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forestbelton / solver.html
Last active July 8, 2016 05:00
dfs "sliding on ice" puzzle solver
<!DOCTYPE html>
<html>
<head>
<style>
#grid {
line-height: 0;
}
#grid > * {
margin:0;
@forestbelton
forestbelton / data.g
Last active November 24, 2015 19:53
data declaration peg parser
Decl "data declaration"
= Data name:TName params:TParam* Equals first:Constructor rest:Alternative* {
return {
name: name,
params: params,
constructors: [first].concat(rest)
};
}
Data "data keyword"
@forestbelton
forestbelton / gist:8dd3414a81e2fca9ca53
Last active August 29, 2015 14:23 — forked from StoneCypher/gist:374acd81c3ca00393297
start
= (d:die _ { return d })*
number
= [0-9]
nonzero
= [1-9]
diesize
@forestbelton
forestbelton / my_log.c
Last active August 29, 2015 14:04
quick logarithm
#include <math.h>
double my_log(double x) {
static const double log2 = 0.693147;
double y, logy;
int n;
// factor x = y * 2^n, where 1 <= y < 2
// frexp gives us the range 0.5 <= y < 1
@forestbelton
forestbelton / gist:b9f40a91f4f18510e317
Last active August 29, 2015 14:01
lazy evaluation with sweet.js
macro lazy {
rule { $e:expr } => {
new function() {
this.done = false;
this.valueOf = function() {
if(!this.done) {
this.done = true;
this.value = $e;
}
return this.value;
@forestbelton
forestbelton / rm_lr.js
Created February 19, 2014 06:05
remove left recursion
var rm_lr = function(name, grammar) {
var p_with = grammar[name].filter(function(x) { return x[0] == name; }),
p_wo = grammar[name].filter(function(x) { return x[0] != name; });
grammar[name] = p_wo.concat(p_wo.map(function(wo) {
return wo.concat([name + "'"]);
}));
grammar[name + "'"] = [['e']].concat(p_with.map(function(x) {
return x.slice(1).concat([name + "'"]);
@forestbelton
forestbelton / lambda.js
Created February 12, 2014 20:42
curried lambdas with sweet.js
macro lam {
rule { $x:ident $y:expr -> $body:expr } => {
(function($x) { return lam $y -> $body; })
}
rule { $x:ident -> $body:expr } => {
(function($x) { return $body; })
}
}
@forestbelton
forestbelton / zipr.erl
Last active December 25, 2015 13:59
everyday zipper type
-module(zipr).
-export([new/1, cur/1, to_list/1, next/1, prev/1, addl/2, addr/2]).
new(X) -> {[], X, []}.
cur({_L, X, _R}) -> X.
to_list({L, X, R}) -> lists:reverse(L) ++ [X] ++ R.
next({L, X, [H|R]}) -> {[X]++L, H, R}.
prev({[H|L], X, R}) -> {L, X, [H]++R}.
addl({L, X, R}, X1) -> {L, X1, [X]++R}.
addr({L, X, R}, X1) -> {[X]++L, X1, R}.
@forestbelton
forestbelton / leqn.hs
Last active December 16, 2015 04:29
slightly better equation solver with support for conditionals, expression parsing, and pretty-printing. unfortunately very ugly
{-# LANGUAGE DeriveFunctor #-}
import Text.ParserCombinators.Parsec
import Data.Functor.Foldable
import qualified Data.Set as S
data FormF a = Var Char
| Not a
| And a a
| Or a a
@forestbelton
forestbelton / vvtb.coffee
Created April 6, 2013 04:46
VVTB interpreter
intro = [
'=======================================',
'VVTB (Very Very Tiny Basic) interpreter',
'(c) 2012 Forest Belton (case)',
'======================================='
]
prgm = {}
vars = {}