https://github.com/jobs-github/escript

Last synced: 5 months ago
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Host: GitHub
URL: https://github.com/jobs-github/escript
Owner: jobs-github
Created: 2022-07-25T15:30:00.000Z (almost 4 years ago)
Default Branch: master
Last Pushed: 2023-04-24T15:11:15.000Z (about 3 years ago)
Last Synced: 2024-06-20T05:13:05.766Z (about 2 years ago)
Language: Go
Size: 318 KB
Stars: 0
Watchers: 1
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
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README

          


- [escript - an embedded script for Go](#escript---a-embedded-script-for-go)

  - [Features](#features)

  - [Quick Start](#quick-start)

    - [run interactive interpreter](#run-interactive-interpreter)

    - [run scripts](#run-scripts)

    - [conditional expression](#conditional-expression)

    - [recursion](#recursion)

    - [closure](#closure)

    - [eval](#eval)

    - [embedded eval](#embedded-eval)

    - [dump \& load AST as json](#dump--load-ast-as-json)

  - [builtin function](#builtin-function)

    - [type](#type)

    - [str](#str)

    - [print](#print)

    - [println](#println)

    - [printf](#printf)

    - [sprintf](#sprintf)

    - [loads](#loads)

    - [dumps](#dumps)

    - [loop](#loop)

    - [map](#map)

    - [reduce](#reduce)

    - [filter](#filter)

    - [range](#range)

  - [types](#types)

    - [null](#null)

    - [boolean](#boolean)

    - [integer](#integer)

    - [string](#string)

    - [array](#array)

    - [hash](#hash)

    - [builtin](#builtin)

    - [function](#function)

    - [method](#method)

  - [License](#license)

  - [Author](#author)

  - [More](#more)

# escript - an embedded script for Go #

escript is a tiny, expression-based embedded language for Go.

    package main

    import (

        "fmt"

        "github.com/jobs-github/escript"

    )

    func main() {

        code := `const r = (1 > 0) ? (1 + 1) : (10 % 3); println(r);`

        r, _ := escript.NewState(code)

        res, _ := r.Run(nil)

        fmt.Println(res)

    }

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## Features ##

* go-like syntax (also borrow some from python/c)

* variable bindings

* arithmetic expressions

* built-in functions

* first-class and higher-order functions (closure)

* conditional expression

* object member call

* eval AST

* dump & load AST as json

* data types

    * integer

    * boolean

    * string

    * array

    * hash

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## Quick Start ##

### run interactive interpreter ###

    chmod +x /make.sh

    ./make.sh

    ./escript

    

**Note** : you can change `useVM` in `repl/main.go` to choose default interpreter.  

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### run scripts ###

    chmod +x /make.sh

    ./make.sh

    ./escript scripts/hello.es

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### [conditional expression](scripts/conditional.es) ###

    (1 > 0) ? (1 + 1) : (10 % 3)

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### [recursion](scripts/mapreduce.es) ###

    func map_iter(arr, accumulated, fn) {

        (arr.len() == 0) ? accumulated : map_iter(arr.tail(), accumulated.push(fn(arr.first())), fn);

    };

    func my_map(arr, fn) {

        map_iter(arr, [], fn);

    };

    func double(x) {

        x * 2;

    };

    func my_reduce(arr, result, fn) {

        (arr.len() == 0) ? result : my_reduce(arr.tail(), fn(result, arr.first()), fn);

    };

    func add(x, y) {

        x + y;

    };

    func sum(arr) {

        my_reduce(arr, 0, add);

    };

    const a = [1,2,3,4,5];

    const result = my_map(a, double);

    println(result);

    const rc = sum([1,2,3,4,5]);

    println(rc);

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### [closure](scripts/closure.es) ###

    const r = func (x) {

        x * 2;

    }(2);

    println(r);

    func add(x) {

        func(y) {

            x + y;

        };

    };

    const fn = add(1);

    println(fn(2));

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### eval ###

    package main

    import (

        "fmt"

        "github.com/jobs-github/escript"

    )

    func main() {

        code := `const r = (1 > 0) ? (1 + 1) : (10 % 3); println(r);`

        r, _ := escript.NewState(code)

        res, _ := r.Run(nil)

        fmt.Println(res)

    }

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### embedded eval ###

    package main

    import (

        "fmt"

        "github.com/jobs-github/escript"

        "github.com/jobs-github/escript/object"

    )

    func main() {

        T := func() (object.Object, error) { return object.True, nil }

        F := func() (object.Object, error) { return object.False, nil }

        r, _ := escript.NewState(`($a || $b) && ($c || $d);`)

        res, _ := r.Run(object.Symbols{"a": T, "b": T, "c": T, "d": F})

        fmt.Println(res)

    }

### dump & load AST as json ###

dump AST as json:  

    chmod +x /make.sh

    ./make.sh

    ./escript --dump scripts/conditional.es > scripts/conditional.json

load & eval AST from json:  

    chmod +x /make.sh

    ./make.sh

    ./escript --load scripts/conditional.json

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## [builtin function](builtin/builtin.go) ##

### type ###

    const s = "EOF";

    println(type(s));

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### str ###

    const arr = [1,2,3];

    println(str(arr));

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### print ###

    print("123 ", 456, " ", [7,8,9]);

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### println ###

    println("aaa ", 111, " ", {"k1": 1, "k2": "2"});

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### printf ###

    const testi = 999;

    const tests = "2022";

    printf("%v\n%v\n", testi, tests);

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### sprintf ###

    const testi2 = 9999;

    const tests2 = "2222";

    const ms = sprintf("%v-%v", testi, tests);

    println(ms);

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### [loads](scripts/json.es) ###

    const s = "{\"k3\":{\"k31\":true,\"k32\":[1,2,3]},\"k2\":\"2\",\"k1\":1}"; 

    const obj = loads(s);

    println(obj);

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### [dumps](scripts/json.es) ###

    const obj1 = { "k1": null, "k2": 123 };

    const objstr = dumps(obj1);

    println(objstr);

### [loop](scripts/loop.es) ###

    loop(10, func(i){

        i < 5 ? println(i) : println(i * i)

    });

### [map](scripts/array.es) ###

    const arr = [1,2,3];

    const r = map(arr, func(i, item) { item * 2 });

    println(r);

### [reduce](scripts/array.es) ###

    const arr = [1,2,3];

    const acc = reduce(arr, func(x, y) { x + y }, 0);

    println(acc);

### [filter](scripts/array.es) ###

    const arr = [1,2,3];

    const fr = filter(arr, func(i, item) { item > 1 });

    println(fr);

### [range](scripts/array.es) ###

    println(range(10, func(i) { 

        sprintf("key_%v", (i % 2 == 0) ? i * 2 : i)

    }));

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## [types](object/def.go) ##

### [null](object/null.go) ###

method  |comment

--------|-------

not     |!

    >> const n = null;

    >> n.not();

    true

    >> !n;

    true

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### [boolean](object/boolean.go) ###

method  |comment

--------|-------

not     |!

neg|-

int     |convert to int

    >> const b = true;

    true

    >> b.not()

    false

    >> b.neg()

    -1

    >> b.int()

    1

    >> !b

    false

    >> -b

    -1

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### [integer](object/integer.go) ###

method  |comment

--------|-------

not     |!

neg|-

int     |convert to int

    >> const i = 123

    123

    >> i.not()

    false

    >> i.neg()

    -123

    >> i.int()

    123

    >> !i

    false

    >> -i

    -123

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### [string](object/string.go) ###

method  |comment

--------|-------

len     |length of string

index   |get value by index

not     |!

int     |convert to int

    >> const s = "123"

    123

    >> s.len()

    3

    >> s.index(1)

    2

    >> s.not()

    false

    >> s.int()

    123

    >> s[1]

    2

    >> !s

    false

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### [array](object/array.go) ###

method  |comment

--------|-------

len     |length of array

index   |get value by index

not     |!

first   |first value

last    |last value

tail    |remove first value and return rest

push    |append value

    >> const arr = [1,2,3,4,5]

    [1, 2, 3, 4, 5]

    >> arr.push("hello")

    [1, 2, 3, 4, 5, hello]

    >> arr.len()

    6

    >> arr[0]

    1

    >> arr.not()

    false

    >> !arr

    false

    >> arr.first()

    1

    >> arr.last()

    hello

    >> arr.tail()

    [2, 3, 4, 5, hello]

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### [hash](object/hash.go) ###

method  |comment

--------|-------

len     |length of hash pairs

index   |get value by key

keys    |get keys

not     |!

    >> const h = {"k1": 1, "k2": "bbb", "k3": [1,2,3]}

    {k1: 1, k2: bbb, k3: [1, 2, 3]}

    >> h["k1"]

    1

    >> h.len()

    3

    >> h.not()

    false

    >> h.index("k1")

    1000

    >> !h

    false

    >> h.keys()

    [k1, k2, k3]

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### [builtin](object/builtin.go) ###

method  |comment

--------|-------

not     |!

    >> const t = type

    

    >> const s = "123"

    123

    >> t(s)

    string

    >> t.not()

    false

    >> !t

    false

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### [function](object/function.go) ###

method  |comment

--------|-------

not     |!

    >> const fn = func(x, y) { x + y; }

    closure[0xc000425260]

    >> fn(1,2)

    3

    >> !fn

    false

    >> fn.not()

    false

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### [method](object/objectfunc.go) ###

method  |comment

--------|-------

not     |!

    >> const arr = [1,2,3]

    [1, 2, 3]

    >> const fn = arr.index

    

    >> fn(1)

    2

    >> !fn

    false

    >> fn.not()

    false

    >> const l = arr.len

    

    >> l()

    3

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## License ##

escript is licensed under [New BSD License](https://opensource.org/licenses/BSD-3-Clause), a very flexible license to use.

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## Author ##

* chengzhuo (jobs, yao050421103@163.com)  

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## More ##

- [Writing A Compiler In Go](https://compilerbook.com/)  

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