Update vegalite theme (#133)

Author: thomasp85

src/parser/builder.rs

@@ -37,10 +37,40 @@ fn extract_name_value_nodes<'a>(node: &'a Node<'a>, context: &str) -> Result<(No
     Ok((name_node, value_node))
 }
 
-/// Parse a string node, removing quotes
+/// Parse a string node, removing quotes and processing escape sequences
 fn parse_string_node(node: &Node, source: &SourceTree) -> String {
     let text = source.get_text(node);
-    text.trim_matches(|c| c == '\'' || c == '"').to_string()
+    let unquoted = text.trim_matches(|c| c == '\'' || c == '"');
+    process_escape_sequences(unquoted)
+}
+
+/// Process escape sequences in a string (e.g., \n, \t, \\, \')
+fn process_escape_sequences(s: &str) -> String {
+    let mut result = String::with_capacity(s.len());
+    let mut chars = s.chars().peekable();
+
+    while let Some(c) = chars.next() {
+        if c == '\\' {
+            match chars.next() {
+                Some('n') => result.push('\n'),
+                Some('t') => result.push('\t'),
+                Some('r') => result.push('\r'),
+                Some('\\') => result.push('\\'),
+                Some('\'') => result.push('\''),
+                Some('"') => result.push('"'),
+                Some(other) => {
+                    // Unknown escape sequence - keep as-is
+                    result.push('\\');
+                    result.push(other);
+                }
+                None => result.push('\\'), // Trailing backslash
+            }
+        } else {
+            result.push(c);
+        }
+    }
+
+    result
 }
 
 /// Parse a number node into f64

src/writer/vegalite/mod.rs

@@ -358,6 +358,65 @@ impl VegaLiteWriter {
             schema: "https://vega.github.io/schema/vega-lite/v6.json".to_string(),
         }
     }
+
+    /// Build default Vega-Lite config matching ggplot2's theme_gray()
+    ///
+    /// Font sizes converted from ggplot2 points to pixels (1 pt ≈ 1.33 px at 96 DPI):
+    /// - axis.text: 8.8 pts (rel(0.8) × 11) → 12 px
+    /// - axis.title: 11 pts → 15 px
+    /// - legend.text: 8.8 pts → 12 px
+    /// - legend.title: 11 pts → 15 px
+    /// - plot.title: 13.2 pts (rel(1.2) × 11) → 18 px
+    /// - tick size: ~2.75 pts → 4 px
+    fn default_theme_config(&self) -> Value {
+        json!({
+            "view": {
+                "stroke": null,
+                "fill": "#EBEBEB"
+            },
+            "axis": {
+                "domain": false,
+                "grid": true,
+                "gridColor": "#FFFFFF",
+                "gridWidth": 1,
+                "tickColor": "#333333",
+                "tickSize": 4,
+                "labelColor": "#4D4D4D",
+                "labelFontSize": 12,
+                "titleColor": "#000000",
+                "titleFontSize": 15,
+                "titleFontWeight": "normal",
+                "titlePadding": 10
+            },
+            "legend": {
+                "labelColor": "#4D4D4D",
+                "labelFontSize": 12,
+                "titleColor": "#000000",
+                "titleFontSize": 15,
+                "titleFontWeight": "normal",
+                "titlePadding": 8,
+                "rowPadding": 6
+            },
+            "title": {
+                "color": "#000000",
+                "fontSize": 18,
+                "fontWeight": "normal",
+                "subtitleColor": "#4D4D4D",
+                "subtitleFontSize": 15,
+                "subtitleFontWeight": "normal",
+                "anchor": "start",
+                "frame": "group",
+                "offset": 10
+            },
+            "header": {
+                "labelColor": "#000000",
+                "labelFontSize": 15,
+                "labelFontWeight": "normal",
+                "labelPadding": 5,
+                "title": null
+            }
+        })
+    }
 }
 
 impl Default for VegaLiteWriter {
@@ -442,7 +501,10 @@ impl Writer for VegaLiteWriter {
             apply_faceting(&mut vl_spec, facet, facet_df);
         }
 
-        // 11. Serialize
+        // 11. Add default theme config (ggplot2-like gray theme)
+        vl_spec["config"] = self.default_theme_config();
+
+        // 12. Serialize
         serde_json::to_string_pretty(&vl_spec).map_err(|e| {
             GgsqlError::WriterError(format!("Failed to serialize Vega-Lite JSON: {}", e))
         })

tree-sitter-ggsql/grammar.js

@@ -870,7 +870,7 @@ module.exports = grammar({
       )
     )),
 
-    string: $ => seq("'", repeat(choice(/[^'\\]/, seq('\\', /.*/))), "'"),
+    string: $ => seq("'", repeat(choice(/[^'\\]/, /\\./)), "'"),
 
     boolean: $ => choice('true', 'false'),