4263

Implement literal constants before type abbreviations, reducing some
unnecessary tangling.

1 files changed, 63 insertions, 0 deletions

diff --git a/018constant.cc b/018constant.cc
new file mode 100644
index 00000000..97239bbe
--- /dev/null
+++ b/018constant.cc
@@ -0,0 +1,63 @@
+//: A few literal constants.
+
+:(scenarios load)  // use 'load' instead of 'run' in all scenarios in this layer
+
+:(before "End Mu Types Initialization")
+put(Type_ordinal, "literal-boolean", 0);
+
+//: 'true'
+
+:(scenario true)
+def main [
+  1:boolean <- copy true
+]
++parse:   ingredient: {true: "literal-boolean"}
+
+:(before "End Parsing reagent")
+if (name == "true") {
+  if (type != NULL) {
+    raise << "'true' is a literal and can't take a type\n" << end();
+    return;
+  }
+  type = new type_tree("literal-boolean");
+  set_value(1);
+}
+
+//: 'false'
+
+:(scenario false)
+def main [
+  1:boolean <- copy false
+]
++parse:   ingredient: {false: "literal-boolean"}
+
+:(before "End Parsing reagent")
+if (name == "false") {
+  if (type != NULL) {
+    raise << "'false' is a literal and can't take a type\n" << end();
+    return;
+  }
+  type = new type_tree("literal-boolean");
+  set_value(0);
+}
+
+//: 'null'
+
+:(before "End Mu Types Initialization")
+put(Type_ordinal, "literal-address", 0);
+
+:(scenario null)
+def main [
+  1:address:number <- copy null
+]
++parse:   ingredient: {null: "literal-address"}
+
+:(before "End Parsing reagent")
+if (name == "null") {
+  if (type != NULL) {
+    raise << "'null' is a literal and can't take a type\n" << end();
+    return;
+  }
+  type = new type_tree("literal-address");
+  set_value(0);
+}