)).unwrap_or_else(|_| val.display())
+}
+
 pub fn evaluate_line(text: &str) -> Result<String, String> {
     let mut interp = interp::Interpreter::new();
     match interp.eval_expr_str(text) {
@@ -251,4 +296,49 @@ mod tests {
         assert_eq!(result.results.len(), 1);
         assert_eq!(result.results[0].result, "7");
     }
+
+    #[test]
+    fn eval_table_format() {
+        let doc = "let data = [[\"Name\", \"Age\"], [\"Alice\", 30], [\"Bob\", 25]]\n/=| data";
+        let result = evaluate_document(doc);
+        assert_eq!(result.results.len(), 1);
+        assert_eq!(result.results[0].format, "table");
+        let parsed: Vec<Vec<String>> = serde_json::from_str(&result.results[0].result).unwrap();
+        assert_eq!(parsed.len(), 3);
+        assert_eq!(parsed[0], vec!["Name", "Age"]);
+    }
+
+    #[test]
+    fn eval_tree_format() {
+        let doc = "let tree = [1, [2, 3], [4, [5]]]\n/=\\ tree";
+        let result = evaluate_document(doc);
+        assert_eq!(result.results.len(), 1);
+        assert_eq!(result.results[0].format, "tree");
+        let parsed: serde_json::Value = serde_json::from_str(&result.results[0].result).unwrap();
+        assert!(parsed.is_array());
+    }
+
+    #[test]
+    fn eval_inline_format_default() {
+        let doc = "let x = 42\n/= x";
+        let result = evaluate_document(doc);
+        assert_eq!(result.results[0].format, "inline");
+    }
+
+    #[test]
+    fn eval_table_flat_array() {
+        let doc = "/=| [1, 2, 3]";
+        let result = evaluate_document(doc);
+        assert_eq!(result.results.len(), 1);
+        assert_eq!(result.results[0].format, "table");
+    }
+
+    #[test]
+    fn eval_document_json_has_format() {
+        let doc = "let x = 42\n/= x\n/=| [[1, 2], [3, 4]]";
+        let result = evaluate_document(doc);
+        let json = serde_json::to_string(&result).unwrap();
+        assert!(json.contains("\"format\":\"inline\""));
+        assert!(json.contains("\"format\":\"table\""));
+    }
 }
diff --git a/core/src/interp.rs b/core/src/interp.rs
index 177de45..1ec5acf 100644
--- a/core/src/interp.rs
+++ b/core/src/interp.rs
@@ -1158,6 +1158,14 @@ fn apply_type_annotation(val: &Value, ann: Option<&str>) -> Result<Value, String
 pub struct InterpResult {
     pub line: usize,
     pub value: Option<Value>,
+    pub format: EvalFormat,
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum EvalFormat {
+    Inline,
+    Table,
+    Tree,
 }
 
 pub fn interpret_document(lines: &[(usize, &str, bool)]) -> Vec<InterpResult> {
@@ -1174,7 +1182,6 @@ pub fn interpret_document(lines: &[(usize, &str, bool)]) -> Vec<InterpResult> {
 
     for &(idx, content, is_eval) in lines {
         if is_eval {
-            // flush any accumulated block first
             if !block_acc.is_empty() {
                 let block_text = block_acc.join("\n");
                 block_acc.clear();
@@ -1182,20 +1189,27 @@ pub fn interpret_document(lines: &[(usize, &str, bool)]) -> Vec<InterpResult> {
                 match interp.exec_line(&block_text) {
                     Ok(_) => {}
                     Err(e) => {
-                        results.push(InterpResult { line: idx, value: Some(Value::Error(e)) });
+                        results.push(InterpResult { line: idx, value: Some(Value::Error(e)), format: EvalFormat::Inline });
                         continue;
                     }
                 }
             }
 
-            let expr = content.trim().strip_prefix("/=").unwrap_or("").trim();
+            let trimmed = content.trim();
+            let (format, expr) = if let Some(rest) = trimmed.strip_prefix("/=|") {
+                (EvalFormat::Table, rest.trim())
+            } else if let Some(rest) = trimmed.strip_prefix("/=\\") {
+                (EvalFormat::Tree, rest.trim())
+            } else {
+                (EvalFormat::Inline, trimmed.strip_prefix("/=").unwrap_or("").trim())
+            };
             if expr.is_empty() {
-                results.push(InterpResult { line: idx, value: Some(Value::Error("empty expression".into())) });
+                results.push(InterpResult { line: idx, value: Some(Value::Error("empty expression".into())), format });
                 continue;
             }
             match interp.eval_expr_str(expr) {
-                Ok(val) => results.push(InterpResult { line: idx, value: Some(val) }),
-                Err(e) => results.push(InterpResult { line: idx, value: Some(Value::Error(e)) }),
+                Ok(val) => results.push(InterpResult { line: idx, value: Some(val), format }),
+                Err(e) => results.push(InterpResult { line: idx, value: Some(Value::Error(e)), format }),
             }
         } else {
             let trimmed = content.trim();
@@ -1211,17 +1225,15 @@ pub fn interpret_document(lines: &[(usize, &str, bool)]) -> Vec<InterpResult> {
                     block_acc.clear();
                     brace_depth = 0;
                     if let Err(e) = interp.exec_line(&block_text) {
-                        results.push(InterpResult { line: idx, value: Some(Value::Error(e)) });
+                        results.push(InterpResult { line: idx, value: Some(Value::Error(e)), format: EvalFormat::Inline });
                     }
                 }
             } else if opens > closes {
-                // starting a block
                 block_acc.push(trimmed.to_string());
                 brace_depth = opens - closes;
             } else {
-                // single-line cordial statement
                 if let Err(e) = interp.exec_line(trimmed) {
-                    results.push(InterpResult { line: idx, value: Some(Value::Error(e)) });
+                    results.push(InterpResult { line: idx, value: Some(Value::Error(e)), format: EvalFormat::Inline });
                 }
             }
         }
diff --git a/src/AppState.swift b/src/AppState.swift
index 5086fd8..9e7a350 100644
--- a/src/AppState.swift
+++ b/src/AppState.swift
@@ -11,7 +11,7 @@ class AppState: ObservableObject {
             }
         }
     }
-    @Published var evalResults: [Int: String] = [:]
+    @Published var evalResults: [Int: EvalEntry] = [:]
     @Published var noteList: [NoteInfo] = []
     @Published var currentNoteID: UUID
     @Published var selectedNoteIDs: Set<UUID> = []
diff --git a/src/EditorView.swift b/src/EditorView.swift
index eb0fa6f..531ab8f 100644
--- a/src/EditorView.swift
+++ b/src/EditorView.swift
@@ -916,8 +916,8 @@ struct EditorView: View {
         .padding(.top, 4)
     }
 
-    private func offsetEvalResults(_ results: [Int: String]) -> [Int: String] {
-        var shifted: [Int: String] = [:]
+    private func offsetEvalResults(_ results: [Int: EvalEntry]) -> [Int: EvalEntry] {
+        var shifted: [Int: EvalEntry] = [:]
         for (key, val) in results where key > 0 {
             shifted[key - 1] = val
         }
@@ -927,7 +927,7 @@ struct EditorView: View {
 
 struct EditorTextView: NSViewRepresentable {
     @Binding var text: String
-    var evalResults: [Int: String]
+    var evalResults: [Int: EvalEntry]
     var onEvaluate: () -> Void
     var onBackspaceAtStart: (() -> Void)? = nil
 
@@ -1579,8 +1579,13 @@ private func highlightCodeLine(_ line: String, lineRange: NSRange, textStorage:
         return
     }
 
-    // Eval prefix
-    if trimmed.hasPrefix("/=") {
+    if trimmed.hasPrefix("/=|") || trimmed.hasPrefix("/=\\") {
+        let prefix = trimmed.hasPrefix("/=|") ? "/=|" : "/=\\"
+        let prefixRange = (textStorage.string as NSString).range(of: prefix, range: lineRange)
+        if prefixRange.location != NSNotFound {
+            textStorage.addAttribute(.foregroundColor, value: syn.operator, range: prefixRange)
+        }
+    } else if trimmed.hasPrefix("/=") {
         let prefixRange = (textStorage.string as NSString).range(of: "/=", range: lineRange)
         if prefixRange.location != NSNotFound {
             textStorage.addAttribute(.foregroundColor, value: syn.operator, range: prefixRange)
@@ -2201,7 +2206,7 @@ private func resolveLocalImagePath(_ rawPath: String) -> String? {
 
 class LineNumberTextView: NSTextView {
     static let gutterWidth: CGFloat = 50
-    var evalResults: [Int: String] = [:]
+    var evalResults: [Int: EvalEntry] = [:]
 
     override var textContainerOrigin: NSPoint {
         return NSPoint(x: LineNumberTextView.gutterWidth, y: textContainerInset.height)
@@ -2302,11 +2307,18 @@ class LineNumberTextView: NSTextView {
                 numStr.draw(at: NSPoint(x: LineNumberTextView.gutterWidth - numSize.width - 8, y: y))
             }
 
-            if let result = evalResults[lineNumber - 1] {
-                let resultStr = NSAttributedString(string: "\u{2192} \(result)", attributes: resultAttrs)
-                let size = resultStr.size()
-                let rightEdge = visibleRect.maxX
-                resultStr.draw(at: NSPoint(x: rightEdge - size.width - 8, y: y))
+            if let entry = evalResults[lineNumber - 1] {
+                switch entry.format {
+                case .table:
+                    drawTableResult(entry.result, at: y, origin: origin, resultAttrs: resultAttrs)
+                case .tree:
+                    drawTreeResult(entry.result, at: y, origin: origin, resultAttrs: resultAttrs)
+                case .inline:
+                    let resultStr = NSAttributedString(string: "\u{2192} \(entry.result)", attributes: resultAttrs)
+                    let size = resultStr.size()
+                    let rightEdge = visibleRect.maxX
+                    resultStr.draw(at: NSPoint(x: rightEdge - size.width - 8, y: y))
+                }
             }
 
             lineNumber += 1
@@ -2314,6 +2326,165 @@ class LineNumberTextView: NSTextView {
         }
     }
 
+    // MARK: - Table/Tree Rendering
+
+    private func drawTableResult(_ json: String, at y: CGFloat, origin: NSPoint, resultAttrs: [NSAttributedString.Key: Any]) {
+        guard let data = json.data(using: .utf8),
+              let parsed = try? JSONSerialization.jsonObject(with: data),
+              let rows = parsed as? [[Any]] else {
+            let fallback = NSAttributedString(string: "\u{2192} \(json.prefix(40))", attributes: resultAttrs)
+            let size = fallback.size()
+            fallback.draw(at: NSPoint(x: visibleRect.maxX - size.width - 8, y: y))
+            return
+        }
+
+        let palette = Theme.current
+        let font = Theme.gutterFont
+        let headerAttrs: [NSAttributedString.Key: Any] = [
+            .font: NSFontManager.shared.convert(font, toHaveTrait: .boldFontMask),
+            .foregroundColor: palette.teal
+        ]
+        let cellAttrs: [NSAttributedString.Key: Any] = [
+            .font: font,
+            .foregroundColor: palette.subtext0
+        ]
+        let borderColor = palette.surface1
+
+        let stringRows: [[String]] = rows.map { row in
+            row.map { cell in
+                if let s = cell as? String { return s }
+                if let n = cell as? NSNumber { return "\(n)" }
+                return "\(cell)"
+            }
+        }
+        guard !stringRows.isEmpty else { return }
+
+        let colCount = stringRows.map(\.count).max() ?? 0
+        guard colCount > 0 else { return }
+
+        var colWidths = [CGFloat](repeating: 0, count: colCount)
+        for row in stringRows {
+            for (ci, cell) in row.enumerated() where ci < colCount {
+                let w = (cell as NSString).size(withAttributes: cellAttrs).width
+                colWidths[ci] = max(colWidths[ci], w)
+            }
+        }
+
+        let cellPad: CGFloat = 8
+        let rowHeight: CGFloat = font.pointSize + 6
+        let tableWidth = colWidths.reduce(0, +) + cellPad * CGFloat(colCount + 1) + CGFloat(colCount - 1)
+        let tableHeight = rowHeight * CGFloat(stringRows.count) + CGFloat(stringRows.count + 1)
+
+        let rightEdge = visibleRect.maxX
+        let tableX = rightEdge - tableWidth - 12
+        let tableY = y
+
+        let tableRect = NSRect(x: tableX, y: tableY, width: tableWidth, height: tableHeight)
+        palette.mantle.setFill()
+        let path = NSBezierPath(roundedRect: tableRect, xRadius: 4, yRadius: 4)
+        path.fill()
+        borderColor.setStroke()
+        path.lineWidth = 0.5
+        path.stroke()
+
+        var cy = tableY + 2
+        for (ri, row) in stringRows.enumerated() {
+            let attrs = ri == 0 ? headerAttrs : cellAttrs
+            var cx = tableX + cellPad
+            for (ci, cell) in row.enumerated() where ci < colCount {
+                let str = NSAttributedString(string: cell, attributes: attrs)
+                str.draw(at: NSPoint(x: cx, y: cy))
+                cx += colWidths[ci] + cellPad
+            }
+            cy += rowHeight
+
+            if ri == 0 {
+                borderColor.setStroke()
+                let linePath = NSBezierPath()
+                linePath.move(to: NSPoint(x: tableX + 2, y: cy - 1))
+                linePath.line(to: NSPoint(x: tableX + tableWidth - 2, y: cy - 1))
+                linePath.lineWidth = 0.5
+                linePath.stroke()
+            }
+        }
+    }
+
+    private func drawTreeResult(_ json: String, at y: CGFloat, origin: NSPoint, resultAttrs: [NSAttributedString.Key: Any]) {
+        guard let data = json.data(using: .utf8),
+              let root = try? JSONSerialization.jsonObject(with: data) else {
+            let fallback = NSAttributedString(string: "\u{2192} \(json.prefix(40))", attributes: resultAttrs)
+            let size = fallback.size()
+            fallback.draw(at: NSPoint(x: visibleRect.maxX - size.width - 8, y: y))
+            return
+        }
+
+        let palette = Theme.current
+        let font = Theme.gutterFont
+        let nodeAttrs: [NSAttributedString.Key: Any] = [
+            .font: font,
+            .foregroundColor: palette.teal
+        ]
+        let branchAttrs: [NSAttributedString.Key: Any] = [
+            .font: font,
+            .foregroundColor: palette.overlay0
+        ]
+
+        var lines: [(String, Int)] = []
+        func walk(_ node: Any, depth: Int) {
+            if let arr = node as? [Any] {
+                for (i, item) in arr.enumerated() {
+                    let prefix = i == arr.count - 1 ? "\u{2514}" : "\u{251C}"
+                    if item is [Any] {
+                        lines.append(("\(prefix) [\(((item as? [Any])?.count ?? 0))]", depth))
+                        walk(item, depth: depth + 1)
+                    } else {
+                        lines.append(("\(prefix) \(item)", depth))
+                    }
+                }
+            } else {
+                lines.append(("\(node)", depth))
+            }
+        }
+
+        if let arr = root as? [Any] {
+            lines.append(("[\(arr.count)]", 0))
+            walk(root, depth: 1)
+        } else {
+            lines.append(("\(root)", 0))
+        }
+
+        let lineHeight = font.pointSize + 4
+        let indent: CGFloat = 14
+        var maxWidth: CGFloat = 0
+        for (text, depth) in lines {
+            let w = (text as NSString).size(withAttributes: nodeAttrs).width + CGFloat(depth) * indent
+            maxWidth = max(maxWidth, w)
+        }
+
+        let treeHeight = lineHeight * CGFloat(lines.count) + 4
+        let treeWidth = maxWidth + 16
+        let rightEdge = visibleRect.maxX
+        let treeX = rightEdge - treeWidth - 8
+        let treeY = y
+
+        let treeRect = NSRect(x: treeX, y: treeY, width: treeWidth, height: treeHeight)
+        palette.mantle.setFill()
+        let path = NSBezierPath(roundedRect: treeRect, xRadius: 4, yRadius: 4)
+        path.fill()
+        palette.surface1.setStroke()
+        path.lineWidth = 0.5
+        path.stroke()
+
+        var cy = treeY + 2
+        for (text, depth) in lines {
+            let x = treeX + 8 + CGFloat(depth) * indent
+            let attrs = depth == 0 ? nodeAttrs : branchAttrs
+            let str = NSAttributedString(string: text, attributes: attrs)
+            str.draw(at: NSPoint(x: x, y: cy))
+            cy += lineHeight
+        }
+    }
+
     // MARK: - Paste (image from clipboard)
 
     override func paste(_ sender: Any?) {
diff --git a/src/RustBridge.swift b/src/RustBridge.swift
index 0ae2840..45e2b2e 100644
--- a/src/RustBridge.swift
+++ b/src/RustBridge.swift
@@ -6,6 +6,17 @@ struct NoteInfo: Identifiable {
     var lastModified: Date
 }
 
+enum EvalFormat: String {
+    case inline
+    case table
+    case tree
+}
+
+struct EvalEntry {
+    let result: String
+    let format: EvalFormat
+}
+
 class RustBridge {
     static let shared = RustBridge()
 
@@ -41,7 +52,7 @@ class RustBridge {
         return str
     }
 
-    func evaluate(_ id: UUID) -> [Int: String] {
+    func evaluate(_ id: UUID) -> [Int: EvalEntry] {
         guard let ptr = docs[id] else { return [:] }
         guard let cstr = swiftly_doc_evaluate(ptr) else { return [:] }
         let json = String(cString: cstr)
@@ -118,14 +129,15 @@ class RustBridge {
         return str
     }
 
-    private func parseEvalJSON(_ json: String) -> [Int: String] {
+    private func parseEvalJSON(_ json: String) -> [Int: EvalEntry] {
         guard let data = json.data(using: .utf8) else { return [:] }
         guard let obj = try? JSONSerialization.jsonObject(with: data) as? [String: Any] else { return [:] }
         guard let results = obj["results"] as? [[String: Any]] else { return [:] }
-        var dict: [Int: String] = [:]
+        var dict: [Int: EvalEntry] = [:]
         for item in results {
             if let line = item["line"] as? Int, let result = item["result"] as? String {
-                dict[line] = result
+                let fmt = EvalFormat(rawValue: item["format"] as? String ?? "inline") ?? .inline
+                dict[line] = EvalEntry(result: result, format: fmt)
             }
         }
         return dict