Fix about page

prism-compiler/README.md

@@ -5,56 +5,6 @@
 
 ## About
 
-This crate provides a PEG parser with the following features:
-* Support for left recursion
-* Adaptation: The grammar can be changed dynamically during parsing
+Prism is a dependently typed programming language with an adaptive grammar.
 
 This crate is under heavy development and not yet ready to be used in production code.
-
-
-## Example
-This defines the grammar of a simple arithmetic language, and support to adapt the language: 
-```
-rule start = block;
-rule block {
-    b <- "grammar" "{" g:grammar(prule_action) "}" ";" b:#adapt(g, block);
-    s :: b <- s:stmt ";" b:block;
-    [] <- "";
-}
-
-rule stmt {
-    Let(e) <- "let" e:expr;
-    Do() <- "do";
-}
-
-rule expr {
-    group additive {
-        Add(x, y) <- x:#next "+" y:#this;
-    }
-    group multiplicative {
-        Mul(x, y) <- x:#next "*" y:#this;
-    }
-    group base {
-        Block(b) <- "(" b:block ")";
-        UnaryMinus(v) <- "-" v:#this;
-        Num(n) <- n:#str([0-9]*);
-    }
-}
-
-rule layout = [' ' | '\n'];
-```
-
-Example programs in this language:
-```
-1 * 2 + -3
-```
-```
-grammar {
-    rule expr {
-        group additive {
-            1 + (-2) <- x:#next "-" y:#this;
-        }
-    }
-};
-1 - 2
-```