Add an nodejs engine which reads a file and process searching.

Author: hzhangxyz

examples/engine.ds

@@ -0,0 +1,12 @@
+(`P -> `Q)
+`P
+----------
+`Q
+
+(`p -> (`q -> `p))
+
+((`p -> (`q -> `r)) -> ((`p -> `q) -> (`p -> `r)))
+
+(((! `p) -> (! `q)) -> (`q -> `p))
+
+(! (! X))

examples/engine.mjs

@@ -0,0 +1,112 @@
+/* jshint esversion:8 */
+
+import {
+    readFile,
+} from "node:fs/promises";
+import {
+    argv,
+    stdin,
+    stdout,
+    exit,
+} from "node:process";
+import {
+    createInterface
+} from "node:readline/promises";
+import {
+    buffer_size,
+    rule_t,
+}
+from "../jsds/jsds.mjs";
+
+function* search(input_strings) {
+    buffer_size(1000);
+
+    let rules = {};
+    let facts = {};
+
+    let cycle = -1;
+
+    for (let input_string of input_strings) {
+        let rule = new rule_t(input_string);
+        if (rule.length() !== 0) {
+            rules[rule.key()] = [rule, cycle];
+        } else {
+            facts[rule.key()] = [rule, cycle];
+        }
+    }
+
+    while (true) {
+        let temp_rules = {};
+        let temp_facts = {};
+
+        for (let r_hash in rules) {
+            for (const f_hash in facts) {
+                const [rule, r_cycle] = rules[r_hash];
+                const [fact, f_cycle] = facts[f_hash];
+                if (r_cycle !== cycle && f_cycle !== cycle) {
+                    continue;
+                }
+                const candidate = rule.match(fact);
+                if (candidate === null) {
+                    continue;
+                }
+                const candidate_hash = candidate.key();
+                if (candidate.length() !== 0) {
+                    // rule
+                    if (candidate_hash in rules || candidate_hash in temp_rules) {
+                        continue;
+                    }
+                    temp_rules[candidate_hash] = candidate;
+                } else {
+                    // fact
+                    if (candidate_hash in facts || candidate_hash in temp_facts) {
+                        continue;
+                    }
+                    temp_facts[candidate_hash] = candidate;
+                }
+                console.log(candidate.toString());
+            }
+        }
+
+        cycle++;
+        for (let r_hash in temp_rules) {
+            const rule = temp_rules[r_hash];
+            rules[rule.key()] = [rule, cycle];
+        }
+        for (let f_hash in temp_facts) {
+            const fact = temp_facts[f_hash];
+            facts[fact.key()] = [fact, cycle];
+        }
+
+        yield;
+    }
+}
+
+async function read_file_to_string_array(file_path) {
+    const content = await readFile(file_path, "utf-8");
+    const sections = content.split(/\n\n/);
+    const results = sections
+          .filter(section => section.trim().length > 0)
+          .map(section => section.trim());
+    return results;
+}
+
+async function main() {
+    if (argv.length < 3) {
+        console.error("Usage: node engine.mjs <file_path>");
+        exit(1);
+    }
+    const file_path = argv[2];
+    const data = await read_file_to_string_array(file_path);
+    const generator = search(data);
+    const handle = createInterface({
+        input: stdin,
+        output: stdout
+    });
+    while (true) {
+        generator.next();
+        await handle.question("Press Enter to continue...");
+    }
+}
+
+await main(); // jshint ignore:line

rollup.config.mjs

@@ -5,12 +5,13 @@ import terser from "@rollup/plugin-terser";
 export default {
     input: {
         jsds: "jsds/jsds.mjs",
-        example: "examples/main.mjs"
+        example: "examples/main.mjs",
+        engine: "examples/engine.mjs",
     },
     output: [{
         dir: "dist",
         format: "es",
-        entryFileNames: "[name].mjs"
+        entryFileNames: "[name].mjs",
     }],
-    plugins: [terser()]
+    plugins: [terser()],
 };