Predefine commonly used combinators

codedot · codedot · commit 3b7e90de3477 · 2017-01-22T21:11:16.000+02:00
diff --git a/Makefile b/Makefile
@@ -1,7 +1,7 @@
 all: compile.js
 	npm install
 	node lambda -h
-	node lambda -e "(x, y, z: x z (y z)) hello bye world"
+	node lambda -ce "S hello bye world"
 	node lambda -d debug.mlc
 	node lambda -pt fact.mlc
 
diff --git a/README.md b/README.md
@@ -9,6 +9,7 @@ This package provides a `lambda` command with the following interface:
 Usage: lambda [options] (<file> | -e <expr>)
 
 Options:
+  --comb, -c     Predefine commonly used combinators         [boolean]
   --term, -t     Output the term being evaluated             [boolean]
   --perf, -p     Print benchmarks                            [boolean]
   --expr, -e     Process the argument as expression          [boolean]
diff --git a/helper.txt b/helper.txt
@@ -0,0 +1,28 @@
+I = x: x;
+K = x, y: x;
+S = x, y, z: x z (y z);
+T = K;
+F = x, y: y;
+AND = p, q: p q F;
+OR = p, q: p T q;
+NOT = p: (a, b: p b a);
+C0 = f, x: x;
+C1 = f, x: f x;
+C2 = f, x: f (f x);
+C3 = f, x: f (f (f x));
+C4 = f, x: f (f (f (f x)));
+C5 = f, x: f (f (f (f (f x))));
+C6 = f, x: f (f (f (f (f (f x)))));
+C7 = f, x: f (f (f (f (f (f (f x))))));
+C8 = f, x: f (f (f (f (f (f (f (f x)))))));
+C9 = f, x: f (f (f (f (f (f (f (f (f x))))))));
+C10 = f, x: f (f (f (f (f (f (f (f (f (f x)))))))));
+SUCC = n: (f, x: f (n f x));
+PLUS = m, n: (f, x: m f (n f x));
+MULT = m, n: (f: m (n f));
+EXP = m, n: n m;
+PRED = n: (f, x: n (g, h: h (g f)) (K x) I);
+MINUS = m, n: n PRED m;
+ZERO = n: n (K F) T;
+A = self, f: f (self self f);
+Y = A A;
diff --git a/lambda.js b/lambda.js
@@ -2,9 +2,15 @@
 
 var lambda = require(".");
 var yargs = require("yargs");
+var path = require("path");
 var fs = require("fs");
 
 var opts = {
+	comb: {
+		alias: "c",
+		desc: "Predefine commonly used combinators",
+		boolean: true
+	},
 	term: {
 		alias: "t",
 		desc: "Output the term being evaluated",
@@ -44,18 +50,22 @@ var argv = yargs
 	.wrap(70)
 	.argv;
 
+var comb = fs.readFileSync(path.join(__dirname, "helper.txt"), "utf8");
 var input = argv._[0];
 
 if (!argv.expr)
 	input = fs.readFileSync(input, "utf8");
 
+if (argv.comb)
+	input = comb.concat(input);
+
 if (argv.debug) {
 	var eqn;
 
 	lambda.prepare(input);
 
 	while (eqn = lambda.debug1())
-		console.log(eqn);
+		console.info(eqn);
 } else {
 	var output = lambda(input);
 	var stats = JSON.stringify(output.stats, null, "\t");
