1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
|
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>14_Advanced_Combinators - Documentation</title>
<script src="scripts/prettify/prettify.js"></script>
<script src="scripts/prettify/lang-css.js"></script>
<!--[if lt IE 9]>
<script src="//html5shiv.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
<link type="text/css" rel="stylesheet" href="https://code.ionicframework.com/ionicons/2.0.1/css/ionicons.min.css">
<link type="text/css" rel="stylesheet" href="styles/prettify-tomorrow.css">
<link type="text/css" rel="stylesheet" href="styles/jsdoc-default.css">
</head>
<body>
<input type="checkbox" id="nav-trigger" class="nav-trigger" />
<label for="nav-trigger" class="navicon-button x">
<div class="navicon"></div>
</label>
<label for="nav-trigger" class="overlay"></label>
<nav>
<li class="nav-link nav-home-link"><a href="index.html">Home</a></li><li class="nav-heading">Tutorials</li><li class="nav-item"><a href="tutorial-00_Introduction.html">00_Introduction</a></li><li class="nav-item"><a href="tutorial-01_Function_Calls.html">01_Function_Calls</a></li><li class="nav-item"><a href="tutorial-02_Function_Composition.html">02_Function_Composition</a></li><li class="nav-item"><a href="tutorial-03_Table_Operations.html">03_Table_Operations</a></li><li class="nav-item"><a href="tutorial-04_Currying.html">04_Currying</a></li><li class="nav-item"><a href="tutorial-05_Pattern_Matching.html">05_Pattern_Matching</a></li><li class="nav-item"><a href="tutorial-06_Immutable_Tables.html">06_Immutable_Tables</a></li><li class="nav-item"><a href="tutorial-07_Function_References.html">07_Function_References</a></li><li class="nav-item"><a href="tutorial-08_Combinators.html">08_Combinators</a></li><li class="nav-item"><a href="tutorial-09_Expression_Based.html">09_Expression_Based</a></li><li class="nav-item"><a href="tutorial-10_Tables_Deep_Dive.html">10_Tables_Deep_Dive</a></li><li class="nav-item"><a href="tutorial-11_Standard_Library.html">11_Standard_Library</a></li><li class="nav-item"><a href="tutorial-12_IO_Operations.html">12_IO_Operations</a></li><li class="nav-item"><a href="tutorial-13_Error_Handling.html">13_Error_Handling</a></li><li class="nav-item"><a href="tutorial-14_Advanced_Combinators.html">14_Advanced_Combinators</a></li><li class="nav-item"><a href="tutorial-15_Integration_Patterns.html">15_Integration_Patterns</a></li><li class="nav-item"><a href="tutorial-16_Best_Practices.html">16_Best_Practices</a></li><li class="nav-item"><a href="tutorial-README.html">README</a></li><li class="nav-heading"><a href="global.html">Globals</a></li><li class="nav-item"><span class="nav-item-type type-member">M</span><span class="nav-item-name"><a href="global.html#callStackTracker">callStackTracker</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#debugError">debugError</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#debugLog">debugLog</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#executeFile">executeFile</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#initializeStandardLibrary">initializeStandardLibrary</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#interpreter">interpreter</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#lexer">lexer</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#main">main</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#parser">parser</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#readFile">readFile</a></span></li><li class="nav-item"><span class="nav-item-type type-function">F</span><span class="nav-item-name"><a href="global.html#run">run</a></span></li>
</nav>
<div id="main">
<h1 class="page-title">14_Advanced_Combinators</h1>
<section>
<header>
</header>
<article>
<h1>Advanced Combinators</h1>
<h2>What are Advanced Combinators?</h2>
<p>Advanced combinators are powerful patterns that combine multiple functions and operations to solve complex problems. They build on the basic combinators you've already learned.</p>
<h2>Partial Application and Currying</h2>
<h3>Creating Specialized Functions</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Basic partial application */
add : x y -> x + y;
add_ten : add 10;
result : add_ten 5; /* 15 */
/* Complex partial application */
format_with_prefix : prefix value -> prefix + ": " + value;
format_name : format_with_prefix "Name";
format_age : format_with_prefix "Age";
person : {name: "Alice", age: 30};
formatted_name : format_name person.name; /* "Name: Alice" */
formatted_age : format_age person.age; /* "Age: 30" */
</code></pre>
<h3>Currying with Combinators</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Create specialized functions */
multiply_by : x y -> x * y;
double : multiply_by 2;
triple : multiply_by 3;
numbers : {1, 2, 3, 4, 5};
doubled : map @double numbers; /* {2, 4, 6, 8, 10} */
tripled : map @triple numbers; /* {3, 6, 9, 12, 15} */
</code></pre>
<h2>Higher-Order Combinators</h2>
<h3>Combinators that Work with Other Combinators</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Apply a combinator to multiple collections */
apply_to_all : combinator collections ->
reduce @t.merge {} (map @combinator collections);
/* Example usage */
add_one : x -> x + 1;
collections : {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
all_incremented : apply_to_all @map @add_one collections;
/* Result: {1: 2, 2: 3, 3: 4, 4: 5, 5: 6, 6: 7, 7: 8, 8: 9, 9: 10} */
</code></pre>
<h3>Composing Multiple Functions</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Compose many functions together */
compose_many : functions ->
reduce @compose @identity functions;
/* Example usage */
double_then_increment : compose @increment @double;
complex_transform : compose @double_then_increment @square;
result : complex_transform 3;
/* Result: 19 (3^2=9, 9*2=18, 18+1=19) */
</code></pre>
<h2>Memoization Pattern</h2>
<h3>Caching Function Results</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Simple memoization */
memoize : f -> {
cache: {},
compute: x ->
when t.has cache x then t.get cache x
_ then {
result: f x,
new_cache: t.set cache x (f x)
}
};
/* Using memoized function */
expensive_calc : x -> x * x * x; /* Simulate expensive computation */
memoized_calc : memoize @expensive_calc;
result1 : memoized_calc.compute 5; /* Computes 125 */
result2 : memoized_calc.compute 5; /* Uses cached result */
</code></pre>
<h2>Real-World Problem Solving</h2>
<h3>E-commerce Order Processing</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Process customer orders */
orders : {
order1: {customer: "Alice", items: {book: 2, pen: 5}, status: "pending"},
order2: {customer: "Bob", items: {laptop: 1}, status: "shipped"},
order3: {customer: "Charlie", items: {book: 1, pen: 3}, status: "pending"}
};
prices : {book: 15, pen: 2, laptop: 800};
/* Calculate order totals */
calculate_total : order -> {
customer: order.customer,
total: reduce @add 0 (map @calculate_item_total order.items),
status: order.status
};
calculate_item_total : item quantity ->
when item is
"book" then 15 * quantity
"pen" then 2 * quantity
"laptop" then 800 * quantity
_ then 0;
/* Process all orders */
processed_orders : map @calculate_total orders;
..out processed_orders;
</code></pre>
<h3>Data Transformation Pipeline</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Transform user data through multiple stages */
users : {
alice: {name: "Alice", age: 25, city: "NYC", active: true},
bob: {name: "Bob", age: 30, city: "LA", active: false},
charlie: {name: "Charlie", age: 35, city: "NYC", active: true}
};
/* Pipeline stages */
filter_active : users -> filter @is_active users;
add_greeting : users -> map @add_greeting_to_user users;
format_output : users -> map @format_user_output users;
is_active : user -> user.active;
add_greeting_to_user : user -> t.merge user {greeting: "Hello, " + user.name};
format_user_output : user -> {
name: user.name,
greeting: user.greeting,
location: user.city
};
/* Execute pipeline */
active_users : filter_active users;
greeted_users : add_greeting active_users;
formatted_users : format_output greeted_users;
..out formatted_users;
</code></pre>
<h2>Advanced Patterns</h2>
<h3>Lazy Evaluation</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Lazy evaluation with thunks */
lazy : computation -> {
compute: computation,
evaluated: false,
result: null,
get: ->
when evaluated then result
_ then {
computed_result: compute,
new_lazy: {
compute: computation,
evaluated: true,
result: computed_result,
get: -> computed_result
}
}
};
/* Use lazy evaluation */
expensive_operation : -> {
/* Simulate expensive computation */
..out "Computing...";
42
};
lazy_result : lazy expensive_operation;
/* Computation hasn't happened yet */
actual_result : lazy_result.get;
/* Now computation happens */
</code></pre>
<h3>Continuation-Passing Style</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Continuation-passing style for complex control flow */
process_with_continuation : data success_cont error_cont ->
when data = null then error_cont "No data provided"
_ then
processed : transform data;
when processed.error is
true then error_cont processed.message
false then success_cont processed.result;
/* Use continuations */
success_handler : result -> ..out "Success: " + result;
error_handler : error -> ..out "Error: " + error;
process_with_continuation "valid data" success_handler error_handler;
process_with_continuation null success_handler error_handler;
</code></pre>
<h2>Performance Optimization</h2>
<h3>Avoiding Redundant Computations</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Cache expensive computations */
expensive_transform : data ->
/* Simulate expensive operation */
data * data * data;
/* With caching */
transform_with_cache : {
cache: {},
transform: data ->
when t.has cache data then t.get cache data
_ then {
result: expensive_transform data,
new_cache: t.set cache data (expensive_transform data)
}
};
/* Use cached version */
result1 : transform_with_cache.transform 5; /* Computes */
result2 : transform_with_cache.transform 5; /* Uses cache */
</code></pre>
<h3>Lazy Collections</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Lazy collection processing */
lazy_map : f collection -> {
f: f,
collection: collection,
get: index ->
when index >= t.length collection then null
_ then f (t.get collection index)
};
/* Use lazy mapping */
numbers : {1, 2, 3, 4, 5};
expensive_double : x -> {
/* Simulate expensive operation */
..out "Doubling " + x;
x * 2
};
lazy_doubled : lazy_map @expensive_double numbers;
/* No computation yet */
first_result : lazy_doubled.get 0; /* Only computes for index 0 */
</code></pre>
<h2>Best Practices</h2>
<h3>Keep Combinators Focused</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Good: Single responsibility */
filter_by_age : min_age users ->
filter @(is_older_than min_age) users;
is_older_than : min_age user -> user.age >= min_age;
/* Avoid: Multiple responsibilities */
bad_filter : min_age max_age users ->
filter @(complex_age_check min_age max_age) users;
</code></pre>
<h3>Use Descriptive Names</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Good: Clear intent */
process_active_users : users ->
filter @is_active (map @add_user_id users);
/* Avoid: Generic names */
process : data ->
filter @check (map @transform data);
</code></pre>
<h3>Compose, Don't Nest</h3>
<pre class="prettyprint source lang-plaintext"><code>/* Good: Composed functions */
pipeline : compose @format_output (compose @add_metadata (filter @is_valid data));
/* Avoid: Deep nesting */
nested : format_output (add_metadata (filter @is_valid data));
</code></pre>
<h2>Next Steps</h2>
<p>Now that you understand advanced combinators, explore:</p>
<ul>
<li><a href="15_Integration_Patterns.md">Integration Patterns</a> for external system integration</li>
<li><a href="13_Error_Handling.md">Error Handling</a> for robust error management</li>
<li><a href="16_Best_Practices.md">Best Practices</a> for writing clean code</li>
</ul>
</article>
</section>
</div>
<br class="clear">
<footer>
Generated by <a href="https://github.com/jsdoc3/jsdoc">JSDoc 4.0.4</a> on Tue Jul 29 2025 23:15:00 GMT-0400 (Eastern Daylight Time) using the Minami theme.
</footer>
<script>prettyPrint();</script>
<script src="scripts/linenumber.js"></script>
</body>
</html>
|