Downgrade text from a language feature to a filter

- no longer cached, could change this

README.md

@@ -148,7 +148,7 @@ For example, take the input element `<p id="meowing">Meow mrrp meow meow!</p>`.
 
 ```
 meow_element: #meowing {
-  meows: $text;
+  meows: $element | text();
 };
 ```
 
@@ -177,7 +177,7 @@ this scrp
 ```
 parent: #parent {
   child: p {
-    child_text: $text;
+    child_text: $element | text();
   }
 };
 ```

doc/src/quick_start.md

@@ -19,11 +19,11 @@ A `scrapelect` program stored in a `name.scrp` file.  Let's create and edit the
 
 ```scrp
 title: .mw-page-title-main {
-  content: $text;
+  content: $element | text();
 };
 
 headings: .mw-heading > * {
-  content: $text;
+  content: $element | text();
 }*;
 ```
 

doc/theme/highlight.js

@@ -3358,7 +3358,7 @@ if (typeof exports === "object" && typeof module !== "undefined") {
   function scrp(hljs) {
     return {
       case_insensitive: false,
-      keywords: ["text", "element"],
+      keywords: ["element"],
       contains: [hljs.C_LINE_COMMENT_MODE, hljs.QUOTE_STRING_MODE],
     };
   }

examples/outputs/abc.snap

@@ -7,6 +7,6 @@ expression: result
     "link": {
       "parent": "Hello, world!"
     },
-    "txt": "Hello, world!"
+    "text": "Hello, world!"
   }
 }

examples/outputs/qualifiers.snap

@@ -6,36 +6,36 @@ expression: result
   "items": [
     {
       "special": null,
-      "txt": "Hello! 1"
+      "text": "Hello! 1"
     },
     {
       "special": "special!",
-      "txt": "Hello! 2"
+      "text": "Hello! 2"
     },
     {
       "special": null,
-      "txt": "Hello! 3"
+      "text": "Hello! 3"
     },
     {
       "special": null,
-      "txt": "Hello! 4"
+      "text": "Hello! 4"
     },
     {
       "special": null,
-      "txt": "Hello! 5"
+      "text": "Hello! 5"
     },
     {
       "special": null,
-      "txt": "Hello! 6"
+      "text": "Hello! 6"
     },
     {
       "special": null,
-      "txt": "Hello! 7"
+      "text": "Hello! 7"
     }
   ],
   "sixth": {
     "special": null,
-    "txt": "Hello! 6"
+    "text": "Hello! 6"
   },
   "specials": [
     null,

examples/scrps/abc.scrp

@@ -1,8 +1,8 @@
 header: h2 {
-    txt: $text;
+    text: $element | text();
 
     link: a {
         child: $element;
-        parent: $txt;
+        parent: $text;
     };
 };

examples/scrps/qualifiers.scrp

@@ -1,6 +1,6 @@
 items: li {
-    special: .special { txt: $text; }? | take(key: "txt")?;
-    txt: $text;
+    special: .special { text: $element | text(); }? | take(key: "text")?;
+    text: $element | text();
 }*;
 
 specials: $items | take(key: "special")*;

examples/scrps/recurser.scrp

@@ -3,5 +3,5 @@ link: a {
 } | take(key: "href");
 
 new_page: <$link> h1 {
-    content: $text;
+    content: $element | text();
 };

examples/scrps/relative.scrp

@@ -3,5 +3,5 @@ href: a {
 } | take(key: "href");
 
 relative: <$href> #success {
-    x: $text;
+    x: $element | text();
 } | take(key: "x");

src/interpreter/filter/builtin.rs

@@ -376,6 +376,27 @@ pub fn truthy<'doc>(value: PValue<'doc>) -> anyhow::Result<PValue<'doc>> {
     Ok(Value::Bool(truthy))
 }
 
+/// Signature: `value: Element | text(): String`
+///
+/// Returns the text contained inside this element.  Note that this is just
+/// direct text, not the text of any descendent elements.
+///
+/// # Examples
+///
+/// -  Let `element` = `<div>Hello...<span>inner</span>...world!</div>`
+///   - Then `$element | text()` is `"Hello......world!"`
+/// - `<img /> | text()` is `""`
+#[filter_fn]
+pub fn text<'doc>(value: scraper::ElementRef<'doc>) -> anyhow::Result<PValue<'doc>> {
+    Ok(Value::String(
+        value
+            .children()
+            .filter_map(|x| x.value().as_text().map(|text| &*text.text))
+            .collect::<String>()
+            .into(),
+    ))
+}
+
 macro_rules! build_map {
     ($(
         $id: ident,
@@ -407,6 +428,7 @@ pub static FILTERS: LazyLock<BTreeMap<&'static str, Box<dyn FilterDyn + Send + S
             split,
             eq,
             is_in,
+            text,
         }
         .into_iter()
         .collect()

src/interpreter/mod.rs

@@ -1,4 +1,4 @@
-use std::{borrow::Cow, cell::OnceCell, collections::BTreeMap, sync::Arc};
+use std::{borrow::Cow, collections::BTreeMap, sync::Arc};
 
 use anyhow::Context;
 use execution_mode::ExecutionMode;
@@ -86,7 +86,6 @@ impl<'ast> From<DataVariables<'ast>> for Value {
 pub struct ElementContext<'ast, 'ctx> {
     variables: Variables<'ast, 'ctx>,
     element: scraper::ElementRef<'ctx>,
-    text: OnceCell<Arc<str>>,
     parent: Option<&'ctx ElementContext<'ast, 'ctx>>,
     url: Url,
 }
@@ -162,7 +161,6 @@ impl<'ast> Interpreter<'ast> {
             element,
             parent,
             variables: Variables::default(),
-            text: OnceCell::new(),
             url,
         };
 
@@ -264,7 +262,6 @@ impl<'ast> Interpreter<'ast> {
                     let mut inner_scope = ElementContext {
                         element: ctx.element,
                         variables: Variables::default(),
-                        text: OnceCell::new(),
                         parent: Some(ctx),
                         url: ctx.url.clone(),
                     };
@@ -325,13 +322,6 @@ impl<'ast, 'ctx> ElementContext<'ast, 'ctx> {
     pub fn get_var(&self, id: &str) -> anyhow::Result<EValue<'ctx>> {
         match id {
             "element" => Ok(self.element.into()),
-            "text" => Ok(Value::String(Arc::clone(self.text.get_or_init(|| {
-                self.element
-                    .children()
-                    .filter_map(|x| x.value().as_text().map(|x| &**x))
-                    .collect::<String>()
-                    .into()
-            })))),
             var => match self.variables.0.get(var) {
                 Some(var) => Ok(var.clone()),
                 None => self
@@ -344,7 +334,7 @@ impl<'ast, 'ctx> ElementContext<'ast, 'ctx> {
 
     pub fn set_var(&mut self, name: Cow<'ast, str>, value: EValue<'ctx>) -> anyhow::Result<()> {
         match &*name {
-            immutable @ ("element" | "text") => {
+            immutable @ "element" => {
                 anyhow::bail!("Can't assign to immutable variable `{immutable}`")
             }
             _ => self.variables.0.insert(name, value),
@@ -441,11 +431,11 @@ mod tests {
         let output = super::interpret_string_harness(
             r#"
             h3: h3 {
-                txt: $text;
+                text: $element | text();
 
                 a: a {
-                    child: $text;
-                    parent: $txt;
+                    child: $element | text();
+                    parent: $text;
                 }*;
                 div: div {}?;
             };
@@ -488,7 +478,7 @@ mod tests {
         );
 
         assert!(
-            match d.get("txt") {
+            match d.get("text") {
                 Some(String(x)) => &**x == "Hello,parent!",
                 _ => false,
             },