A REPL's language is named and found as the syntax table finds one: aliases, any case

Repl took only the grammar's exact name, and a file's language was found by a case-sensitive suffix of its path, apart from the aliases a code fence already had. The aliases move to grammar_manifest with byName and byPath, which syntax, Repl and langOf share, so `Repl py` and a .PY file work. The line-by-line warning is for the python language, not an id that starts with python. Joincol's doc line was sitting on Repl.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 6 insertions, 5 deletions

diff --git a/src/builtins.zig b/src/builtins.zig
index ed42dfe3..79c45325 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -903,7 +903,6 @@ pub const Tty9p = struct {
 };
 
 /// Fold the active pane's column into the one on its right, keeping its panes.
-/// The horizontal mirror of the vertical stacking `New` does.
 /// Binds this terminal as a language's REPL, by the language's name as the
 /// syntax table has it: an exec made on the body of a file in that
 /// language -- a middle click, the execute key, a single word like `ls`
@@ -934,10 +933,11 @@ pub const Repl = struct {
             pane.repl = null;
             return c.p.setMessage(c.id, "Repl: unbound");
         }
-        const grammars = @import("grammar_manifest.zig").all;
-        const lang: u8 = for (grammars, 0..) |g, i| {
-            if (g.exts.len > 0 and std.mem.eql(u8, g.name, arg)) break @intCast(i);
-        } else {
+        const manifest = @import("grammar_manifest.zig");
+        const grammars = manifest.all;
+        // Named as a code fence names it: `py`, `Python`, `sh`.
+        const named: ?u8 = if (manifest.byName(arg)) |i| if (grammars[i].exts.len > 0) @intCast(i) else null else null;
+        const lang: u8 = named orelse {
             var w = std.Io.Writer.fixed(&buf);
             w.print("Repl: no language \"{s}\"; one of", .{arg[0..@min(arg.len, 32)]}) catch {};
             for (grammars) |g| if (g.exts.len > 0) w.print(" {s}", .{g.name}) catch break;
@@ -962,6 +962,7 @@ pub const Repl = struct {
     }
 };
 
+/// The horizontal mirror of the vertical stacking `New` does.
 pub const Joincol = struct {
     pub const scope: Scope = .session;
     pub fn run(c: Ctx) void {