From 32b54c402fb748798170564eae647818bcabd1cb Mon Sep 17 00:00:00 2001 From: Jeff Date: Tue, 28 Nov 2023 11:38:40 -0500 Subject: [PATCH] Fix example; Write README --- README.md | 60 +++++++++++++++++-------------------------- std/list_functions.ds | 15 ++++++----- 2 files changed, 32 insertions(+), 43 deletions(-) diff --git a/README.md b/README.md index fdee138..77a72ed 100644 --- a/README.md +++ b/README.md @@ -28,7 +28,17 @@ if (random_boolean) { } ``` -Dust is an interpreted, strictly typed language with first class functions. It emphasises concurrency by allowing any group of statements to be executed in parallel. Dust includes built-in tooling to import and export data in a variety of formats, including JSON, TOML, YAML and CSV. +Dust enforces strict type checking to make sure your code is correct. Dust does *not* have a null type. + +```dust +fib = |i | { + if i <= 1 { + 1 + } else { + (fib i - 1) + (fib i - 2) + } +} +``` - [Dust](#dust) @@ -42,9 +52,9 @@ Dust is an interpreted, strictly typed language with first class functions. It e - [Lists](#lists) - [Maps](#maps) - [Loops](#loops) - - [Tables](#tables) - [Functions](#functions) - [Concurrency](#concurrency) + - [Acknowledgements](#acknowledgements) ## Features @@ -140,7 +150,6 @@ Variables have two parts: a key and a value. The key is always a string. The val - boolean - list - map -- table - function Here are some examples of variables in dust. @@ -207,56 +216,31 @@ for number in list { } ``` -### Tables - -Tables are strict collections, each row must have a value for each column. If a value is "missing" it should be set to an appropriate value for that type. For example, a string can be empty and a number can be set to zero. Dust table declarations consist of a list of column names, which are identifiers enclosed in pointed braces, followed by a list of rows. +An **async for** loop will run the loop operations in parallel using a thread pool. ```dust -animals = table [ - ["rover" "cat" 14] - ["spot" "snake" 9] - ["bob" "giraffe" 2] -] -``` - -Querying a table is similar to SQL. - -```dust -names = select name from animals -youngins = select species from animals { - age <= 10 +async for i in [1 2 3 4 5 6 7 8 9 0] { + (output i) } ``` -The keywords `table` and `insert` make sure that all of the memory used to hold the rows is allocated at once, so it is good practice to group your rows together instead of using a call for each row. - -```dust -insert into animals [ - ["eliza" "ostrich" 4] - ["pat" "white rhino" 7] - ["jim" "walrus" 9] -] - -(assert_equal 6 (length animals)) -``` - ### Functions Functions are first-class values in dust, so they are assigned to variables like any other value. ```dust -# This simple function has no arguments. -say_hi = || => { +# This simple function has no arguments and no return type. +say_hi = || { (output "hi") } -# This function has one argument and will return a value. -add_one = |number| => { +# This function has one argument and will return an integer. +add_one = |number| { number + 1 } (say_hi) -(assert_equal (add_one 3), 4) +(assert_equal 4 (add_one 3)) ``` You don't need commas when listing arguments and you don't need to add whitespace inside the function body but doing so may make your code easier to read. @@ -274,6 +258,8 @@ async { } ``` +If the final statement in an async block creates a value, the block will return that value just like in a normal block. + ```dust data = async { (output "Reading a file...") @@ -281,7 +267,7 @@ data = async { } ``` -### Acknowledgements +## Acknowledgements Dust began as a fork of [evalexpr]. Some of the original code is still in place but the project has dramatically changed and no longer uses any of its parsing or interpreting. diff --git a/std/list_functions.ds b/std/list_functions.ds index a79f09f..db7b766 100644 --- a/std/list_functions.ds +++ b/std/list_functions.ds @@ -1,20 +1,23 @@ -find = |list function| => { - for i in list { +find = |items function | { + for i in items { if (function i) { return i } } } -map = |list function| => { +map = |items function | { new_list = [] - for i in list { + for i in items { new_list += (function i) } new_list } -[0 1 2] -> (map |i| => { i - 1}) - -> (find |i| => { i == 1 }) +foobar = [0 1 2] + -> (map |i | { i - 1 }) + -> (find |i | { i == -1 }) + +foobar