RockstarLang · Prime541 · Jul 7, 2022 · Jul 7, 2022 · Jul 8, 2022
diff --git a/satriani/README.md b/satriani/README.md
@@ -5,9 +5,12 @@ Satriani is a JavaScript interpreter for the Rockstar programming language. Satr
 ## Usage
 
 To run Satriani using nodeJS from the command line:
-```
+```bash
 git clone https://github.com/RockstarLang/rockstar 
 cd rockstar/satriani
+# If yarn is not available:
+#     npm install yarn
+#     node_modules/yarn/bin/yarn install
 yarn install
 yarn pegjs
 node rockstar <program>.rock
@@ -58,7 +61,7 @@ you can use in web pages:
 <html>
 <body>
 
-<script type="text/javascript" src="js/satriani.standalone.js"></script>
+<script type="text/javascript" src="satriani.standalone.js"></script>
 <script type="text/javascript">
     let source = 'Shout "Hello World"';
     let output = console.log;

diff --git a/satriani/rockstar.js b/satriani/rockstar.js
@@ -13,7 +13,7 @@ function execute() {
             let tree = rockstar.parse(data);
             let input = readlineSync.question;
             let output = console.log;
-            let result = rockstar.run(tree, input, output)
+            let result = rockstar.run(tree, input, output, sourceFilePath);
             console.log(result ? result : "(program returned no output)");
         } catch (e) {
             if (e.location && e.location.start) {

diff --git a/satriani/rockstar.peg b/satriani/rockstar.peg
@@ -10,6 +10,8 @@ After updating, run pegjs -o rockstar-parser.js rockstar.peg
   const keywords = new Set([
     // common variable prefixes
     'a', 'an', 'the', 'my', 'your', 'our',
+    // system variable prefix
+    'thy',
 
     // pronouns
     'it', 'he', 'she', 'him', 'her', 'they', 'them', 'ze', 'hir', 'zie', 'zir', 'xe', 'xem', 've', 'ver',
@@ -62,6 +64,15 @@ After updating, run pegjs -o rockstar-parser.js rockstar.peg
     'takes', 'wants',
     'give', 'return', 'send', 'back',
     'taking',
+
+    // imports
+    'give', 'a', 'hand', 'for',
+    'featuring',
+    'welcome', 'to',
+    'quoting',
+    'contains', 'a', 'sample', 'of',
+    'as', 'aka', 'by',
+    'from', 'courtesy', 'of',
   ])
 
   function isKeyword(string) {
@@ -85,7 +96,7 @@ EOF = !.
 
 ignore_rest_of_line = (_[^\n]*)?
 
-statement   = _* s:(break / continue / function / function_call
+statement   = _* s:(break / continue / function / function_call / import
 			/ function_return / loop / conditional / operation / expression) { return s }
 
 break = 'break'i ignore_rest_of_line {
@@ -302,7 +313,7 @@ pronoun = pronoun:(
     ) &(is / _ / EOL / EOF)
     { return { pronoun: pronoun.toLowerCase() } }
 
-common_prefix = ( 'an'i / 'a'i / 'the'i / 'my'i / 'your'i / 'our'i)
+common_prefix = ( 'an'i / 'a'i / 'the'i / 'my'i / 'your'i / 'our'i / 'thy'i )
 
 uppercase_letter = [A-ZÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞĀĂĄĆĈĊČĎĐĒĔĖĘĚĜĞĠĢĤĦĨĪĬĮİĲĴĶĸĹĻĽĿŁŃŅŇŊŌŎŐŒŔŖŘŚŜŞŠŢŤŦŨŪŬŮŰŲŴŶŸŹŻŽ]
 lowercase_letter = [a-zàáâãäåæçèéêëìíîïðñòóôõöøùúûüýþāăąćĉċčďđēĕėęěĝğġģĥħĩīĭįıĳĵķĸĺļľŀłńņňŋōŏőœŕŗřśŝşšţťŧũūŭůűųŵŷÿźżžŉß]
@@ -467,4 +478,41 @@ math_round
   = 'turn'i _ v:variable _ ('round'i/'around'i)
     { return { rounding: { variable: v, direction: 'nearest' } }; }  
   / 'turn'i _ ('round'i/'around'i) _ v:variable
-    { return { rounding: { variable: v, direction: 'nearest' } }; }
+    { return { rounding: { variable: v, direction: 'nearest' } }; }
+
+
+import_aliases = 'Give a hand for'i
+               / 'Featuring'i
+               / 'Welcome to'i
+               / 'Quoting'i
+               / 'Contains a sample of'i
+
+import_as = 'as'i
+          / 'aka'i
+          / 'by'i
+
+import_from = 'from'i
+            / 'of'i
+            / 'courtesy of'i
+
+import
+  = import_aliases _ ul:util_list _ import_from _ f:library
+    { return { import_utils : {utils : ul, library : f} } }
+  / import_aliases _ fl:library_list
+    { return { import_libraries : {libraries : fl} } }
+
+util
+  = u:variable _ import_as _ v:variable
+    { return { name : u, new_name : v } }
+  / u:variable
+    { return { name : u, new_name : u } }
+
+util_list = head:util variable_list_separator tail:util_list
+            { return [head].concat(tail) }
+          / arg:util { return [arg] }
+
+library_list = head:library variable_list_separator tail:library_list
+               { return [head].concat(tail) }
+             / arg:library { return [arg] }
+
+library = v:variable { return { name : v } }
diff --git a/satriani/satriani.interpreter.js b/satriani/satriani.interpreter.js
@@ -1,3 +1,7 @@
+const fs = require('fs');
+const path = require('path');
+const parser = require('./satriani.parser.js');
+
 module.exports = {
     Environment: Environment,
     eq: eq
@@ -50,6 +54,10 @@ Environment.prototype = {
     },
 
     run: function (program) {
+        if (!this.exists("thy_name")) {
+            // This script is not an import; it's executed directly.
+            this.assign("thy_name", "", null, 1);
+        }
         let result = evaluate(program, this);
         return (result ? result.value : undefined);
     },
@@ -209,6 +217,33 @@ function evaluate(tree, env) {
                 return enlist(expr, env);
             case "delist":
                 return delist(expr, env);
+            case "import_utils":
+                // Load library and inject requested symbols in the 'local=1' environment
+                let includeEnv = include(expr.library.name, env);
+                for (i = 0; i < expr.utils.length; ++i) {
+                    let util = expr.utils[i];
+                    if (util.name.startsWith("thy_")) {
+                      throw ("System variables won't be imported: '"+util.name+"'");
+                    }
+                    if (includeEnv.exists(util.name)) {
+                        env.assign(util.new_name, includeEnv.vars[util.name], null, 1);
+                    } else {
+                      throw ("The library '"+expr.library.name+"' does not contain the symbol '"+util.name+"'");
+                    }
+                }
+                return;
+            case "import_libraries":
+                for (i = 0; i < expr.libraries.length; ++i) {
+                    let library = expr.libraries[i];
+                    // Load each library and inject all symbols in the 'local=1' environment
+                    let includeEnv = include(library.name, env);
+                    for (const [k, v] of Object.entries(includeEnv.vars)) {
+                        if (!k.startsWith("thy_")) {// Do not retrieve system variables
+                            env.assign(k, v, null, 1);
+                        }
+                    }
+                }
+                return;
             default:
                 if (Array.isArray(tree) && tree.length == 1) return (evaluate(tree[0], env));
                 throw new Error("Sorry - I don't know how to evaluate this: " + JSON.stringify(tree))
@@ -438,3 +473,49 @@ function multiply_string(s, n) {
     while (--n >= 0) result.push(s);
     return (result.join(''));
 }
+
+function include(name, env) {
+    let includeEnv = new Environment();
+    let has_fs = (typeof fs !== 'undefined' && typeof fs.readdirSync === 'function' && typeof fs.readFileSync === 'function');
+    if (!has_fs) {
+        console.warn("Dependencies not found to perform the import of '"+name+".rock'");
+        // We ignore the missing includes in web-browser mode.
+        return includeEnv;
+    }
+    let filename = resolve_include_file(name, env);
+    // Parse the file
+    let data = fs.readFileSync(filename, 'utf8');
+    let ast = parser.parse(data);
+    // Interpret the AST
+    includeEnv.input = env.input;
+    includeEnv.output = env.output;
+    includeEnv.assign("thy_location", filename, null, 1);
+    includeEnv.assign("thy_name", name, null, 1);
+    includeEnv.run(ast);// We don't care about a return value.
+    return includeEnv;
+}
+
+function resolve_include_file(name, env) {
+    let currentRockFilename = null;
+    if (env.exists("thy_location")) {
+        // Each file must know its location, to find it's relative rock libraries
+        currentRockFilename = env.vars["thy_location"];
+    } else {
+        // Best effort: including in the current path will probably fail
+        currentRockFilename = path.join(thy_dirname, "anonymous.rock");
+    }
+    let currentRockDirname = path.dirname(currentRockFilename);
+    let files = fs.readdirSync(currentRockDirname);
+    let filename = null;
+    basename_i = name + ".rock";
+    for (i = 0; i < files.length; ++i) {
+        let file = files[i];
+        if (file.toLowerCase() === basename_i) {
+            filename = path.join(currentRockDirname, file);
+            if (filename === currentRockFilename) throw ("The file '"+currentRockFilename+"' is including itself");
+            break;
+        }
+    }
+    if (filename == null) throw ("Include file not found: " + path.join(currentRockDirname, basename_i));
+    return path.resolve(filename);// Absolute path
+}
diff --git a/satriani/satriani.js b/satriani/satriani.js
@@ -1,13 +1,19 @@
 const parser = require('./satriani.parser.js');
 const interpreter = require('./satriani.interpreter.js');
+const path = require('path');
 
 module.exports = {
     Interpreter : function() {
-        this.run = function(program, input, output) {
+        this.run = function(program, input, output, file) {
             if (typeof(program) == 'string') program = this.parse(program);
             let env = new interpreter.Environment();
             env.output = output || console.log;
             env.input = input || (() => "");
+            if (file == undefined) {
+                file = path.join(__dirname, "anonymous.rock");
+            }
+            file = path.resolve(file);// Absolute path
+            env.assign("thy_location", file, null, 1);
             return env.run(program);
         }