10 files changed, 99 insertions, 3 deletions
diff --git a/lambda-calcul/javascript/index.js b/lambda-calcul/javascript/index.js
index e06ac4d..a71697d 100644
--- a/lambda-calcul/javascript/index.js
+++ b/lambda-calcul/javascript/index.js
@@ -8,6 +8,8 @@ client = LC.newClient({
 });
 
 client.start()
-  .then((token) => console.log(`${playerName} has registered with token ${token}`) || token)
+  .then(token => console.log(`${playerName} has registered with token ${token}`) || token)
   .then(client.nextChallenge)
-  .then((challenge) => console.log(`Next challenge: ${challenge}`));
+  .then(challenge => console.log(`Next challenge: ${challenge}`) || challenge)
+  .then(client.solve)
+  .then(solution => console.log(`… solved into: ${solution}`));
diff --git a/lambda-calcul/javascript/src/client.js b/lambda-calcul/javascript/src/client.js
index d046187..88ea253 100644
--- a/lambda-calcul/javascript/src/client.js
+++ b/lambda-calcul/javascript/src/client.js
@@ -1,11 +1,27 @@
 const axios = require('axios');
 
-const newClient = ({ playerName, challengerURL }) => {
+const defaultInterpreter = require('./interpreter');
+const defaultParser = require('./parser');
+const defaultPrinter = require('./printer');
+
+const newClient = ({
+  challengerURL,
+  interpreter = defaultInterpreter,
+  parser = defaultParser,
+  playerName,
+  printer = defaultPrinter,
+}) => {
   const nextChallenge = (token) => axios ({
     url: `${challengerURL}/api/challenge?token=${token}`,
   })
     .then(({ data: { expr } }) => expr);
 
+  const solve = (challenge) => {
+    const parsedExpression = parser.parse(challenge);
+    const evaluatedExpression = interpreter.evaluate(parsedExpression);
+    return printer.print(evaluatedExpression);
+  }
+
   const start = () => axios({
     method: 'POST',
     url: `${challengerURL}/api/register`,
@@ -16,6 +32,7 @@ const newClient = ({ playerName, challengerURL }) => {
 
   return {
     nextChallenge,
+    solve,
     start,
   };
 };
diff --git a/lambda-calcul/javascript/src/internals.js b/lambda-calcul/javascript/src/internals.js
new file mode 100644
index 0000000..f55736a
--- /dev/null
+++ b/lambda-calcul/javascript/src/internals.js
@@ -0,0 +1,5 @@
+const σ = (name) => ({ sym: name });
+
+module.exports = {
+  σ,
+};
diff --git a/lambda-calcul/javascript/src/interpreter.js b/lambda-calcul/javascript/src/interpreter.js
new file mode 100644
index 0000000..a2e8481
--- /dev/null
+++ b/lambda-calcul/javascript/src/interpreter.js
@@ -0,0 +1,7 @@
+const { σ } = require('./internals');
+
+const evaluate = (term) => term;
+
+module.exports = {
+  evaluate,
+};
diff --git a/lambda-calcul/javascript/src/parser.js b/lambda-calcul/javascript/src/parser.js
new file mode 100644
index 0000000..77593e0
--- /dev/null
+++ b/lambda-calcul/javascript/src/parser.js
@@ -0,0 +1,7 @@
+const { σ } = require('./internals');
+
+const parse = (x) => σ(x);
+
+module.exports = {
+  parse,
+};
diff --git a/lambda-calcul/javascript/src/printer.js b/lambda-calcul/javascript/src/printer.js
new file mode 100644
index 0000000..39dbf38
--- /dev/null
+++ b/lambda-calcul/javascript/src/printer.js
@@ -0,0 +1,5 @@
+const print = ({ sym: name }) => name;
+
+module.exports = {
+  print,
+};
diff --git a/lambda-calcul/javascript/test/client.test.js b/lambda-calcul/javascript/test/client.test.js
index 5fcc42c..8b68a61 100644
--- a/lambda-calcul/javascript/test/client.test.js
+++ b/lambda-calcul/javascript/test/client.test.js
@@ -54,4 +54,30 @@ describe('λ-calculator', () => {
     return client.nextChallenge('SomeToken')
       .then((challenge) => expect(challenge).toBe('SomeChallenge'));
   });
+
+  it('solves challenges', () => {
+    const parser = {
+      parse: (challenge) => {
+        expect(challenge).toBe('Some challenge');
+        return 'Parsed expression';
+      },
+    };
+
+    const interpreter = {
+      evaluate: (parsedExpression) => {
+        expect(parsedExpression).toBe('Parsed expression');
+        return 'Evaluated expression';
+      },
+    };
+
+    const printer = {
+      print: (evaluatedExpression) => {
+        expect(evaluatedExpression).toBe('Evaluated expression');
+        return 'Expression to print';
+      },
+    };
+
+    const client = LC.newClient({ parser, interpreter, printer });
+    expect(client.solve('Some challenge')).toBe('Expression to print');
+  });
 });
diff --git a/lambda-calcul/javascript/test/interpreter.test.js b/lambda-calcul/javascript/test/interpreter.test.js
new file mode 100644
index 0000000..a859bfe
--- /dev/null
+++ b/lambda-calcul/javascript/test/interpreter.test.js
@@ -0,0 +1,9 @@
+const { σ } = require('../src/internals');
+const { evaluate } = require('../src/interpreter');
+
+describe('An interpreter', () => {
+  it('evaluates symbols', () => {
+    expect(evaluate(σ('x'))).toEqual(σ('x'));
+    expect(evaluate(σ('y'))).toEqual(σ('y'));
+  });
+});
diff --git a/lambda-calcul/javascript/test/parser.test.js b/lambda-calcul/javascript/test/parser.test.js
new file mode 100644
index 0000000..e9cab60
--- /dev/null
+++ b/lambda-calcul/javascript/test/parser.test.js
@@ -0,0 +1,9 @@
+const { σ } = require('../src/internals');
+const { parse } = require('../src/parser');
+
+describe('A parser', () => {
+  it('parses symbols', () => {
+    expect(parse('x')).toEqual(σ('x'));
+    expect(parse('y')).toEqual(σ('y'));
+  });
+});
diff --git a/lambda-calcul/javascript/test/printer.test.js b/lambda-calcul/javascript/test/printer.test.js
new file mode 100644
index 0000000..1684d31
--- /dev/null
+++ b/lambda-calcul/javascript/test/printer.test.js
@@ -0,0 +1,9 @@
+const { σ } = require('../src/internals');
+const { print } = require('../src/printer');
+
+describe('A printer', () => {
+  it('prints symbols', () => {
+    expect(print(σ('x'))).toEqual('x');
+    expect(print(σ('y'))).toEqual('y');
+  });
+});