ludic/packages/ludic.ui/eval.ludic
Orkuncakilkaya 20d011f8e9 feat(lang): UI components as files - component Name { ... } beside Name.xml and Name.lss
The compiler turns a component declaration into:
- a record of its props and state;
- a constructor, a props setter, a model and a call;
- a class, registered with ludic.ui at start.

Its template and styles are read from beside it and compiled in, with @import inlined, and a
missing template fails the build.

In the runtime:
- each mounted instance keeps its own props and state, and `set` in a template writes the state;
- styles are scoped to the component;
- class, style and id on a component's tag land on its root, styled by the parent's sheet too;
- ui_reload re-reads a component's files from disk and keeps instances.

The package's own module is now ludic_ui, so a program may call a directory of its own ui.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-24 16:50:12 +03:00

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# eval.ludic - an expression's value, here
function ui_eval(x: UiExpr, e: UiEnv) -> Val {
if x.op == X_LIT { return x.v }
if x.op == X_NAME { return env_get(e, x.s) }
if x.op == X_MEMBER {
let o = ui_eval(x.a, e)
if Value.kind(o) == 6 and Value.has(o, x.s) != 0 { return Value.get(o, x.s) }
if Value.kind(o) == 5 and x.s == "length" { return Value.int(Value.count(o)) }
ui_err(`.{x.s}: there is no such field`)
return Value.null()
}
if x.op == X_INDEX { return Value.at(ui_eval(x.a, e), Value.as_int(ui_eval(x.b, e))) }
if x.op == X_CALL { return ev_call(x, e) }
if x.op == X_NOT { return vl_bool(not vl_truthy(ui_eval(x.a, e))) }
if x.op == X_NEG { return vl_arith("-", Value.int(0), ui_eval(x.a, e)) }
if x.op == X_AND {
if not vl_truthy(ui_eval(x.a, e)) { return vl_bool(false) }
return vl_bool(vl_truthy(ui_eval(x.b, e)))
}
if x.op == X_OR {
if vl_truthy(ui_eval(x.a, e)) { return vl_bool(true) }
return vl_bool(vl_truthy(ui_eval(x.b, e)))
}
if x.op == X_COND {
if vl_truthy(ui_eval(x.a, e)) { return ui_eval(x.b, e) }
return ui_eval(x.c, e)
}
if x.op == X_TEXT {
var out = ""
for i in 0 .. len(x.args) { out = out + vl_text(ui_eval(x.args[i], e)) }
return Value.str(out)
}
return vl_binary(x.s, ui_eval(x.a, e), ui_eval(x.b, e))
}
# a call: len() and range() are the template's own, anything else is the view's
function ev_call(x: UiExpr, e: UiEnv) -> Val {
let args = Value.list()
for i in 0 .. len(x.args) { Value.add(args, ui_eval(x.args[i], e)) }
if x.s == "len" and len(x.args) == 1 { return Value.int(Value.count(Value.at(args, 0))) }
if x.s == "range" and len(x.args) == 1 {
let out = Value.list()
for i in 0 .. Value.as_int(Value.at(args, 0)) { Value.add(out, Value.int(i)) }
return out
}
var at = e
while at != null {
if at.inst != null {
let r = at.inst.cls.call(at.inst.ptr, x.s, args)
if Value.kind(r) != 99 { return r }
}
at = at.parent
}
if ui_view == null or ui_view.call == null {
ui_err(`{x.s}(): there is no function or event of that name here`)
return Value.null()
}
return ui_view.call(x.s, args)
}
function ui_eval_text(x: UiExpr, e: UiEnv) -> string { return vl_text(ui_eval(x, e)) }
function ui_eval_bool(x: UiExpr, e: UiEnv) -> bool { return vl_truthy(ui_eval(x, e)) }