diff --git a/interpreter-test.html b/interpreter-test.html
new file mode 100644
index 0000000..eb38ca8
--- /dev/null
+++ b/interpreter-test.html
@@ -0,0 +1,6 @@
+
+
+
+
+
+
diff --git a/interpreter.js b/interpreter.js
new file mode 100644
index 0000000..8c9896f
--- /dev/null
+++ b/interpreter.js
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+"use strict";
+(function(){
+ var variables = [];
+ var functions = [];
+ var file = "[anonymous]";
+
+
+ function executeCommand(args, std) {
+ console.log(args, std);
+ }
+
+ function astSequence() {
+ let commands = [];
+ return {
+ add: c => commands.push(c),
+ execute: (std) => commands.forEach(c => c.execute(std)),
+ }
+ }
+
+ function astCommand() {
+ let args = [];
+ return {
+ add: a => args.push(a),
+ execute: (std) => {
+ let evaluatedArgs = args.map(a => a.evaluate());
+ executeCommand(evaluatedArgs, std);
+ },
+ };
+ }
+
+ function astValueCompound() {
+ let components = [];
+ return {
+ add: c => components.push(c),
+ evaluate: () => components.map(c => c.evaluate()).join(""),
+ };
+ }
+
+ function astValueString(str) {
+ return {
+ evaluate: () => str,
+ };
+ }
+
+ function astValueVar(name) {
+ return {
+ // add support for multiple arguments in one variable
+ evaluate: () => variables[name],
+ }
+ }
+
+ function astValueCommandSubstitution(ast) {
+ return {
+ evaluate: () => {
+ // TODO
+ },
+ };
+ }
+
+ function astValueProcessSubstitution(ast) {
+ return {
+ evaluate: () => {
+ // TODO
+ },
+ };
+ }
+
+ function panic(line, message) {
+ throw `${file}: line ${line}: panic: ${message}`;
+ }
+
+ function syntaxError(line, message) {
+ throw `${file}: line ${line}: syntax error: ${message}`;
+ }
+
+ function parseCommands(content) {
+ let line = 1;
+
+ const PS_INIT = 0;
+ const PS_COMMENT = -1;
+ const PS_COMMAND = 1;
+
+ let astRoot = astSequence();
+ let current = null;
+
+ let state = PS_INIT;
+ let buffer = "";
+
+ const length = content.length;
+ for (let i = 0; i < length; i++) {
+ const c = content[i];
+ switch(state) {
+ case PS_INIT:
+ if (['\n', '\r', ' ', '\t', ';'].includes(c)) {
+ // continue
+ } else if (c == '#') {
+ state = PS_COMMENT;
+ } else {
+ current = astCommand();
+ buffer = c;
+ state = PS_COMMAND;
+ }
+ break;
+ case PS_COMMENT:
+ if (c == '\n') {
+ state = PS_INIT;
+ }
+ break;
+ case PS_COMMAND:
+ // check for escape and quotes
+ if (c == ';' || c == '\n') {
+ if (buffer) {
+ current.add(astValueString(buffer));
+ buffer = "";
+ }
+ astRoot.add(current);
+ current = null;
+ state = PS_INIT;
+ } else if (c == ' ' || c == '\t') {
+ if (buffer) {
+ current.add(astValueString(buffer));
+ buffer = "";
+ }
+ } else {
+ buffer += c;
+ }
+ break;
+ default:
+ panic(line, "unknown parse state");
+ break;
+ }
+ if (c == '\n') {
+ line++;
+ }
+ }
+
+ return astRoot;
+ }
+
+ window.sh = {
+ parse: parseCommands,
+ };
+})();