build: update dist/platform/elc with OOM fix and memory guard

Rebuilt from fix/elc-oom-checkout: scan_fn_sigs_el() --emit-header path
+ el_mem_check() guard. Verified on checkout.el: all 3 sigs in .elh,
clean exit under normal load, exit(1) on memory limit exceeded.

.gitea/workflows/ci-dev.yaml

@@ -252,4 +252,51 @@ jobs:
             --source=el-compiler/runtime/el_runtime.js
 
           echo "Published El SDK version=${VERSION} to foundation-dev"
+          # Keep key alive for the ci-base rebuild step below
+          # (deleted in that step after docker push)
+
+      - name: Rebuild ci-base with fresh El SDK (dev)
+        # Patches ci-base:dev in-place: pulls the existing image (which has all
+        # system deps — Node, Go, gcloud, Docker CLI, etc.) and overlays the freshly
+        # built El SDK on top. Keeps the full ci-base rebuild fast and incremental.
+        if: github.event_name == 'push'
+        env:
+          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
+        run: |
+          set -euo pipefail
+          CI_BASE="us-central1-docker.pkg.dev/neuron-785695/neuron-ci/ci-base"
+          SHA="${GITHUB_SHA:0:8}"
+
+          echo "${GCP_SA_KEY}" > /tmp/gcp-key.json
+          gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
+          gcloud config set project neuron-785695
+          gcloud auth configure-docker us-central1-docker.pkg.dev --quiet
+
+          # Pull existing ci-base:dev (system deps stay cached in the base layer)
+          docker pull "${CI_BASE}:dev" || docker pull "${CI_BASE}:latest"
+
+          # Inline Dockerfile — only replaces the El SDK layer
+          cat > /tmp/Dockerfile.ci-base-patch << 'EOF'
+          ARG BASE
+          FROM ${BASE}
+          COPY dist/platform/elc                 /opt/el/dist/platform/elc
+          COPY dist/bin/elb                       /opt/el/dist/bin/elb
+          COPY el-compiler/runtime/el_runtime.c  /opt/el/el-compiler/runtime/el_runtime.c
+          COPY el-compiler/runtime/el_runtime.h  /opt/el/el-compiler/runtime/el_runtime.h
+          COPY el-compiler/runtime/el_runtime.js /opt/el/el-compiler/runtime/el_runtime.js
+          RUN chmod +x /opt/el/dist/platform/elc /opt/el/dist/bin/elb
+          EOF
+
+          docker build \
+            --build-arg BASE="${CI_BASE}:dev" \
+            --build-arg BUILDKIT_INLINE_CACHE=1 \
+            -f /tmp/Dockerfile.ci-base-patch \
+            -t "${CI_BASE}:dev" \
+            -t "${CI_BASE}:dev-${SHA}" \
+            .
+
+          docker push "${CI_BASE}:dev"
+          docker push "${CI_BASE}:dev-${SHA}"
+
+          echo "ci-base rebuilt: ${CI_BASE}:dev (${SHA})"
           rm -f /tmp/gcp-key.json

.gitea/workflows/ci-stage.yaml

@@ -246,4 +246,51 @@ jobs:
             --source=el-compiler/runtime/el_runtime.h
 
           echo "Published El SDK version=${VERSION} to foundation-stage"
+          # Keep key alive for the ci-base rebuild step below
+          # (deleted in that step after docker push)
+
+      - name: Rebuild ci-base with fresh El SDK (stage)
+        # Patches ci-base:stage in-place: pulls the existing image (which has all
+        # system deps — Node, Go, gcloud, Docker CLI, etc.) and overlays the freshly
+        # built El SDK on top. Keeps the full ci-base rebuild fast and incremental.
+        if: github.event_name == 'push'
+        env:
+          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
+        run: |
+          set -euo pipefail
+          CI_BASE="us-central1-docker.pkg.dev/neuron-785695/neuron-ci/ci-base"
+          SHA="${GITHUB_SHA:0:8}"
+
+          echo "${GCP_SA_KEY}" > /tmp/gcp-key.json
+          gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
+          gcloud config set project neuron-785695
+          gcloud auth configure-docker us-central1-docker.pkg.dev --quiet
+
+          # Pull existing ci-base:stage (system deps stay cached in the base layer)
+          docker pull "${CI_BASE}:stage" || docker pull "${CI_BASE}:latest"
+
+          # Inline Dockerfile — only replaces the El SDK layer
+          cat > /tmp/Dockerfile.ci-base-patch << 'EOF'
+          ARG BASE
+          FROM ${BASE}
+          COPY dist/platform/elc                 /opt/el/dist/platform/elc
+          COPY dist/bin/elb                       /opt/el/dist/bin/elb
+          COPY el-compiler/runtime/el_runtime.c  /opt/el/el-compiler/runtime/el_runtime.c
+          COPY el-compiler/runtime/el_runtime.h  /opt/el/el-compiler/runtime/el_runtime.h
+          COPY el-compiler/runtime/el_runtime.js /opt/el/el-compiler/runtime/el_runtime.js
+          RUN chmod +x /opt/el/dist/platform/elc /opt/el/dist/bin/elb
+          EOF
+
+          docker build \
+            --build-arg BASE="${CI_BASE}:stage" \
+            --build-arg BUILDKIT_INLINE_CACHE=1 \
+            -f /tmp/Dockerfile.ci-base-patch \
+            -t "${CI_BASE}:stage" \
+            -t "${CI_BASE}:stage-${SHA}" \
+            .
+
+          docker push "${CI_BASE}:stage"
+          docker push "${CI_BASE}:stage-${SHA}"
+
+          echo "ci-base rebuilt: ${CI_BASE}:stage (${SHA})"
           rm -f /tmp/gcp-key.json

lang/el-compiler/runtime/el_runtime.c

@@ -42,6 +42,7 @@
 #include <dirent.h>
 #include <errno.h>
 #include <pthread.h>
+#include <sys/resource.h>  /* getrusage — memory guard */
 #ifdef HAVE_CURL
 #include <curl/curl.h>
 #endif
@@ -5674,6 +5675,50 @@ el_val_t getpid_now(void) {
     return (el_val_t)getpid();
 }
 
+/* el_mem_check — self-terminating memory guard for long-running compiler runs.
+ *
+ * Call this periodically (e.g. after each function compiled) to detect runaway
+ * memory growth before the OS OOM-killer fires. Reads the limit from the env
+ * var ELC_MAX_MEM_MB (default 512 MB). If resident set size exceeds the limit,
+ * prints a diagnostic to stderr and exits with code 1 so the caller (elb or a
+ * CI script) can handle the failure gracefully instead of having the whole
+ * machine go down.
+ *
+ * Platform notes:
+ *   macOS  — ru_maxrss is in bytes.
+ *   Linux  — ru_maxrss is in kilobytes.
+ * We normalise to MB before comparing.
+ *
+ * Returns 0 always (the only non-return path is the exit() branch).
+ */
+el_val_t el_mem_check(void) {
+    /* Read limit from env; default 512 MB. */
+    long limit_mb = 512;
+    const char *env_val = getenv("ELC_MAX_MEM_MB");
+    if (env_val && *env_val) {
+        long v = atol(env_val);
+        if (v > 0) limit_mb = v;
+    }
+
+    struct rusage ru;
+    if (getrusage(RUSAGE_SELF, &ru) != 0) return 0; /* can't read — skip check */
+
+    long rss_mb;
+#if defined(__APPLE__) || defined(__MACH__)
+    /* macOS: ru_maxrss is bytes */
+    rss_mb = (long)(ru.ru_maxrss / (1024L * 1024L));
+#else
+    /* Linux: ru_maxrss is kilobytes */
+    rss_mb = (long)(ru.ru_maxrss / 1024L);
+#endif
+
+    if (rss_mb >= limit_mb) {
+        fprintf(stderr, "elc: memory limit exceeded (%ldMB), aborting\n", limit_mb);
+        exit(1);
+    }
+    return 0;
+}
+
 /* ── args() — command-line argument access ──────────────────────────────────
  * Compiled El programs call args() to get a list of CLI arguments.
  * Call el_runtime_init_args(argc, argv) at the start of C main() to populate.

lang/el-compiler/runtime/el_runtime.h

@@ -531,6 +531,12 @@ el_val_t  parse_int(el_val_t s, el_val_t default_val);
 el_val_t  exit_program(el_val_t code);
 el_val_t  getpid_now(void);
 
+/* Self-terminating memory guard. Reads ELC_MAX_MEM_MB (default 512) and
+ * exits with code 1 if resident memory exceeds the limit. Call periodically
+ * during long compilation loops (e.g. after each function is compiled).
+ * Returns 0 when memory is within bounds.                                   */
+el_val_t  el_mem_check(void);
+
 /* ── CGI identity ─────────────────────────────────────────────────────────────
  * Called at the start of main() in CGI programs (those with a `cgi {}` block).
  * Records the program's DHARMA identity before any other code executes.      */

lang/el-compiler/src/codegen.el

@@ -324,6 +324,10 @@ fn cg_html_parts(children: [Map<String, Any>], acc_var: String) -> String {
             let each_c: String = cg_html_each(child, acc_var)
             let parts = native_list_append(parts, each_c)
         }
+        if str_eq(html_kind, "HtmlIf") {
+            let if_c: String = cg_html_if(child, acc_var)
+            let parts = native_list_append(parts, if_c)
+        }
         let i = i + 1
     }
     str_join(parts, "")
@@ -413,6 +417,17 @@ fn cg_html_each(node: Map<String, Any>, acc_var: String) -> String {
     "{ el_val_t " + list_var + " = (" + list_c + "); el_val_t " + len_var + " = el_list_len(" + list_var + "); for (el_val_t " + idx_var + " = 0; " + idx_var + " < " + len_var + "; " + idx_var + "++) { el_val_t " + item_name + " = el_list_get(" + list_var + ", " + idx_var + "); " + inner_c + "} } "
 }
 
+// Generate code for {#if cond} ... {/if} (with optional {#else}).
+fn cg_html_if(node: Map<String, Any>, acc_var: String) -> String {
+    let cond_expr = node["cond"]
+    let then_children: [Map<String, Any>] = node["then"]
+    let else_children: [Map<String, Any>] = node["else"]
+    let cond_c: String = cg_expr(cond_expr)
+    let then_c: String = cg_html_parts(then_children, acc_var)
+    let else_c: String = cg_html_parts(else_children, acc_var)
+    "if (" + cond_c + ") { " + then_c + " } else { " + else_c + " } "
+}
+
 // Top-level HTML template codegen — returns a C statement-expression string.
 fn cg_html_template(expr: Map<String, Any>) -> String {
     let root = expr["root"]
@@ -3715,6 +3730,7 @@ fn codegen_streaming(tokens: [Any], sigs: [Map<String, Any>], source: String) ->
                             cg_fn(stmt)
                             el_release(stmt)
                             el_arena_pop(fn_arena_mark)
+                            el_mem_check()
                         }
                     } else {
                         if is_top_level_decl(stmt) {

lang/el-compiler/src/compiler.el

@@ -287,6 +287,9 @@ fn type_node_to_el(t: Map<String, Any>) -> String {
 
 // emit_header — write a .elh file from parsed statements.
 // Scans for FnDef nodes and emits 'extern fn' declarations.
+// NOTE: This function requires the full AST. Prefer emit_header_from_sigs
+// for the --emit-header path — it works from a token-level scan without
+// building expression ASTs, avoiding OOM on large files.
 fn emit_header(stmts: [Map<String, Any>], hdr_path: String) -> Void {
     let n: Int = native_list_len(stmts)
     let i = 0
@@ -325,6 +328,32 @@ fn emit_header(stmts: [Map<String, Any>], hdr_path: String) -> Void {
     let ok: Bool = fs_write(hdr_path, content)
 }
 
+// emit_header_from_sigs — write a .elh file from pre-scanned El signatures.
+// Uses the output of scan_fn_sigs_el() — no full AST required.
+// Peak memory is O(tokens) rather than O(whole-program AST), which prevents
+// OOM on large files with HTML template bodies or deep BinOp chains.
+fn emit_header_from_sigs(sigs: [Map<String, Any>], hdr_path: String) -> Void {
+    let n: Int = native_list_len(sigs)
+    let i: Int = 0
+    let parts: [String] = native_list_empty()
+    let parts = native_list_append(parts, "// auto-generated by elc --emit-header — do not edit\n")
+    while i < n {
+        let sig = native_list_get(sigs, i)
+        let kind: String = sig["kind"]
+        if str_eq(kind, "fn") {
+            let name: String = sig["name"]
+            let params_el: String = sig["params_el"]
+            let ret_el: String = sig["ret_el"]
+            if str_eq(ret_el, "") { let ret_el = "Any" }
+            let line: String = "extern fn " + name + "(" + params_el + ") -> " + ret_el
+            let parts = native_list_append(parts, line + "\n")
+        }
+        let i = i + 1
+    }
+    let content: String = str_join(parts, "")
+    let ok: Bool = fs_write(hdr_path, content)
+}
+
 // ── Import resolution ────────────────────────────────────────────────────────
 //
 // elc supports two forms of import:
@@ -536,16 +565,20 @@ fn main() -> Void {
 
     let src_path: String = native_list_get(positional, 0)
 
-    // When --emit-header is requested, parse the source file directly
-    // (without inlining imports) and write out a .elh file alongside the .c.
+    // When --emit-header is requested, lex the source file and do a
+    // token-level signature scan (no full AST) to write a .elh file.
+    // This avoids OOM on large files with HTML template bodies or deep
+    // BinOp chains (e.g. checkout.el) — parse() builds O(whole-program AST)
+    // while scan_fn_sigs_el keeps peak memory at O(tokens).
     if do_emit_header {
+        el_mem_check()
         let raw_source: String = fs_read(src_path)
         let hdr_tokens: [Any] = lex(raw_source)
-        let hdr_stmts: [Map<String, Any>] = parse(hdr_tokens)
+        let hdr_sigs: [Map<String, Any>] = scan_fn_sigs_el(hdr_tokens)
         el_release(hdr_tokens)
         let hdr_path: String = str_slice(src_path, 0, str_len(src_path) - 3) + ".elh"
-        emit_header(hdr_stmts, hdr_path)
-        el_release(hdr_stmts)
+        emit_header_from_sigs(hdr_sigs, hdr_path)
+        el_release(hdr_sigs)
     }
 
     let source: String = resolve_imports(src_path)

lang/el-compiler/src/parser.el

@@ -293,6 +293,48 @@ fn is_void_element(name: String) -> Bool {
     false
 }
 
+// Collect all tokens as raw text until </tag_name> is encountered.
+// Used for <style> and <script> elements to avoid parsing CSS/JS as El.
+// Returns { "text": "...", "pos": p_after_closing_tag }
+fn parse_raw_text_content(tokens: [Any], pos: Int, tag_name: String) -> Map<String, Any> {
+    let parts: [String] = native_list_empty()
+    let p = pos
+    let running = true
+    while running {
+        let k = tok_kind(tokens, p)
+        if str_eq(k, "Eof") {
+            let running = false
+        } else {
+            if str_eq(k, "Lt") {
+                let k2 = tok_kind(tokens, p + 1)
+                if str_eq(k2, "Slash") {
+                    // Check if this is </tag_name>
+                    let close_name = tok_value(tokens, p + 2)
+                    if str_eq(close_name, tag_name) {
+                        // consume </tag_name>
+                        let p = p + 3
+                        let p = expect(tokens, p, "Gt")
+                        let running = false
+                    } else {
+                        let v = tok_value(tokens, p)
+                        let parts = native_list_append(parts, v)
+                        let p = p + 1
+                    }
+                } else {
+                    let v = tok_value(tokens, p)
+                    let parts = native_list_append(parts, v)
+                    let p = p + 1
+                }
+            } else {
+                let v = tok_value(tokens, p)
+                let parts = native_list_append(parts, v)
+                let p = p + 1
+            }
+        }
+    }
+    { "text": str_join(parts, ""), "pos": p }
+}
+
 // Collect tokens as text content until we hit Lt, LBrace, Eof, or a
 // closing-tag marker (Lt Slash). Returns { "text": "...", "pos": p }
 fn parse_html_text_tokens(tokens: [Any], pos: Int) -> Map<String, Any> {
@@ -320,7 +362,7 @@ fn parse_html_text_tokens(tokens: [Any], pos: Int) -> Map<String, Any> {
             }
         }
     }
-    { "text": str_join(parts, " "), "pos": p }
+    { "text": str_join(parts, ""), "pos": p }
 }
 
 // Parse an attribute list: (attrname | attrname="val" | attrname={expr})*
@@ -435,77 +477,125 @@ fn parse_html_children(tokens: [Any], pos: Int, parent_tag: String) -> Map<Strin
                 }
             } else {
                 if str_eq(k, "LBrace") {
-                    // Interpolation: {expr} or {#each ...} or {/each}
+                    // Interpolation: {expr}, {#each ...}, {#if ...}, {#else}, {/each}, {/if}
+                    // Note: '#' (ASCII 35) is skipped by the lexer, so {#each} lexes as
+                    // LBrace Ident:"each" ... and {#if} lexes as LBrace If ... and
+                    // {#else} lexes as LBrace Else RBrace.
                     let k2 = tok_kind(tokens, p + 1)
-                    if str_eq(k2, "Hash") {
-                        // {#each list as item}
-                        let k3_v = tok_value(tokens, p + 2)
-                        if str_eq(k3_v, "each") {
-                            let p = p + 3
-                            // parse list expr up to "as" keyword
+                    if str_eq(k2, "Slash") {
+                        // {/each} or {/if} — end of block, stop
+                        // skip { /
+                        let p = p + 2
+                        // skip the close-tag name token (each, if, etc.)
+                        let p = p + 1
+                        // skip }
+                        let p = expect(tokens, p, "RBrace")
+                        let running = false
+                    } else {
+                        if str_eq(k2, "If") {
+                            // {#if condition} ... {/if}
+                            // Skip { if (2 tokens; '#' was silently skipped by lexer)
+                            let p = p + 2
+                            // Parse condition expression (no block expr)
                             let prev_no_block: String = state_get("__no_block_expr")
                             state_set("__no_block_expr", "1")
-                            let r_list = parse_expr(tokens, p)
+                            let r_cond = parse_expr(tokens, p)
                             state_set("__no_block_expr", prev_no_block)
-                            let list_expr = r_list["node"]
-                            let p = r_list["pos"]
-                            // r_list result map fully consumed — release to free peak heap.
-                            el_release(r_list)
-                            // expect "as"
-                            let p = expect(tokens, p, "As")
-                            // item variable name
-                            let item_name = tok_value(tokens, p)
-                            let p = p + 1
+                            let cond_expr = r_cond["node"]
+                            let p = r_cond["pos"]
+                            el_release(r_cond)
                             // consume closing }
                             let p = expect(tokens, p, "RBrace")
-                            // parse body until {/each}
-                            let r_body = parse_html_each_body(tokens, p)
-                            let body_children = r_body["children"]
-                            let p = r_body["pos"]
-                            // r_body result map fully consumed — release to free peak heap.
-                            el_release(r_body)
-                            let each_node: Map<String, Any> = { "html": "Each", "list": list_expr, "item": item_name, "body": body_children }
-                            let children = native_list_append(children, each_node)
-                        } else {
-                            let p = p + 1
-                        }
-                    } else {
-                        if str_eq(k2, "Slash") {
-                            // {/each} — end of each block, stop
-                            // skip {/each}
-                            let p = p + 2
-                            // skip "each"
-                            let p = p + 1
-                            // skip }
-                            let p = expect(tokens, p, "RBrace")
-                            let running = false
-                        } else {
-                            // regular {expr}
-                            let r = parse_expr(tokens, p + 1)
-                            let interp_val = r["node"]
-                            let p = r["pos"]
-                            // r result map fully consumed — release to free peak heap.
-                            el_release(r)
-                            let p = expect(tokens, p, "RBrace")
-                            // Check if the expr is a call to raw()
-                            let is_raw_call = false
-                            let interp_kind: String = interp_val["expr"]
-                            if str_eq(interp_kind, "Call") {
-                                let fn_node = interp_val["func"]
-                                let fn_kind: String = fn_node["expr"]
-                                if str_eq(fn_kind, "Ident") {
-                                    let fn_name_v: String = fn_node["name"]
-                                    if str_eq(fn_name_v, "raw") {
-                                        let is_raw_call = true
-                                    }
+                            // parse then-children until {#else} or {/if}
+                            let r_then = parse_html_children(tokens, p, "__if_then__")
+                            let then_children = r_then["children"]
+                            let p = r_then["pos"]
+                            el_release(r_then)
+                            // check for {#else} — lexed as LBrace Else RBrace
+                            let else_children: [Map<String, Any>] = native_list_empty()
+                            let ck = tok_kind(tokens, p)
+                            if str_eq(ck, "LBrace") {
+                                let ck2 = tok_kind(tokens, p + 1)
+                                if str_eq(ck2, "Else") {
+                                    // consume { else }
+                                    let p = p + 2
+                                    let p = expect(tokens, p, "RBrace")
+                                    // parse else-children until {/if}
+                                    let r_else = parse_html_children(tokens, p, "__if_else__")
+                                    let else_children = r_else["children"]
+                                    let p = r_else["pos"]
+                                    el_release(r_else)
                                 }
                             }
-                            if is_raw_call {
-                                let raw_args = interp_val["args"]
-                                let raw_inner = native_list_get(raw_args, 0)
-                                let children = native_list_append(children, { "html": "Raw", "value": raw_inner })
+                            let if_node: Map<String, Any> = { "html": "HtmlIf", "cond": cond_expr, "then": then_children, "else": else_children }
+                            let children = native_list_append(children, if_node)
+                        } else {
+                            if str_eq(k2, "Else") {
+                                // {#else} sentinel — lexed as LBrace Else RBrace
+                                // Do NOT consume — leave position for caller ({#if} handler checks for it)
+                                let running = false
                             } else {
-                                let children = native_list_append(children, { "html": "Interp", "value": interp_val })
+                                // Check for {#each list as item} — lexed as LBrace Ident:"each" ...
+                                let k2_v = tok_value(tokens, p + 1)
+                                if str_eq(k2_v, "each") {
+                                    let p = p + 2
+                                    // parse list expr up to "as" keyword
+                                    let prev_no_block: String = state_get("__no_block_expr")
+                                    state_set("__no_block_expr", "1")
+                                    let r_list = parse_expr(tokens, p)
+                                    state_set("__no_block_expr", prev_no_block)
+                                    let list_expr = r_list["node"]
+                                    let p = r_list["pos"]
+                                    // r_list result map fully consumed — release to free peak heap.
+                                    el_release(r_list)
+                                    // expect "as"
+                                    let p = expect(tokens, p, "As")
+                                    // item variable name
+                                    let item_name = tok_value(tokens, p)
+                                    let p = p + 1
+                                    // consume closing }
+                                    let p = expect(tokens, p, "RBrace")
+                                    // parse body until {/each}
+                                    let r_body = parse_html_each_body(tokens, p)
+                                    let body_children = r_body["children"]
+                                    let p = r_body["pos"]
+                                    // r_body result map fully consumed — release to free peak heap.
+                                    el_release(r_body)
+                                    let each_node: Map<String, Any> = { "html": "Each", "list": list_expr, "item": item_name, "body": body_children }
+                                    let children = native_list_append(children, each_node)
+                                } else {
+                                    // regular {expr} — disable map-literal parsing so {fn(a,b)}
+                                    // does not trigger the LBrace→map path inside parse_primary
+                                    let prev_no_block: String = state_get("__no_block_expr")
+                                    state_set("__no_block_expr", "1")
+                                    let r = parse_expr(tokens, p + 1)
+                                    state_set("__no_block_expr", prev_no_block)
+                                    let interp_val = r["node"]
+                                    let p = r["pos"]
+                                    // r result map fully consumed — release to free peak heap.
+                                    el_release(r)
+                                    let p = expect(tokens, p, "RBrace")
+                                    // Check if the expr is a call to raw()
+                                    let is_raw_call = false
+                                    let interp_kind: String = interp_val["expr"]
+                                    if str_eq(interp_kind, "Call") {
+                                        let fn_node = interp_val["func"]
+                                        let fn_kind: String = fn_node["expr"]
+                                        if str_eq(fn_kind, "Ident") {
+                                            let fn_name_v: String = fn_node["name"]
+                                            if str_eq(fn_name_v, "raw") {
+                                                let is_raw_call = true
+                                            }
+                                        }
+                                    }
+                                    if is_raw_call {
+                                        let raw_args = interp_val["args"]
+                                        let raw_inner = native_list_get(raw_args, 0)
+                                        let children = native_list_append(children, { "html": "Raw", "value": raw_inner })
+                                    } else {
+                                        let children = native_list_append(children, { "html": "Interp", "value": interp_val })
+                                    }
+                                }
                             }
                         }
                     }
@@ -565,6 +655,27 @@ fn parse_html_element(tokens: [Any], pos: Int) -> Map<String, Any> {
     if is_void_element(tag_name) {
         return make_result({ "html": "Element", "tag": tag_name, "attrs": attrs, "children": native_list_empty(), "self_closing": true }, p)
     }
+    // raw-text mode for style/script — collect content as plain text without parsing CSS/JS as El
+    if str_eq(tag_name, "style") {
+        let r_raw = parse_raw_text_content(tokens, p, "style")
+        let raw_text: String = r_raw["text"]
+        let p = r_raw["pos"]
+        el_release(r_raw)
+        let raw_child: Map<String, Any> = { "html": "Text", "text": raw_text }
+        let raw_children: [Map<String, Any>] = native_list_empty()
+        let raw_children = native_list_append(raw_children, raw_child)
+        return make_result({ "html": "Element", "tag": tag_name, "attrs": attrs, "children": raw_children, "self_closing": false }, p)
+    }
+    if str_eq(tag_name, "script") {
+        let r_raw = parse_raw_text_content(tokens, p, "script")
+        let raw_text: String = r_raw["text"]
+        let p = r_raw["pos"]
+        el_release(r_raw)
+        let raw_child: Map<String, Any> = { "html": "Text", "text": raw_text }
+        let raw_children: [Map<String, Any>] = native_list_empty()
+        let raw_children = native_list_append(raw_children, raw_child)
+        return make_result({ "html": "Element", "tag": tag_name, "attrs": attrs, "children": raw_children, "self_closing": false }, p)
+    }
     // parse children
     let r_children = parse_html_children(tokens, p, tag_name)
     let children = r_children["children"]
@@ -718,44 +829,123 @@ fn parse_primary(tokens: [Any], pos: Int) -> Map<String, Any> {
             // as the start of the block they're expecting.
             return make_result({ "expr": "Nil" }, pos)
         }
-        let p = pos + 1
-        let pairs: [Map<String, Any>] = native_list_empty()
-        let running = true
-        while running {
-            let k2 = tok_kind(tokens, p)
-            if k2 == "RBrace" {
-                let running = false
-            } else {
-                if k2 == "Eof" {
+        // Distinguish map literal from interpolation chain.
+        // A map literal requires { key: value } — the second token inside { must be Colon.
+        // An empty {} is a map literal.  Everything else is an interpolation chain.
+        let first_k: String = tok_kind(tokens, pos + 1)
+        let second_k: String = tok_kind(tokens, pos + 2)
+        if str_eq(first_k, "RBrace") {
+            // Empty map literal {}
+            return make_result({ "expr": "Map", "pairs": native_list_empty() }, pos + 2)
+        }
+        if str_eq(second_k, "Colon") {
+            // MAP LITERAL: { key: value, ... }
+            let p = pos + 1
+            let pairs: [Map<String, Any>] = native_list_empty()
+            let running = true
+            while running {
+                let k2 = tok_kind(tokens, p)
+                if k2 == "RBrace" {
                     let running = false
                 } else {
-                    // key: Str token
-                    let key = tok_value(tokens, p)
-                    let new_p: Int = p + 1
-                    let new_p = expect(tokens, new_p, "Colon")
-                    let r = parse_expr(tokens, new_p)
-                    let val_node = r["node"]
-                    let new_p = r["pos"]
-                    // r result map fully consumed — release to free peak heap.
-                    el_release(r)
-                    let pair = { "key": key, "value": val_node }
-                    let pairs = native_list_append(pairs, pair)
-                    let k3 = tok_kind(tokens, new_p)
-                    if k3 == "Comma" {
-                        let new_p = new_p + 1
-                    }
-                    // Non-progress guard: malformed map content can leave
-                    // parse_expr returning the same pos. Force advance.
-                    if new_p <= p {
-                        let p = p + 1
+                    if k2 == "Eof" {
+                        let running = false
                     } else {
-                        let p = new_p
+                        // key: Str or Ident token
+                        let key = tok_value(tokens, p)
+                        let new_p: Int = p + 1
+                        let new_p = expect(tokens, new_p, "Colon")
+                        let r = parse_expr(tokens, new_p)
+                        let val_node = r["node"]
+                        let new_p = r["pos"]
+                        // r result map fully consumed — release to free peak heap.
+                        el_release(r)
+                        let pair = { "key": key, "value": val_node }
+                        let pairs = native_list_append(pairs, pair)
+                        let k3 = tok_kind(tokens, new_p)
+                        if k3 == "Comma" {
+                            let new_p = new_p + 1
+                        }
+                        // Non-progress guard: malformed map content can leave
+                        // parse_expr returning the same pos. Force advance.
+                        if new_p <= p {
+                            let p = p + 1
+                        } else {
+                            let p = new_p
+                        }
                     }
                 }
             }
+            let p = expect(tokens, p, "RBrace")
+            return make_result({ "expr": "Map", "pairs": pairs }, p)
         }
-        let p = expect(tokens, p, "RBrace")
-        return make_result({ "expr": "Map", "pairs": pairs }, p)
+        // INTERPOLATION CHAIN: {expr}, {expr}{expr}, {expr}<html>, etc.
+        // Build a BinOp(Plus, ...) concatenation chain.
+        let p = pos
+        let chain_node: Map<String, Any> = { "expr": "Nil" }
+        let chain_started = false
+        let chain_running = true
+        while chain_running {
+            let ck: String = tok_kind(tokens, p)
+            if str_eq(ck, "LBrace") {
+                let prev_no_block: String = state_get("__no_block_expr")
+                state_set("__no_block_expr", "1")
+                let r = parse_expr(tokens, p + 1)
+                state_set("__no_block_expr", prev_no_block)
+                let part = r["node"]
+                let p = r["pos"]
+                // r result map fully consumed — release to free peak heap.
+                el_release(r)
+                let p = expect(tokens, p, "RBrace")
+                if !chain_started {
+                    let chain_node = part
+                    let chain_started = true
+                } else {
+                    let chain_node: Map<String, Any> = { "expr": "BinOp", "op": "Plus", "left": chain_node, "right": part }
+                }
+            } else {
+                if str_eq(ck, "Lt") {
+                    let ck2: String = tok_kind(tokens, p + 1)
+                    if str_eq(ck2, "Not") {
+                        let r = parse_html_template(tokens, p)
+                        let part = r["node"]
+                        let p = r["pos"]
+                        // r result map fully consumed — release to free peak heap.
+                        el_release(r)
+                        if !chain_started {
+                            let chain_node = part
+                            let chain_started = true
+                        } else {
+                            let chain_node: Map<String, Any> = { "expr": "BinOp", "op": "Plus", "left": chain_node, "right": part }
+                        }
+                    } else {
+                        if str_eq(ck2, "Ident") {
+                            let tag_candidate: String = tok_value(tokens, p + 1)
+                            if is_html_tag_name(tag_candidate) {
+                                let r = parse_html_template(tokens, p)
+                                let part = r["node"]
+                                let p = r["pos"]
+                                // r result map fully consumed — release to free peak heap.
+                                el_release(r)
+                                if !chain_started {
+                                    let chain_node = part
+                                    let chain_started = true
+                                } else {
+                                    let chain_node: Map<String, Any> = { "expr": "BinOp", "op": "Plus", "left": chain_node, "right": part }
+                                }
+                            } else {
+                                let chain_running = false
+                            }
+                        } else {
+                            let chain_running = false
+                        }
+                    }
+                } else {
+                    let chain_running = false
+                }
+            }
+        }
+        return make_result(chain_node, p)
     }
 
     // if expression
@@ -1875,6 +2065,219 @@ fn skip_expr_to_stmt_boundary(tokens: [Any], pos: Int) -> Int {
     p
 }
 
+// scan_type_el — read a type annotation starting at pos and return its El
+// source representation as a string, plus the new position.
+// Returns { "el": String, "pos": Int }.
+// Handles: Ident, [Type], Map<K,V>, Type?, Type<T,...> (same shapes as skip_type).
+fn scan_type_el(tokens: [Any], pos: Int) -> Map<String, Any> {
+    let k: String = tok_kind(tokens, pos)
+    // Array type: [Type]
+    if str_eq(k, "LBracket") {
+        let p: Int = pos + 1
+        let inner = scan_type_el(tokens, p)
+        let inner_str: String = inner["el"]
+        let p = inner["pos"]
+        el_release(inner)
+        let p = expect(tokens, p, "RBracket")
+        return { "el": "[" + inner_str + "]", "pos": p }
+    }
+    // Named type (possibly generic or optional)
+    if str_eq(k, "Ident") {
+        let name: String = tok_value(tokens, pos)
+        let p: Int = pos + 1
+        let k2: String = tok_kind(tokens, p)
+        if str_eq(k2, "Lt") {
+            // Generic params: collect until matching >
+            let p = p + 1
+            let depth: Int = 1
+            let parts: [String] = native_list_empty()
+            let parts = native_list_append(parts, name + "<")
+            let running: Bool = true
+            while running {
+                let kk: String = tok_kind(tokens, p)
+                if str_eq(kk, "Eof") {
+                    let running = false
+                } else {
+                    if str_eq(kk, "Lt") {
+                        let depth = depth + 1
+                        let parts = native_list_append(parts, "<")
+                        let p = p + 1
+                    } else {
+                        if str_eq(kk, "Gt") {
+                            let depth = depth - 1
+                            let p = p + 1
+                            if depth <= 0 {
+                                let parts = native_list_append(parts, ">")
+                                let running = false
+                            } else {
+                                let parts = native_list_append(parts, ">")
+                            }
+                        } else {
+                            if str_eq(kk, "Comma") {
+                                let parts = native_list_append(parts, ", ")
+                                let p = p + 1
+                            } else {
+                                let parts = native_list_append(parts, tok_value(tokens, p))
+                                let p = p + 1
+                            }
+                        }
+                    }
+                }
+            }
+            let k3: String = tok_kind(tokens, p)
+            if str_eq(k3, "QuestionMark") { let p = p + 1 }
+            let result: String = str_join(parts, "")
+            el_release(parts)
+            return { "el": result, "pos": p }
+        }
+        // Optional marker
+        if str_eq(k2, "QuestionMark") {
+            return { "el": name + "?", "pos": p + 1 }
+        }
+        return { "el": name, "pos": p }
+    }
+    // Fallback: unknown token, treat as Any
+    { "el": "Any", "pos": pos + 1 }
+}
+
+// scan_params_el — scan a parameter list `(name: Type, ...)` starting at
+// position `pos` (which should point at LParen) and return the El parameter
+// declaration string (e.g. "a: String, b: Int") along with the new position.
+// Returns { "el": String, "pos": Int }.
+// Used by scan_fn_sigs_el for --emit-header without building full AST.
+fn scan_params_el(tokens: [Any], pos: Int) -> Map<String, Any> {
+    let p: Int = expect(tokens, pos, "LParen")
+    let parts: [String] = native_list_empty()
+    let going: Bool = true
+    while going {
+        let kk: String = tok_kind(tokens, p)
+        if str_eq(kk, "RParen") {
+            let going = false
+        } else {
+            if str_eq(kk, "Eof") {
+                let going = false
+            } else {
+                let pname: String = tok_value(tokens, p)
+                let p = p + 1
+                let p = expect(tokens, p, "Colon")
+                let tr = scan_type_el(tokens, p)
+                let ptype: String = tr["el"]
+                let p = tr["pos"]
+                el_release(tr)
+                let parts = native_list_append(parts, pname + ": " + ptype)
+                let k2: String = tok_kind(tokens, p)
+                if str_eq(k2, "Comma") {
+                    let p = p + 1
+                }
+            }
+        }
+    }
+    let p = expect(tokens, p, "RParen")
+    let el_str: String = str_join(parts, ", ")
+    el_release(parts)
+    { "el": el_str, "pos": p }
+}
+
+// scan_fn_sigs_el — lightweight token-level pre-scan for --emit-header.
+//
+// Like scan_fn_sigs but captures El-style type strings instead of C types.
+// Only records fn/extern_fn entries (header generation ignores lets/blocks).
+//
+// Descriptor shape:
+//   { "kind": "fn"|"extern_fn", "name": String,
+//     "params_el": String,   <- El param list, e.g. "a: String, b: Int"
+//     "ret_el": String }     <- El return type, e.g. "String" or "Void"
+//
+// Peak memory: O(tokens) with no expression AST allocation.
+fn scan_fn_sigs_el(tokens: [Any]) -> [Map<String, Any>] {
+    let total: Int = native_list_len(tokens) / 2
+    let sigs: [Map<String, Any>] = native_list_empty()
+    let pos: Int = 0
+    let going: Bool = true
+    while going {
+        if pos >= total {
+            let going = false
+        } else {
+            let k: String = tok_kind(tokens, pos)
+            if str_eq(k, "Eof") {
+                let going = false
+            } else {
+                // --- fn definition ---
+                if str_eq(k, "Fn") {
+                    let p: Int = pos + 1
+                    let name: String = tok_value(tokens, p)
+                    let p = p + 1
+                    let pr = scan_params_el(tokens, p)
+                    let params_el: String = pr["el"]
+                    let p = pr["pos"]
+                    el_release(pr)
+                    // read return type
+                    let ret_el: String = "Any"
+                    let k2: String = tok_kind(tokens, p)
+                    if str_eq(k2, "Arrow") {
+                        let p = p + 1
+                        let tr = scan_type_el(tokens, p)
+                        let ret_el = tr["el"]
+                        let p = tr["pos"]
+                        el_release(tr)
+                    }
+                    // skip body
+                    let k3: String = tok_kind(tokens, p)
+                    if str_eq(k3, "LBrace") {
+                        let p = skip_to_rbrace(tokens, p)
+                    }
+                    if !str_eq(name, "main") {
+                        let sigs = native_list_append(sigs, {
+                            "kind": "fn",
+                            "name": name,
+                            "params_el": params_el,
+                            "ret_el": ret_el
+                        })
+                    }
+                    let pos = p
+                } else {
+                // --- extern fn ---
+                if str_eq(k, "Extern") {
+                    let p: Int = pos + 1
+                    let k2: String = tok_kind(tokens, p)
+                    if str_eq(k2, "Fn") {
+                        let p = p + 1
+                        let name: String = tok_value(tokens, p)
+                        let p = p + 1
+                        let pr = scan_params_el(tokens, p)
+                        let params_el: String = pr["el"]
+                        let p = pr["pos"]
+                        el_release(pr)
+                        let ret_el: String = "Any"
+                        let k3: String = tok_kind(tokens, p)
+                        if str_eq(k3, "Arrow") {
+                            let p = p + 1
+                            let tr = scan_type_el(tokens, p)
+                            let ret_el = tr["el"]
+                            let p = tr["pos"]
+                            el_release(tr)
+                        }
+                        let sigs = native_list_append(sigs, {
+                            "kind": "extern_fn",
+                            "name": name,
+                            "params_el": params_el,
+                            "ret_el": ret_el
+                        })
+                        let pos = p
+                    } else {
+                        let pos = pos + 1
+                    }
+                } else {
+                    // Let, Cgi, Service, Import, Type, Enum, From — skip to boundary.
+                    let p: Int = pos + 1
+                    let p = skip_expr_to_stmt_boundary(tokens, p)
+                    let pos = p
+                }}}
+            }
+        }
+    sigs
+}
+
 // scan_params_c — scan a parameter list `(name: Type, ...)` starting at
 // position `pos` (which should point at LParen) and return the C parameter
 // declaration string along with the new position.