Merge pull request #159 from /issues/158

Fixes #158; Adds Python example

README.md

@@ -18,7 +18,7 @@ Parsimmon supports IE7 and newer browsers, along with [Node.js][]. It can be use
 
 ## Examples
 
-See the [examples][] directory for annotated examples of parsing JSON, Lisp, and math.
+See the [examples][] directory for annotated examples of parsing JSON, Lisp, a Python-ish language, and math.
 
 ## Basics
 

examples/.eslintrc

@@ -1,6 +1,7 @@
 {
   "env": {
-    "node": true
+    "node": true,
+    "es6": true
   },
   "rules": {
     "no-console": "off"

examples/json.js

@@ -1,11 +1,9 @@
-var fs = require('fs');
-var path = require('path');
 var util = require('util');
-var P = require('../src/parsimmon');
+var P = require('..');
 
 ///////////////////////////////////////////////////////////////////////
 
-// Turn escaped characters into real ones (e.g. "\\n" becoems "\n").
+// Turn escaped characters into real ones (e.g. "\\n" becomes "\n").
 function interpretEscapes(str) {
   var escapes = {
     b: '\b',
@@ -96,18 +94,27 @@ var object =
 
 ///////////////////////////////////////////////////////////////////////
 
-var source = process.argv[2] || path.resolve(__dirname, '..', 'package.json');
-var result = json.parse(fs.readFileSync(source, 'utf-8'));
+var text = `\
+{
+  "id": "a thing\\nice\tab",
+  "another property!"
+    : "also cool"
+  , "weird formatting is ok too........😂": 123.45e1,
+  "": [
+    true, false, null,
+    "",
+    " ",
+    {},
+    {"": {}}
+  ]
+}
+`;
 
 function prettyPrint(x) {
-  console.log(util.inspect(x, {depth: null, colors: 'auto'}));
+  var opts = {depth: null, colors: 'auto'};
+  var s = util.inspect(x, opts);
+  console.log(s);
 }
 
-if (result.status) {
-  prettyPrint(result.value);
-} else {
-  console.log('Parse failure');
-  console.log('=============');
-  console.log();
-  prettyPrint(result);
-}
+var ast = json.tryParse(text);
+prettyPrint(ast);

examples/lisp.js

@@ -1,6 +1,5 @@
-var fs = require('fs');
 var util = require('util');
-var P = require('../src/parsimmon');
+var P = require('../');
 
 ///////////////////////////////////////////////////////////////////////
 
@@ -38,18 +37,15 @@ var Lisp = spaced(LExpression);
 
 ///////////////////////////////////////////////////////////////////////
 
-var source = process.argv[2];
-var result = Lisp.parse(fs.readFileSync(source, 'utf-8'));
+var text = `\
+(list 1 2 (cons 1 (list)))
+`;
 
 function prettyPrint(x) {
-  console.log(util.inspect(x, {depth: null, colors: 'auto'}));
+  var opts = {depth: null, colors: 'auto'};
+  var s = util.inspect(x, opts);
+  console.log(s);
 }
 
-if (result.status) {
-  prettyPrint(result.value);
-} else {
-  console.log('Parse failure');
-  console.log('=============');
-  console.log();
-  prettyPrint(result);
-}
+var ast = Lisp.tryParse(text);
+prettyPrint(ast);

examples/math.js

@@ -1,6 +1,5 @@
-var fs = require('fs');
 var util = require('util');
-var P = require('../src/parsimmon');
+var P = require('..');
 
 // This parser supports basic math with + - * / ^, unary negation, factorial,
 // and parentheses. It does not evaluate the math, just turn it into a series of
@@ -166,18 +165,15 @@ var MyMath = spaced(tableParser);
 
 ///////////////////////////////////////////////////////////////////////
 
-var source = process.argv[2];
-var result = MyMath.parse(fs.readFileSync(source, 'utf-8'));
+var text = `\
+2 + 3 * 4 / 1 - 3 ^ (2!)
+`;
 
 function prettyPrint(x) {
-  console.log(util.inspect(x, {depth: null, colors: 'auto'}));
+  var opts = {depth: null, colors: 'auto'};
+  var s = util.inspect(x, opts);
+  console.log(s);
 }
 
-if (result.status) {
-  prettyPrint(result.value);
-} else {
-  console.log('Parse failure');
-  console.log('=============');
-  console.log();
-  prettyPrint(result);
-}
+var ast = MyMath.tryParse(text);
+prettyPrint(ast);

examples/python-ish.js

@@ -0,0 +1,72 @@
+var util = require('util');
+var P = require('..');
+
+///////////////////////////////////////////////////////////////////////
+
+// If this were actually Python, "Block" wouldn't be a statement on its own,
+// but rather "If" and "While" would be statements that used "Block" inside.
+var Statement =
+  P.lazy(function() {
+    return P.alt(ExpressionStatement, Block);
+  });
+
+// Just a simple `foo()` style function call.
+var FunctionCall =
+  P.regexp(/[a-z]+/).skip(P.string('()'))
+    .map(function(s) { return ['FunctionCall', s]; })
+    .desc('a function call');
+
+// To make it a statement we just need a newline afterward.
+var ExpressionStatement =
+  FunctionCall.skip(P.string('\n'));
+
+// The general idea of this is to assume there's "block:" on its own line,
+// then we capture the whitespace used to indent the first statement of the
+// block, and require that every other statement has the same exact string of
+// indentation in front of it.
+var Block =
+  P.seq(
+    P.string('block:\n'),
+    P.regexp(/[ ]+/),
+    Statement
+  ).chain(function(args) {
+    // `.chain` is called after a parser succeeds. It returns the next parser
+    // to use for parsing. This allows subsequent parsing to be dependent on
+    // previous text.
+    var indent = args[1];
+    var statement = args[2];
+    return P.string(indent).then(Statement).many()
+      .map(function(statements) {
+        return [statement].concat(statements);
+      });
+  })
+  .map(function(statements) {
+    return ['Block', statements];
+  });
+
+///////////////////////////////////////////////////////////////////////
+
+var text = `\
+block:
+    a()
+    b()
+    c()
+    block:
+        d()
+        e()
+        f()
+    block:
+        g()
+        h()
+        i()
+        j()
+`;
+
+function prettyPrint(x) {
+  var opts = {depth: null, colors: 'auto'};
+  var s = util.inspect(x, opts);
+  console.log(s);
+}
+
+var ast = Block.tryParse(text);
+prettyPrint(ast);