Fixes after writing the slides.
This commit is contained in:
parent
1cf90c8b38
commit
8c0a25bdb5
@ -18,9 +18,9 @@ is provided, but the type of an access function contains both.
|
||||
|
||||
The type of the contract parameter and the storage are up to the
|
||||
contract designer, but the type for list operations is not. The return
|
||||
type of an entrypoint is as follows, assuming that the type `storage`
|
||||
has been defined elsewhere. (Note that you can use any type with any
|
||||
name for the storage.)
|
||||
type of an access function is as follows, assuming that the type
|
||||
`storage` has been defined elsewhere. (Note that you can use any type
|
||||
with any name for the storage.)
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
@ -45,9 +45,10 @@ type return = (list (operation), storage);
|
||||
The contract storage can only be modified by activating an access
|
||||
function. It is important to understand what that means. What it does
|
||||
*not* mean is that some global variable holding the storage is
|
||||
modified by the entrypoint. Instead, what it *does* mean is that,
|
||||
given the state of the storage *on-chain*, an entrypoint specifies how
|
||||
to create another state for it, depending on a parameter.
|
||||
modified by the access function. Instead, what it *does* mean is that,
|
||||
given the state of the storage *on-chain*, an access function
|
||||
specifies how to create another state for it, depending on a
|
||||
parameter.
|
||||
|
||||
Here is an example where the storage is a single natural number that
|
||||
is updated by the parameter.
|
||||
@ -57,28 +58,32 @@ is updated by the parameter.
|
||||
<!--PascaLIGO-->
|
||||
|
||||
```pascaligo group=a
|
||||
type parameter is nat
|
||||
type storage is nat
|
||||
type return is list (operation) * storage
|
||||
|
||||
function save (const parameter : nat; const store : storage) : return is
|
||||
((nil : list (operation)), parameter)
|
||||
function save (const action : parameter; const store : storage) : return is
|
||||
((nil : list (operation)), store)
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo group=a
|
||||
type parameter = nat
|
||||
type storage = nat
|
||||
type return = operation list * storage
|
||||
|
||||
let save (parameter, store: nat * storage) : return =
|
||||
(([] : operation list), parameter)
|
||||
let save (action, store: parameter * storage) : return =
|
||||
(([] : operation list), store)
|
||||
```
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=a
|
||||
type parameter = nat;
|
||||
type storage = nat;
|
||||
type return = (list (operation), storage);
|
||||
|
||||
let main = ((parameter, store): (nat, storage)) : return => {
|
||||
(([] : list (operation)), parameter);
|
||||
};
|
||||
let main = ((action, store): (parameter, storage)) : return =>
|
||||
(([] : list (operation)), store);
|
||||
```
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -107,8 +112,8 @@ contract, either the counter or the name is updated.
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo group=b
|
||||
type parameter is
|
||||
Entrypoint_A of nat
|
||||
| Entrypoint_B of string
|
||||
Action_A of nat
|
||||
| Action_B of string
|
||||
|
||||
type storage is record [
|
||||
counter : nat;
|
||||
@ -117,24 +122,24 @@ type storage is record [
|
||||
|
||||
type return is list (operation) * storage
|
||||
|
||||
function handle_A (const n : nat; const store : storage) : return is
|
||||
function entry_A (const n : nat; const store : storage) : return is
|
||||
((nil : list (operation)), store with record [counter = n])
|
||||
|
||||
function handle_B (const s : string; const store : storage) : return is
|
||||
function entry_B (const s : string; const store : storage) : return is
|
||||
((nil : list (operation)), store with record [name = s])
|
||||
|
||||
function main (const param : parameter; const store : storage): return is
|
||||
case param of
|
||||
Entrypoint_A (n) -> handle_A (n, store)
|
||||
| Entrypoint_B (s) -> handle_B (s, store)
|
||||
function access (const action : parameter; const store : storage): return is
|
||||
case action of
|
||||
Action_A (n) -> entry_A (n, store)
|
||||
| Action_B (s) -> entry_B (s, store)
|
||||
end
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo group=b
|
||||
type parameter =
|
||||
Entrypoint_A of nat
|
||||
| Entrypoint_B of string
|
||||
Action_A of nat
|
||||
| Action_B of string
|
||||
|
||||
type storage = {
|
||||
counter : nat;
|
||||
@ -143,23 +148,23 @@ type storage = {
|
||||
|
||||
type return = operation list * storage
|
||||
|
||||
let handle_A (n, store : nat * storage) : return =
|
||||
let entry_A (n, store : nat * storage) : return =
|
||||
([] : operation list), {store with counter = n}
|
||||
|
||||
let handle_B (s, store : string * storage) : return =
|
||||
let entry_B (s, store : string * storage) : return =
|
||||
([] : operation list), {store with name = s}
|
||||
|
||||
let main (param, store: parameter * storage) : return =
|
||||
match param with
|
||||
Entrypoint_A n -> handle_A (n, store)
|
||||
| Entrypoint_B s -> handle_B (s, store)
|
||||
let access (action, store: parameter * storage) : return =
|
||||
match action with
|
||||
Action_A n -> entry_A (n, store)
|
||||
| Action_B s -> entry_B (s, store)
|
||||
```
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=b
|
||||
type parameter =
|
||||
| Entrypoint_A (nat)
|
||||
| Entrypoint_B (string);
|
||||
| Action_A (nat)
|
||||
| Action_B (string);
|
||||
|
||||
type storage = {
|
||||
counter : nat,
|
||||
@ -168,18 +173,17 @@ type storage = {
|
||||
|
||||
type return = (list (operation), storage);
|
||||
|
||||
let handle_A = ((n, store): (nat, storage)) : return => {
|
||||
(([] : list (operation)), {...store, counter : n}); };
|
||||
let entry_A = ((n, store): (nat, storage)) : return =>
|
||||
(([] : list (operation)), {...store, counter : n});
|
||||
|
||||
let handle_B = ((s, store): (string, storage)) : return => {
|
||||
(([] : list (operation)), {...store, name : s}); };
|
||||
let entry_B = ((s, store): (string, storage)) : return =>
|
||||
(([] : list (operation)), {...store, name : s});
|
||||
|
||||
let main = ((param, store): (parameter, storage)) : return => {
|
||||
switch (param) {
|
||||
| Entrypoint_A (n) => handle_A ((n, store))
|
||||
| Entrypoint_B (s) => handle_B ((s, store))
|
||||
}
|
||||
};
|
||||
let access = ((action, store): (parameter, storage)) : return =>
|
||||
switch (action) {
|
||||
| Action_A (n) => entry_A ((n, store))
|
||||
| Action_B (s) => entry_B ((s, store))
|
||||
};
|
||||
```
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -203,7 +207,7 @@ type parameter is unit
|
||||
type storage is unit
|
||||
type return is list (operation) * storage
|
||||
|
||||
function deny (const param : parameter; const store : storage) : return is
|
||||
function deny (const action : parameter; const store : storage) : return is
|
||||
if amount > 0mutez then
|
||||
(failwith ("This contract does not accept tokens.") : return)
|
||||
else ((nil : list (operation)), store)
|
||||
@ -215,7 +219,7 @@ type parameter = unit
|
||||
type storage = unit
|
||||
type return = operation list * storage
|
||||
|
||||
let deny (param, store : parameter * storage) : return =
|
||||
let deny (action, store : parameter * storage) : return =
|
||||
if amount > 0mutez then
|
||||
(failwith "This contract does not accept tokens.": return)
|
||||
else (([] : operation list), store)
|
||||
@ -227,7 +231,7 @@ type parameter = unit;
|
||||
type storage = unit;
|
||||
type return = (list (operation), storage);
|
||||
|
||||
let deny = ((param, store): (parameter, storage)) : return => {
|
||||
let deny = ((action, store): (parameter, storage)) : return => {
|
||||
if (amount > 0mutez) {
|
||||
(failwith("This contract does not accept tokens."): return); }
|
||||
else { (([] : list (operation)), store); };
|
||||
@ -245,7 +249,7 @@ This example shows how `sender` or `source` can be used to deny access to an ent
|
||||
```pascaligo group=c
|
||||
const owner : address = ("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx": address);
|
||||
|
||||
function filter (const param : parameter; const store : storage) : return is
|
||||
function filter (const action : parameter; const store : storage) : return is
|
||||
if source =/= owner then (failwith ("Access denied.") : return)
|
||||
else ((nil : list(operation)), store)
|
||||
```
|
||||
@ -254,7 +258,7 @@ function filter (const param : parameter; const store : storage) : return is
|
||||
```cameligo group=c
|
||||
let owner : address = ("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx": address)
|
||||
|
||||
let filter (param, store: parameter * storage) : return =
|
||||
let filter (action, store: parameter * storage) : return =
|
||||
if source <> owner then (failwith "Access denied." : return)
|
||||
else (([] : operation list), store)
|
||||
```
|
||||
@ -263,7 +267,7 @@ let filter (param, store: parameter * storage) : return =
|
||||
```reasonligo group=c
|
||||
let owner : address = ("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx": address);
|
||||
|
||||
let main = ((param, store): (parameter, storage)) : storage => {
|
||||
let access = ((action, store): (parameter, storage)) : storage => {
|
||||
if (source != owner) { (failwith ("Access denied.") : return); }
|
||||
else { (([] : list (operation)), store); };
|
||||
};
|
||||
@ -289,10 +293,10 @@ emiting a transaction operation at the end of an entrypoint.
|
||||
> account (tz1, ...): all you have to do is use a unit value as the
|
||||
> parameter of the smart contract.
|
||||
|
||||
In our case, we have a `counter.ligo` contract that accepts a
|
||||
parameter of type `action`, and we have a `proxy.ligo` contract that
|
||||
accepts the same parameter type, and forwards the call to the deployed
|
||||
counter contract.
|
||||
In our case, we have a `counter.ligo` contract that accepts an action
|
||||
of type `parameter`, and we have a `proxy.ligo` contract that accepts
|
||||
the same parameter type, and forwards the call to the deployed counter
|
||||
contract.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -323,13 +327,13 @@ type return is list (operation) * storage
|
||||
|
||||
const dest : address = ("KT19wgxcuXG9VH4Af5Tpm1vqEKdaMFpznXT3" : address)
|
||||
|
||||
function proxy (const param : parameter; const store : storage): return is
|
||||
function proxy (const action : parameter; const store : storage): return is
|
||||
block {
|
||||
const counter : contract (parameter) = get_contract (dest);
|
||||
(* Reuse the parameter in the subsequent
|
||||
transaction or use another one, `mock_param`. *)
|
||||
const mock_param : parameter = Increment (5n);
|
||||
const op : operation = transaction (param, 0mutez, counter);
|
||||
const op : operation = transaction (action, 0mutez, counter);
|
||||
const ops : list (operation) = list [op]
|
||||
} with (ops, store)
|
||||
```
|
||||
@ -338,7 +342,7 @@ function proxy (const param : parameter; const store : storage): return is
|
||||
```cameligo skip
|
||||
// counter.mligo
|
||||
|
||||
type paramater =
|
||||
type parameter =
|
||||
Increment of nat
|
||||
| Decrement of nat
|
||||
| Reset
|
||||
@ -360,12 +364,12 @@ type return = operation list * storage
|
||||
|
||||
let dest : address = ("KT19wgxcuXG9VH4Af5Tpm1vqEKdaMFpznXT3" : address)
|
||||
|
||||
let proxy (param, store : parameter * storage) : return =
|
||||
let proxy (action, store : parameter * storage) : return =
|
||||
let counter : parameter contract = Operation.get_contract dest in
|
||||
(* Reuse the parameter in the subsequent
|
||||
transaction or use another one, `mock_param`. *)
|
||||
let mock_param : parameter = Increment (5n) in
|
||||
let op : operation = Operation.transaction param 0mutez counter
|
||||
let op : operation = Operation.transaction action 0mutez counter
|
||||
in [op], store
|
||||
```
|
||||
|
||||
@ -395,12 +399,12 @@ type return = (list (operation), storage);
|
||||
|
||||
let dest : address = ("KT19wgxcuXG9VH4Af5Tpm1vqEKdaMFpznXT3" : address);
|
||||
|
||||
let proxy = ((param, store): (parameter, storage)) : return => {
|
||||
let proxy = ((action, store): (parameter, storage)) : return => {
|
||||
let counter : contract (parameter) = Operation.get_contract (dest);
|
||||
(* Reuse the parameter in the subsequent
|
||||
transaction or use another one, `mock_param`. *)
|
||||
let mock_param : parameter = Increment (5n);
|
||||
let op : operation = Operation.transaction (param, 0mutez, counter);
|
||||
let op : operation = Operation.transaction (action, 0mutez, counter);
|
||||
([op], store)
|
||||
};
|
||||
```
|
||||
|
@ -3,13 +3,12 @@ id: include
|
||||
title: Including Other Contracts
|
||||
---
|
||||
|
||||
Lets say we have a contract that's getting a bit too big. If it has a modular
|
||||
structure, you might find it useful to use the `#include` statement to split the
|
||||
contract up over multiple files.
|
||||
Let us say that we have a contract that is getting a too large. If it
|
||||
has a modular structure, you might find it useful to use the
|
||||
`#include` statement to split the contract up over multiple files.
|
||||
|
||||
|
||||
You take the code that you want to include and put it in a separate file, for
|
||||
example `included.ligo`:
|
||||
You take the code that you want to include and put it in a separate
|
||||
file, for example `included.ligo`:
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -23,7 +22,6 @@ const foo : int = 144
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo
|
||||
|
||||
// Demonstrate CameLIGO inclusion statements, see includer.mligo
|
||||
|
||||
let foo : int = 144
|
||||
@ -31,7 +29,6 @@ let foo : int = 144
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo
|
||||
|
||||
// Demonstrate ReasonLIGO inclusion statements, see includer.religo
|
||||
|
||||
let foo : int = 144;
|
||||
@ -46,7 +43,6 @@ And then you can include this code using the `#include` statement like so:
|
||||
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo
|
||||
|
||||
#include "included.ligo"
|
||||
|
||||
const bar : int = foo
|
||||
@ -54,7 +50,6 @@ const bar : int = foo
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo
|
||||
|
||||
#include "included.mligo"
|
||||
|
||||
let bar : int = foo
|
||||
@ -62,7 +57,6 @@ let bar : int = foo
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo
|
||||
|
||||
#include "included.religo"
|
||||
|
||||
let bar : int = foo;
|
||||
|
@ -33,10 +33,10 @@ let today : timestamp = Current.time;
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
> When running code with ligo CLI, the option
|
||||
> When running code, the LIGO CLI option
|
||||
> `--predecessor-timestamp` allows you to control what `now` returns.
|
||||
|
||||
### Timestamp Arithmetic
|
||||
### Timestamp Arithmetics
|
||||
|
||||
In LIGO, timestamps can be added to integers, allowing you to set time
|
||||
constraints on your smart contracts. Consider the following scenarios.
|
||||
@ -124,9 +124,9 @@ let not_tomorrow : bool = (Current.time == in_24_hrs);
|
||||
|
||||
## Addresses
|
||||
|
||||
The type `address` in LIGO denotes Tezos addresses (tz1, tz2, tz3,
|
||||
The `address` type in LIGO denotes Tezos addresses (tz1, tz2, tz3,
|
||||
KT1, ...). Currently, addresses are created by casting a string to the
|
||||
type `address`. Beware of failures if the address is invalid. Consider
|
||||
`address` type. Beware of failures if the address is invalid. Consider
|
||||
the following examples.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
@ -162,7 +162,7 @@ not worry if it is a little confusing at first; we will explain all
|
||||
the syntax in the upcoming sections of the documentation.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--Pascaligo-->
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo group=a
|
||||
type storage is int
|
||||
|
||||
|
@ -148,6 +148,29 @@ gitlab-pages/docs/language-basics/boolean-if-else/cond.ligo compare 21n'
|
||||
# Outputs: Large (Unit)
|
||||
```
|
||||
|
||||
When the branches of the conditional are not a single expression, as
|
||||
above, we need a block:
|
||||
|
||||
```pascaligo skip
|
||||
if x < y then
|
||||
block {
|
||||
const z : nat = x;
|
||||
x := y; y := z
|
||||
}
|
||||
else skip;
|
||||
```
|
||||
|
||||
As an exception to the rule, the blocks in a conditional branch do not
|
||||
need to be introduced by the keywor `block`, so, we could have written
|
||||
instead:
|
||||
```pascaligo skip
|
||||
if x < y then {
|
||||
const z : nat = x;
|
||||
x := y; y := z
|
||||
}
|
||||
else skip;
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo group=e
|
||||
type magnitude = Small | Large // See variant types.
|
||||
|
@ -3,8 +3,8 @@ id: functions
|
||||
title: Functions
|
||||
---
|
||||
|
||||
LIGO features functions are the basic building block of contracts. For
|
||||
example, entrypoints are functions.
|
||||
LIGO functions are the basic building block of contracts. For example,
|
||||
entrypoints are functions.
|
||||
|
||||
## Declaring Functions
|
||||
|
||||
@ -119,8 +119,8 @@ parameter, we should gather the arguments in a
|
||||
[tuple](language-basics/sets-lists-tuples.md) and pass the tuple in as
|
||||
a single parameter.
|
||||
|
||||
Here is how you define a basic function that accepts two `ints` and
|
||||
returns an `int` as well:
|
||||
Here is how you define a basic function that accepts two integers and
|
||||
returns an integer as well:
|
||||
|
||||
```cameligo group=b
|
||||
let add (a, b : int * int) : int = a + b // Uncurried
|
||||
@ -137,10 +137,11 @@ ligo run-function gitlab-pages/docs/language-basics/src/functions/curry.mligo in
|
||||
|
||||
The function body is a single expression, whose value is returned.
|
||||
|
||||
<!--ReasonLIGO--> Functions in ReasonLIGO are defined using the `let`
|
||||
keyword, like other values. The difference is that a tuple of
|
||||
parameters is provided after the value name, with its type, then
|
||||
followed by the return type.
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
Functions in ReasonLIGO are defined using the `let` keyword, like
|
||||
other values. The difference is that a tuple of parameters is provided
|
||||
after the value name, with its type, then followed by the return type.
|
||||
|
||||
Here is how you define a basic function that sums two integers:
|
||||
```reasonligo group=b
|
||||
@ -154,7 +155,19 @@ ligo run-function gitlab-pages/docs/language-basics/src/functions/blockless.reli
|
||||
# Outputs: 3
|
||||
```
|
||||
|
||||
The function body is a single expression, whose value is returned.
|
||||
As in CameLIGO and with blockless functions in PascaLIGO, the function
|
||||
body is a single expression, whose value is returned.
|
||||
|
||||
If the body contains more than a single expression, you use block
|
||||
between braces:
|
||||
```reasonligo group=b
|
||||
let myFun = ((x, y) : (int, int)) : int => {
|
||||
let doubleX = x + x;
|
||||
let doubleY = y + y;
|
||||
doubleX + doubleY
|
||||
};
|
||||
```
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
## Anonymous functions (a.k.a. lambdas)
|
||||
@ -170,7 +183,6 @@ Here is how to define an anonymous function:
|
||||
```pascaligo group=c
|
||||
function increment (const b : int) : int is
|
||||
(function (const a : int) : int is a + 1) (b)
|
||||
|
||||
const a : int = increment (1); // a = 2
|
||||
```
|
||||
|
||||
@ -196,7 +208,7 @@ ligo evaluate-value gitlab-pages/docs/language-basics/src/functions/anon.mligo a
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=c
|
||||
let increment = (b : int) : int => ((a : int) : int => a + 1)(b);
|
||||
let increment = (b : int) : int => ((a : int) : int => a + 1) (b);
|
||||
let a : int = increment (1); // a == 2
|
||||
```
|
||||
|
||||
@ -257,5 +269,4 @@ gitlab-pages/docs/language-basics/src/functions/incr_map.religo incr_map
|
||||
# Outputs: [ 2 ; 3 ; 4 ]
|
||||
```
|
||||
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
@ -20,16 +20,15 @@ loops fails to become true, the execution will run out of gas and stop
|
||||
with a failure anyway.
|
||||
|
||||
Here is how to compute the greatest common divisors of two natural
|
||||
number by means of Euclid's algorithm:
|
||||
numbers by means of Euclid's algorithm:
|
||||
|
||||
```pascaligo group=a
|
||||
function gcd (var x : nat; var y : nat) : nat is
|
||||
block {
|
||||
if x < y then
|
||||
block {
|
||||
const z : nat = x;
|
||||
x := y; y := z
|
||||
}
|
||||
if x < y then {
|
||||
const z : nat = x;
|
||||
x := y; y := z
|
||||
}
|
||||
else skip;
|
||||
var r : nat := 0n;
|
||||
while y =/= 0n block {
|
||||
@ -55,18 +54,19 @@ constant, therefore it makes no sense in CameLIGO to feature loops,
|
||||
which we understand as syntactic constructs where the state of a
|
||||
stopping condition is mutated, as with "while" loops in PascaLIGO.
|
||||
|
||||
Instead, CameLIGO features a *fold operation* as a predefined function
|
||||
named `Loop.fold_while`. It takes an initial value of a certain type,
|
||||
called an *accumulator*, and repeatedly calls a given function, called
|
||||
*iterated function*, that takes that accumulator and returns the next
|
||||
value of the accumulator, until a condition is met and the fold stops
|
||||
with the final value of the accumulator. The iterated function needs
|
||||
to have a special type: if the type of the accumulator is `t`, then it
|
||||
must have the type `bool * t` (not simply `t`). It is the boolean
|
||||
value that denotes whether the stopping condition has been reached.
|
||||
Instead, CameLIGO implements a *folded operation* by means of a
|
||||
predefined function named `Loop.fold_while`. It takes an initial value
|
||||
of a certain type, called an *accumulator*, and repeatedly calls a
|
||||
given function, called *folded function*, that takes that
|
||||
accumulator and returns the next value of the accumulator, until a
|
||||
condition is met and the fold stops with the final value of the
|
||||
accumulator. The iterated function needs to have a special type: if
|
||||
the type of the accumulator is `t`, then it must have the type `bool *
|
||||
t` (not simply `t`). It is the boolean value that denotes whether the
|
||||
stopping condition has been reached.
|
||||
|
||||
Here is how to compute the greatest common divisors of two natural
|
||||
number by means of Euclid's algorithm:
|
||||
numbers by means of Euclid's algorithm:
|
||||
|
||||
```cameligo group=a
|
||||
let iter (x,y : nat * nat) : bool * (nat * nat) =
|
||||
@ -117,7 +117,7 @@ accumulator is `t`, then it must have the type `bool * t` (not simply
|
||||
condition has been reached.
|
||||
|
||||
Here is how to compute the greatest common divisors of two natural
|
||||
number by means of Euclid's algorithm:
|
||||
numbers by means of Euclid's algorithm:
|
||||
|
||||
```reasonligo group=a
|
||||
let iter = ((x,y) : (nat, nat)) : (bool, (nat, nat)) =>
|
||||
@ -149,11 +149,10 @@ let gcd = ((x,y) : (nat, nat)) : nat => {
|
||||
|
||||
In addition to general loops, PascaLIGO features a specialised kind of
|
||||
*loop to iterate over bounded intervals*. These loops are familiarly
|
||||
known as "for loops" and they have the form `for <variable assignment> to
|
||||
<upper bound> <block>`, which is familiar for programmers of
|
||||
imperative languages.
|
||||
known as "for loops" and they have the form `for <variable assignment>
|
||||
to <upper bound> <block>`, as found in imperative languages.
|
||||
|
||||
Consider how to sum integers from `0` to `n`:
|
||||
Consider how to sum the natural numbers up to `n`:
|
||||
|
||||
```pascaligo group=c
|
||||
function sum (var n : nat) : int is block {
|
||||
@ -177,7 +176,7 @@ gitlab-pages/docs/language-basics/src/loops/sum.ligo sum 7n
|
||||
PascaLIGO "for" loops can also iterate through the contents of a
|
||||
collection, that is, a list, a set or a map. This is done with a loop
|
||||
of the form `for <element var> in <collection type> <collection var>
|
||||
<block>`, where `<collection type` is any of the following keywords:
|
||||
<block>`, where `<collection type>` is any of the following keywords:
|
||||
`list`, `set` or `map`.
|
||||
|
||||
Here is an example where the integers in a list are summed up.
|
||||
@ -202,7 +201,7 @@ gitlab-pages/docs/language-basics/src/loops/collection.ligo sum_list
|
||||
|
||||
Here is an example where the integers in a set are summed up.
|
||||
|
||||
```pascaligo=e
|
||||
```pascaligo group=d
|
||||
function sum_set (var s : set (int)) : int is block {
|
||||
var total : int := 0;
|
||||
for i in set s block {
|
||||
@ -222,9 +221,23 @@ gitlab-pages/docs/language-basics/src/loops/collection.ligo sum_set
|
||||
|
||||
Loops over maps are actually loops over the bindings of the map, that
|
||||
is, a pair key-value noted `key -> value` (or any other
|
||||
variables). Give a map from strings to integers, here is how to sum
|
||||
variables). Given a map from strings to integers, here is how to sum
|
||||
all the integers and concatenate all the strings.
|
||||
|
||||
Here is an example where the keys are concatenated and the values are
|
||||
summed up.
|
||||
|
||||
```pascaligo group=d
|
||||
function sum_map (var m : map (string, int)) : string * int is block {
|
||||
var string_total : string := "";
|
||||
var int_total : int := 0;
|
||||
for key -> value in map m block {
|
||||
string_total := string_total ^ key;
|
||||
int_total := int_total + value
|
||||
}
|
||||
} with (string_total, int_total)
|
||||
```
|
||||
|
||||
You can call the function `sum_map` defined above using the LIGO compiler
|
||||
like so:
|
||||
```shell
|
||||
|
@ -97,7 +97,7 @@ let alice_admin : bool = alice.is_admin
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=a
|
||||
let alice_admin: bool = alice.is_admin;
|
||||
let alice_admin : bool = alice.is_admin;
|
||||
```
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -110,9 +110,7 @@ modified.
|
||||
|
||||
One way to understand the update of record values is the *functional
|
||||
update*. The idea is to have an *expression* whose value is the
|
||||
updated record. The shape of that expression is `<record variable>
|
||||
with <record value>`. The record variable is the record to update and
|
||||
the record value is the update itself.
|
||||
updated record.
|
||||
|
||||
Let us consider defining a function that translates three-dimensional
|
||||
points on a plane.
|
||||
@ -120,6 +118,11 @@ points on a plane.
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the shape of that expression is `<record variable> with
|
||||
<record value>`. The record variable is the record to update and the
|
||||
record value is the update itself.
|
||||
|
||||
```pascaligo group=b
|
||||
type point is record [x : int; y : int; z : int]
|
||||
type vector is record [dx : int; dy : int]
|
||||
@ -174,7 +177,7 @@ xy_translate "({x=2;y=3;z=1}, {dx=3;dy=4})"
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
The syntax for the functional updates of record in ReasonLIGO follows
|
||||
that of OCaml:
|
||||
that of ReasonML:
|
||||
|
||||
```reasonligo group=b
|
||||
type point = {x : int, y : int, z : int};
|
||||
@ -199,7 +202,7 @@ xy_translate "({x:2,y:3,z:1}, {dx:3,dy:4})"
|
||||
You have to understand that `p` has not been changed by the functional
|
||||
update: a nameless new version of it has been created and returned.
|
||||
|
||||
### Imperative Updates
|
||||
### Record Patches
|
||||
|
||||
Another way to understand what it means to update a record value is to
|
||||
make sure that any further reference to the value afterwards will
|
||||
@ -365,12 +368,13 @@ let moves : register =
|
||||
|
||||
### Accessing Map Bindings
|
||||
|
||||
We can use the postfix `[]` operator to read the `move` value
|
||||
associated to a given key (`address` here) in the register. Here is an
|
||||
example:
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, we can use the postfix `[]` operator to read the `move`
|
||||
value associated to a given key (`address` here) in the register. Here
|
||||
is an example:
|
||||
|
||||
```pascaligo group=f
|
||||
const my_balance : option (move) =
|
||||
moves [("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN" : address)]
|
||||
@ -480,10 +484,9 @@ We can update a binding in a map in ReasonLIGO by means of the
|
||||
`Map.update` built-in function:
|
||||
|
||||
```reasonligo group=f
|
||||
let assign = (m : register) : register => {
|
||||
let assign = (m : register) : register =>
|
||||
Map.update
|
||||
(("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN" : address), Some ((4,9)), m)
|
||||
};
|
||||
(("tz1gjaF81ZRRvdzjobyfVNsAeSC6PScjfQwN" : address), Some ((4,9)), m);
|
||||
```
|
||||
|
||||
> Notice the optional value `Some (4,9)` instead of `(4,9)`. If we had
|
||||
@ -521,9 +524,8 @@ let delete (key, moves : address * register) : register =
|
||||
In ReasonLIGO, we use the predefined function `Map.remove` as follows:
|
||||
|
||||
```reasonligo group=f
|
||||
let delete = ((key, moves) : (address, register)) : register => {
|
||||
let delete = ((key, moves) : (address, register)) : register =>
|
||||
Map.remove (key, moves);
|
||||
};
|
||||
```
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
@ -540,7 +542,7 @@ There are three kinds of functional iterations over LIGO maps: the
|
||||
*iterated operation*, the *map operation* (not to be confused with the
|
||||
*map data structure*) and the *fold operation*.
|
||||
|
||||
#### Iterated Operation
|
||||
#### Iterated Operation over Maps
|
||||
|
||||
The first, the *iterated operation*, is an iteration over the map with
|
||||
no return value: its only use is to produce side-effects. This can be
|
||||
@ -595,7 +597,7 @@ let iter_op = (m : register) : unit => {
|
||||
```
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
#### Map Operation
|
||||
#### Map Operations over Maps
|
||||
|
||||
We may want to change all the bindings of a map by applying to them a
|
||||
function. This is called a *map operation*, not to be confused with
|
||||
@ -606,7 +608,7 @@ the map data structure.
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the predefined functional iterator implementing the map
|
||||
operation over maps is called `map_map`and is used as follows:
|
||||
operation over maps is called `map_map` and is used as follows:
|
||||
|
||||
```pascaligo group=f
|
||||
function map_op (const m : register) : register is
|
||||
@ -643,9 +645,9 @@ let map_op = (m : register) : register => {
|
||||
```
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
#### Fold Operation
|
||||
#### Folded Operations over Maps
|
||||
|
||||
A *fold operation* is the most general of iterations. The folded
|
||||
A *folded operation* is the most general of iterations. The folded
|
||||
function takes two arguments: an *accumulator* and the structure
|
||||
*element* at hand, with which it then produces a new accumulator. This
|
||||
enables having a partial result that becomes complete when the
|
||||
@ -655,14 +657,15 @@ traversal of the data structure is over.
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the predefined functional iterator implementing the fold
|
||||
operation over maps is called `map_fold` and is used as follows:
|
||||
In PascaLIGO, the predefined functional iterator implementing the
|
||||
folded operation over maps is called `map_fold` and is used as
|
||||
follows:
|
||||
|
||||
```pascaligo group=f
|
||||
function fold_op (const m : register) : int is block {
|
||||
function iterated (const j : int; const cur : address * move) : int is
|
||||
function folded (const j : int; const cur : address * move) : int is
|
||||
j + cur.1.1
|
||||
} with map_fold (iterated, m, 5)
|
||||
} with map_fold (folded, m, 5)
|
||||
```
|
||||
|
||||
> The folded function must be pure, that is, it cannot mutate
|
||||
@ -670,24 +673,26 @@ function fold_op (const m : register) : int is block {
|
||||
|
||||
<!--CameLIGO-->
|
||||
|
||||
In CameLIGO, the predefined functional iterator implementing the fold
|
||||
operation over maps is called `Map.fold` and is used as follows:
|
||||
In CameLIGO, the predefined functional iterator implementing the
|
||||
folded operation over maps is called `Map.fold` and is used as
|
||||
follows:
|
||||
|
||||
```cameligo group=f
|
||||
let fold_op (m : register) : register =
|
||||
let iterated = fun (i,j : int * (address * move)) -> i + j.1.1
|
||||
in Map.fold iterated m 5
|
||||
let folded = fun (i,j : int * (address * move)) -> i + j.1.1
|
||||
in Map.fold folded m 5
|
||||
```
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
In ReasonLIGO, the predefined functional iterator implementing the
|
||||
fold operation over maps is called `Map.fold` and is used as follows:
|
||||
folded operation over maps is called `Map.fold` and is used as
|
||||
follows:
|
||||
|
||||
```reasonligo group=f
|
||||
let fold_op = (m : register) : register => {
|
||||
let iterated = ((i,j): (int, (address, move))) => i + j[1][1];
|
||||
Map.fold (iterated, m, 5);
|
||||
let folded = ((i,j): (int, (address, move))) => i + j[1][1];
|
||||
Map.fold (folded, m, 5);
|
||||
};
|
||||
```
|
||||
|
||||
|
@ -60,13 +60,13 @@ let b : int = 5n + 10
|
||||
let c : tez = 5mutez + 10mutez
|
||||
|
||||
// tez + int or tez + nat is invalid
|
||||
// const d : tez = 5mutez + 10n
|
||||
// let d : tez = 5mutez + 10n
|
||||
|
||||
// two nats yield a nat
|
||||
let e : nat = 5n + 10n
|
||||
|
||||
// nat + int yields an int: invalid
|
||||
// const f : nat = 5n + 10
|
||||
// let f : nat = 5n + 10
|
||||
|
||||
let g : int = 1_000_000
|
||||
```
|
||||
@ -136,7 +136,7 @@ let a : int = 5 - 10
|
||||
let b : int = 5n - 2n
|
||||
|
||||
// Therefore the following is invalid
|
||||
// const c : nat = 5n - 2n
|
||||
// let c : nat = 5n - 2n
|
||||
|
||||
let d : tez = 5mutez - 1mutez
|
||||
```
|
||||
@ -167,15 +167,17 @@ You can multiply values of the same type, such as:
|
||||
```pascaligo group=c
|
||||
const a : int = 5 * 5
|
||||
const b : nat = 5n * 5n
|
||||
// You can also multiply `nat` and `tez` in any order
|
||||
const c : tez = 5n * 5mutez;
|
||||
|
||||
// You can also multiply `nat` and `tez`
|
||||
const c : tez = 5n * 5mutez
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo group=c
|
||||
let a : int = 5 * 5
|
||||
let b : nat = 5n * 5n
|
||||
// You can also multiply `nat` and `tez` in any order
|
||||
|
||||
// You can also multiply `nat` and `tez`
|
||||
let c : tez = 5n * 5mutez
|
||||
```
|
||||
|
||||
@ -183,7 +185,8 @@ let c : tez = 5n * 5mutez
|
||||
```reasonligo group=c
|
||||
let a : int = 5 * 5;
|
||||
let b : nat = 5n * 5n;
|
||||
// You can also multiply `nat` and `tez` in any order
|
||||
|
||||
// You can also multiply `nat` and `tez`
|
||||
let c : tez = 5n * 5mutez;
|
||||
```
|
||||
|
||||
|
@ -13,10 +13,10 @@ values, called *components*, can be retrieved by their index
|
||||
(position). Probably the most common tuple is the *pair*. For
|
||||
example, if we were storing coordinates on a two dimensional grid we
|
||||
might use a pair `(x,y)` to store the coordinates `x` and `y`. There
|
||||
is a *specific order*, so `(y,x)` is not equal to `(x,y)`. The number
|
||||
of components is part of the type of a tuple, so, for example, we
|
||||
cannot add an extra component to a pair and obtain a triple of the
|
||||
same type, so, for instance, `(x,y)` has always a different type from
|
||||
is a *specific order*, so `(y,x)` is not equal to `(x,y)` in
|
||||
general. The number of components is part of the type of a tuple, so,
|
||||
for example, we cannot add an extra component to a pair and obtain a
|
||||
triple of the same type: `(x,y)` has always a different type from
|
||||
`(x,y,z)`, whereas `(y,x)` might have the same type as `(x,y)`.
|
||||
|
||||
Like records, tuple components can be of arbitrary types.
|
||||
@ -68,10 +68,10 @@ position in their tuple, which cannot be done in OCaml.
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
Tuple components are one-indexed like so:
|
||||
Tuple components are one-indexed and accessed like so:
|
||||
|
||||
```pascaligo group=tuple
|
||||
const first_name : string = full_name.1;
|
||||
const first_name : string = full_name.1
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
@ -84,7 +84,7 @@ let first_name : string = full_name.0
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
Tuple components are one-indexed like so:
|
||||
Tuple components are one-indexed and accessed like so:
|
||||
|
||||
```reasonligo group=tuple
|
||||
let first_name : string = full_name[1];
|
||||
@ -102,24 +102,27 @@ called the *head*, and the sub-list after the head is called the
|
||||
*tail*. For those familiar with algorithmic data structure, you can
|
||||
think of a list a *stack*, where the top is written on the left.
|
||||
|
||||
> 💡 Lists are useful when returning operations from a smart
|
||||
> contract's entrypoint.
|
||||
> 💡 Lists are needed when returning operations from a smart
|
||||
> contract's access function.
|
||||
|
||||
### Defining Lists
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo group=lists
|
||||
const empty_list : list (int) = nil // Or list []
|
||||
const my_list : list (int) = list [1; 2; 2] // The head is 1
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
```cameligo group=lists
|
||||
let empty_list : int list = []
|
||||
let my_list : int list = [1; 2; 2] // The head is 1
|
||||
```
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=lists
|
||||
let empty_list : list (int) = [];
|
||||
let my_list : list (int) = [1, 2, 2]; // The head is 1
|
||||
```
|
||||
|
||||
@ -128,7 +131,6 @@ let my_list : list (int) = [1, 2, 2]; // The head is 1
|
||||
|
||||
### Adding to Lists
|
||||
|
||||
|
||||
Lists can be augmented by adding an element before the head (or, in
|
||||
terms of stack, by *pushing an element on top*). This operation is
|
||||
usually called *consing* in functional languages.
|
||||
@ -167,12 +169,6 @@ let larger_list : list (int) = [5, ...my_list]; // [5,1,2,2]
|
||||
```
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
> 💡 Lists can be iterated, folded or mapped to different values. You
|
||||
> can find additional examples
|
||||
> [here](https://gitlab.com/ligolang/ligo/tree/dev/src/test/contracts)
|
||||
> and other built-in operators
|
||||
> [here](https://gitlab.com/ligolang/ligo/blob/dev/src/passes/operators/operators.ml#L59)
|
||||
|
||||
### Functional Iteration over Lists
|
||||
|
||||
A *functional iterator* is a function that traverses a data structure
|
||||
@ -180,16 +176,23 @@ and calls in turn a given function over the elements of that structure
|
||||
to compute some value. Another approach is possible in PascaLIGO:
|
||||
*loops* (see the relevant section).
|
||||
|
||||
There are three kinds of functional iterations over LIGO maps: the
|
||||
There are three kinds of functional iterations over LIGO lists: the
|
||||
*iterated operation*, the *map operation* (not to be confused with the
|
||||
*map data structure*) and the *fold operation*.
|
||||
|
||||
#### Iterated Operation
|
||||
> 💡 Lists can be iterated, folded or mapped to different values. You
|
||||
> can find additional examples
|
||||
> [here](https://gitlab.com/ligolang/ligo/tree/dev/src/test/contracts)
|
||||
> and other built-in operators
|
||||
> [here](https://gitlab.com/ligolang/ligo/blob/dev/src/passes/operators/operators.ml#L59)
|
||||
|
||||
The first, the *iterated operation*, is an iteration over the map with
|
||||
no return value: its only use is to produce side-effects. This can be
|
||||
useful if for example you would like to check that each value inside
|
||||
of a map is within a certain range, and fail with an error otherwise.
|
||||
#### Iterated Operation over Lists
|
||||
|
||||
The first, the *iterated operation*, is an iteration over the list
|
||||
with a unit return value. It is useful to enforce certain invariants
|
||||
on the element of a list, or fail. For example you might want to check
|
||||
that each value inside of a list is within a certain range, and fail
|
||||
otherwise.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -244,7 +247,7 @@ let iter_op = (l : list (int)) : unit => {
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
|
||||
#### Map Operation
|
||||
#### Mapped Operation over Lists
|
||||
|
||||
We may want to change all the elements of a given list by applying to
|
||||
them a function. This is called a *map operation*, not to be confused
|
||||
@ -254,8 +257,9 @@ with the map data structure.
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the predefined functional iterator implementing the map
|
||||
operation over lists is called `list_map` and is used as follows:
|
||||
In PascaLIGO, the predefined functional iterator implementing the
|
||||
mapped operation over lists is called `list_map` and is used as
|
||||
follows:
|
||||
|
||||
```pascaligo group=lists
|
||||
function increment (const i : int): int is i + 1
|
||||
@ -264,10 +268,14 @@ function increment (const i : int): int is i + 1
|
||||
const plus_one : list (int) = list_map (increment, larger_list)
|
||||
```
|
||||
|
||||
> The mapped function must be pure, that is, it cannot mutate
|
||||
> variables.
|
||||
|
||||
<!--CameLIGO-->
|
||||
|
||||
In CameLIGO, the predefined functional iterator implementing the map
|
||||
operation over lists is called `List.map` and is used as follows:
|
||||
In CameLIGO, the predefined functional iterator implementing the
|
||||
mapped operation over lists is called `List.map` and is used as
|
||||
follows:
|
||||
|
||||
```cameligo group=lists
|
||||
let increment (i : int) : int = i + 1
|
||||
@ -278,8 +286,9 @@ let plus_one : int list = List.map increment larger_list
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
In ReasonLIGO, the predefined functional iterator implementing the map
|
||||
operation over lists is called `List.map` and is used as follows:
|
||||
In ReasonLIGO, the predefined functional iterator implementing the
|
||||
mapped operation over lists is called `List.map` and is used as
|
||||
follows:
|
||||
|
||||
```reasonligo group=lists
|
||||
let increment = (i : int) : int => i + 1;
|
||||
@ -290,9 +299,9 @@ let plus_one : list (int) = List.map (increment, larger_list);
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
|
||||
#### Fold Operation
|
||||
#### Folded Operation over Lists
|
||||
|
||||
A *fold operation* is the most general of iterations. The folded
|
||||
A *folded operation* is the most general of iterations. The folded
|
||||
function takes two arguments: an *accumulator* and the structure
|
||||
*element* at hand, with which it then produces a new accumulator. This
|
||||
enables having a partial result that becomes complete when the
|
||||
@ -302,12 +311,12 @@ traversal of the data structure is over.
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the predefined functional iterator implementing the fold
|
||||
operation over lists is called `list_fold` and is used as follows:
|
||||
In PascaLIGO, the predefined functional iterator implementing the
|
||||
folded operation over lists is called `list_fold` and is used as
|
||||
follows:
|
||||
|
||||
```pascaligo group=lists
|
||||
function sum (const acc : int; const i : int): int is acc + i
|
||||
|
||||
const sum_of_elements : int = list_fold (sum, my_list, 0)
|
||||
```
|
||||
|
||||
@ -316,7 +325,7 @@ const sum_of_elements : int = list_fold (sum, my_list, 0)
|
||||
|
||||
<!--CameLIGO-->
|
||||
|
||||
In CameLIGO, the predefined functional iterator implementing the fold
|
||||
In CameLIGO, the predefined functional iterator implementing the folded
|
||||
operation over lists is called `List.fold` and is used as follows:
|
||||
|
||||
```cameligo group=lists
|
||||
@ -327,7 +336,8 @@ let sum_of_elements : int = List.fold sum my_list 0
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
In ReasonLIGO, the predefined functional iterator implementing the
|
||||
fold operation over lists is called `List.fold` and is used as follows:
|
||||
folded operation over lists is called `List.fold` and is used as
|
||||
follows:
|
||||
|
||||
```reasonligo group=lists
|
||||
let sum = ((result, i): (int, int)): int => result + i;
|
||||
@ -365,7 +375,7 @@ let my_set : int set = Set.empty
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
In CameLIGO, the empty set is denoted by the predefined value
|
||||
In ReasonLIGO, the empty set is denoted by the predefined value
|
||||
`Set.empty`.
|
||||
|
||||
```reasonligo group=sets
|
||||
@ -469,7 +479,7 @@ let contains_3 : bool = Set.mem (3, my_set);
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
|
||||
### Cardinal
|
||||
### Cardinal of Sets
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -509,7 +519,7 @@ let set_size : nat = Set.size (my_set);
|
||||
|
||||
In PascaLIGO, there are two ways to update a set, that is to add or
|
||||
remove from it. Either we create a new set from the given one, or we
|
||||
modify it in-place. First, let us consider the former way
|
||||
modify it in-place. First, let us consider the former way:
|
||||
|
||||
```pascaligo group=sets
|
||||
const larger_set : set (int) = set_add (4, my_set)
|
||||
@ -568,8 +578,8 @@ to compute some value. Another approach is possible in PascaLIGO:
|
||||
*loops* (see the relevant section).
|
||||
|
||||
There are three kinds of functional iterations over LIGO maps: the
|
||||
*iterated operation*, the *map operation* (not to be confused with the
|
||||
*map data structure*) and the *fold operation*.
|
||||
*iterated operation*, the *mapped operation* (not to be confused with
|
||||
the *map data structure*) and the *folded operation*.
|
||||
|
||||
#### Iterated Operation
|
||||
|
||||
@ -631,18 +641,18 @@ let iter_op = (s : set (int)) : unit => {
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
|
||||
#### Map Operation
|
||||
#### Mapped Operation (NOT IMPLEMENTED YET)
|
||||
|
||||
We may want to change all the elements of a given set by applying to
|
||||
them a function. This is called a *map operation*, not to be confused
|
||||
with the map data structure.
|
||||
them a function. This is called a *mapped operation*, not to be
|
||||
confused with the map data structure.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the predefined functional iterator implementing the map
|
||||
operation over sets is called `set_map` and is used as follows:
|
||||
In PascaLIGO, the predefined functional iterator implementing the
|
||||
mapped operation over sets is called `set_map` and is used as follows:
|
||||
|
||||
```pascaligo skip
|
||||
function increment (const i : int): int is i + 1
|
||||
@ -653,8 +663,8 @@ const plus_one : set (int) = set_map (increment, larger_set)
|
||||
|
||||
<!--CameLIGO-->
|
||||
|
||||
In CameLIGO, the predefined functional iterator implementing the map
|
||||
operation over sets is called `Set.map` and is used as follows:
|
||||
In CameLIGO, the predefined functional iterator implementing the
|
||||
mapped operation over sets is called `Set.map` and is used as follows:
|
||||
|
||||
```cameligo skip
|
||||
let increment (i : int) : int = i + 1
|
||||
@ -663,11 +673,10 @@ let increment (i : int) : int = i + 1
|
||||
let plus_one : int set = Set.map increment larger_set
|
||||
```
|
||||
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
|
||||
In ReasonLIGO, the predefined functional iterator implementing the map
|
||||
operation over sets is called `Set.map` and is used as follows:
|
||||
In ReasonLIGO, the predefined functional iterator implementing the
|
||||
mapped operation over sets is called `Set.map` and is used as follows:
|
||||
|
||||
```reasonligo skip
|
||||
let increment = (i : int) : int => i + 1;
|
||||
@ -678,9 +687,9 @@ let plus_one : set (int) = Set.map (increment, larger_set);
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
#### Fold Operation
|
||||
#### Folded Operation
|
||||
|
||||
A *fold operation* is the most general of iterations. The folded
|
||||
A *folded operation* is the most general of iterations. The folded
|
||||
function takes two arguments: an *accumulator* and the structure
|
||||
*element* at hand, with which it then produces a new accumulator. This
|
||||
enables having a partial result that becomes complete when the
|
||||
@ -690,8 +699,9 @@ traversal of the data structure is over.
|
||||
|
||||
<!--PascaLIGO-->
|
||||
|
||||
In PascaLIGO, the predefined functional iterator implementing the fold
|
||||
operation over sets is called `set_fold` and is used as follows:
|
||||
In PascaLIGO, the predefined functional iterator implementing the
|
||||
folded operation over sets is called `set_fold` and is used as
|
||||
follows:
|
||||
|
||||
```pascaligo group=sets
|
||||
function sum (const acc : int; const i : int): int is acc + i
|
||||
|
@ -27,7 +27,7 @@ let a : string = "Hello Alice";
|
||||
<!--PascaLIGO-->
|
||||
Strings can be concatenated using the `^` operator.
|
||||
|
||||
```pascaligo
|
||||
```pascaligo group=a
|
||||
const name : string = "Alice"
|
||||
const greeting : string = "Hello"
|
||||
const full_greeting : string = greeting ^ " " ^ name
|
||||
@ -35,7 +35,7 @@ const full_greeting : string = greeting ^ " " ^ name
|
||||
<!--CameLIGO-->
|
||||
Strings can be concatenated using the `^` operator.
|
||||
|
||||
```cameligo
|
||||
```cameligo group=a
|
||||
let name : string = "Alice"
|
||||
let greeting : string = "Hello"
|
||||
let full_greeting : string = greeting ^ " " ^ name
|
||||
@ -43,7 +43,7 @@ let full_greeting : string = greeting ^ " " ^ name
|
||||
<!--ReasonLIGO-->
|
||||
Strings can be concatenated using the `++` operator.
|
||||
|
||||
```reasonligo
|
||||
```reasonligo group=a
|
||||
let name : string = "Alice";
|
||||
let greeting : string = "Hello";
|
||||
let full_greeting : string = greeting ++ " " ++ name;
|
||||
@ -57,17 +57,17 @@ Strings can be sliced using a built-in function:
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo
|
||||
```pascaligo group=b
|
||||
const name : string = "Alice"
|
||||
const slice : string = string_slice (0n, 1n, name)
|
||||
```
|
||||
<!--CameLIGO-->
|
||||
```cameligo
|
||||
```cameligo group=b
|
||||
let name : string = "Alice"
|
||||
let slice : string = String.slice 0n 1n name
|
||||
```
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo
|
||||
```reasonligo group=b
|
||||
let name : string = "Alice";
|
||||
let slice : string = String.slice (0n, 1n, name);
|
||||
```
|
||||
@ -81,18 +81,18 @@ The length of a string can be found using a built-in function:
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo
|
||||
```pascaligo group=c
|
||||
const name : string = "Alice"
|
||||
const length : nat = size (name) // length = 5
|
||||
```
|
||||
<!--CameLIGO-->
|
||||
```cameligo
|
||||
```cameligo group=c
|
||||
let name : string = "Alice"
|
||||
let length : nat = String.size name // length = 5
|
||||
```
|
||||
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo
|
||||
```reasonligo group=c
|
||||
let name : string = "Alice";
|
||||
let length : nat = String.size (name); // length == 5
|
||||
```
|
||||
|
@ -10,16 +10,15 @@ functions. This page will tell you about them.
|
||||
## Pack and Unpack
|
||||
|
||||
Michelson provides the `PACK` and `UNPACK` instructions for data
|
||||
serialization. The instruction `PACK` converts Michelson data
|
||||
structures into a binary format, and `UNPACK` reverses that
|
||||
transformation. This functionality can be accessed from within LIGO.
|
||||
serialization. The former converts Michelson data structures into a
|
||||
binary format, and the latter reverses that transformation. This
|
||||
functionality can be accessed from within LIGO.
|
||||
|
||||
> ⚠️ `PACK` and `UNPACK` are Michelson instructions that are intended
|
||||
> to be used by people that really know what they are doing. There are
|
||||
> several risks and failure cases, such as unpacking a lambda from an
|
||||
> untrusted source, and most of which are beyond the scope of this
|
||||
> document. Do not use these functions without doing your homework
|
||||
> first.
|
||||
> untrusted source or casting the result to the wrong type. Do not use
|
||||
> the corresponding LIGO functions without doing your homework first.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
@ -27,7 +26,7 @@ transformation. This functionality can be accessed from within LIGO.
|
||||
```pascaligo group=a
|
||||
function id_string (const p : string) : option (string) is block {
|
||||
const packed : bytes = bytes_pack (p)
|
||||
} with (bytes_unpack (packed): option (string))
|
||||
} with (bytes_unpack (packed) : option (string))
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
@ -77,7 +76,7 @@ let check_hash_key (kh1, k2 : key_hash * key) : bool * key_hash =
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=b
|
||||
let check_hash_key = ((kh1, k2) : (key_hash, key)) : (bool, key_hash) => {
|
||||
let kh2 : key_hash = Crypto.hash_key(k2);
|
||||
let kh2 : key_hash = Crypto.hash_key (k2);
|
||||
if (kh1 == kh2) { (true, kh2); } else { (false, kh2); }
|
||||
};
|
||||
```
|
||||
@ -116,9 +115,8 @@ let check_signature (pk, signed, msg : key * signature * bytes) : bool =
|
||||
<!--ReasonLIGO-->
|
||||
```reasonligo group=c
|
||||
let check_signature =
|
||||
((pk, signed, msg) : (key, signature, bytes)) : bool => {
|
||||
((pk, signed, msg) : (key, signature, bytes)) : bool =>
|
||||
Crypto.check (pk, signed, msg);
|
||||
};
|
||||
```
|
||||
|
||||
<!--END_DOCUSAURUS_CODE_TABS-->
|
||||
@ -129,8 +127,8 @@ Often you want to get the address of the contract being executed. You
|
||||
can do it with `self_address`.
|
||||
|
||||
> ⚠️ Due to limitations in Michelson, `self_address` in a contract is
|
||||
> only allowed at the entrypoint level, that is, at the
|
||||
> top-level. Using it in an embedded function will cause an error.
|
||||
> only allowed at the top-level. Using it in an embedded function will
|
||||
> cause an error.
|
||||
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
|
||||
|
@ -53,13 +53,12 @@ let dog_breed : breed = "Saluki";
|
||||
<!--DOCUSAURUS_CODE_TABS-->
|
||||
<!--PascaLIGO-->
|
||||
```pascaligo group=b
|
||||
// The type accountBalances denotes maps from addresses to tez
|
||||
// The type account_balances denotes maps from addresses to tez
|
||||
|
||||
type account_balances is map (address, tez)
|
||||
|
||||
const ledger : account_balances =
|
||||
map [("tz1KqTpEZ7Yob7QbPE4Hy4Wo8fHG8LhKxZSx" : address) -> 10mutez]
|
||||
|
||||
```
|
||||
|
||||
<!--CameLIGO-->
|
||||
|
@ -69,7 +69,8 @@ or as function parameters.
|
||||
|
||||
function add (const a : int; const b : int) : int is
|
||||
block {
|
||||
var c : int := a + b
|
||||
var c : int := a + 2*b;
|
||||
c := c - b
|
||||
} with c
|
||||
```
|
||||
|
||||
|
@ -4,14 +4,8 @@ title: Origin
|
||||
original_id: origin
|
||||
---
|
||||
|
||||
LIGO is a programming language that aims to provide developers with an
|
||||
uncomplicated and safe way to implement smart contracts. Since it is
|
||||
being implemented for the Tezos blockchain LIGO compiles to Michelson,
|
||||
the native smart contract language of Tezos.
|
||||
LIGO is a programming language that aims to provide developers with an uncomplicated and safe way to implement smart contracts. Since it is being implemented for the Tezos blockchain LIGO compiles to Michelson—the native smart contract language of Tezos.
|
||||
|
||||
> Smart contracts are programs that run within a blockchain network.
|
||||
|
||||
LIGO was meant to be a language for developing Marigold on top of a
|
||||
hacky framework called Meta-Michelson. However, due to the attention
|
||||
received by the Tezos community, LIGO is now a standalone language
|
||||
being developed to support Tezos directly.
|
||||
LIGO was meant to be a language for developing Marigold on top of a hacky framework called Meta-Michelson. However, due to the attention received by the Tezos community, LIGO is now a standalone language being developed to support Tezos directly.
|
@ -4,79 +4,42 @@ title: Philosophy
|
||||
original_id: philosophy
|
||||
---
|
||||
|
||||
To understand LIGO’s design choices it is important to understand its
|
||||
philosophy. We have two main concerns in mind while building LIGO.
|
||||
To understand LIGO’s design choices it’s important to understand its philosophy. We have two main concerns in mind while building LIGO.
|
||||
|
||||
## Safety
|
||||
|
||||
Once a smart contract is deployed, it will likely be impossible to
|
||||
change it. You must get it right on the first try, and LIGO should
|
||||
help as much as possible. There are multiple ways to make LIGO a safer
|
||||
language for smart contracts.
|
||||
Once a smart contract is deployed, it will likely be impossible to change it. You must get it right on the first try, and LIGO should help as much as possible. There are multiple ways to make LIGO a safer language for smart contracts.
|
||||
|
||||
### Automated Testing
|
||||
Automated Testing is the process through which a program runs another program, and checks that this other program behaves correctly.
|
||||
|
||||
Automated Testing is the process through which a program runs another
|
||||
program, and checks that this other program behaves correctly.
|
||||
|
||||
There already is a testing library for LIGO programs written in OCaml
|
||||
that is used to test LIGO itself. Making it accessible to users will
|
||||
greatly improve safety. A way to do so would be to make it accessible
|
||||
from within LIGO.
|
||||
There already is a testing library for LIGO programs written in OCaml that is used to test LIGO itself. Making it accessible to users will greatly improve safety. A way to do so would be to make it accessible from within LIGO.
|
||||
|
||||
### Static Analysis
|
||||
|
||||
Static analysis is the process of having a program analyze another
|
||||
one. For instance, type systems are a kind of static analysis through
|
||||
which it is possible to find lots of bugs. LIGO already has a simple
|
||||
type system, and we plan to make it much stronger.
|
||||
Static analysis is the process of having a program analyze another one.
|
||||
For instance, type systems are a kind of static analysis through which it is possible to find lots of bugs. LIGO already has a simple type system, and we plan to make it much stronger.
|
||||
|
||||
### Conciseness
|
||||
|
||||
Writing less code gives you less room to introduce errors. That is why
|
||||
LIGO encourages writing lean rather than chunky smart contracts.
|
||||
Writing less code gives you less room to introduce errors. That's why LIGO encourages writing lean rather than chunky smart contracts.
|
||||
|
||||
---
|
||||
|
||||
## Ergonomics
|
||||
|
||||
Having an ergonomic product is crucial on multiple levels: Making
|
||||
features easily accessible ensures they will actually get used. Not
|
||||
wasting users time on idiosyncrasies frees more time for making
|
||||
contracts safer or building apps. Keeping users in a Flow state makes
|
||||
it possible to introduce more complex features in the language. There
|
||||
are multiple ways to improve ergonomics.
|
||||
Having an ergonomic product is crucial on multiple levels:
|
||||
Making features easily accessible ensures they’ll actually get used.
|
||||
Not wasting users time on idiosyncrasies frees more time for making contracts safer or building apps.
|
||||
Keeping users in a Flow state makes it possible to introduce more complex features in the language.
|
||||
There are multiple ways to improve ergonomics.
|
||||
|
||||
### The Language
|
||||
LIGO should contain as few surprises as possible. This is usually known as the principle of least surprise.
|
||||
|
||||
LIGO should contain as few surprises as possible. This is usually
|
||||
known as the principle of least surprise.
|
||||
Most programmers who will use LIGO have already spent a lot of time learning to develop in an existing language, with its own set of conventions and expectations. These expectations are often the most important to accommodate. This is why C-style syntaxes are especially popular (e.g. JavaScript), C-style is well known and new languages want to take advantage of that familiarity. Therefore as an extension of the principle of least surprise, LIGO supports more than one syntax. The least surprising language for a new developer is the one that they have already learned how to use. It’s probably not practical to replicate the syntax of every programming language, so LIGO takes the approach of replicating the structure used by languages from a particular paradigm.
|
||||
|
||||
Most programmers who will use LIGO have already spent a lot of time
|
||||
learning to develop in an existing language, with its own set of
|
||||
conventions and expectations. These expectations are often the most
|
||||
important to accommodate. This is why C-style syntaxes are especially
|
||||
popular (e.g. JavaScript), C-style is well known and new languages
|
||||
want to take advantage of that familiarity. Therefore as an extension
|
||||
of the principle of least surprise, LIGO supports more than one
|
||||
syntax. The least surprising language for a new developer is the one
|
||||
that they have already learned how to use. It’s probably not practical
|
||||
to replicate the syntax of every programming language, so LIGO takes
|
||||
the approach of replicating the structure used by languages from a
|
||||
particular paradigm.
|
||||
|
||||
It is packaged in a Docker container, so that no particular
|
||||
installation instructions are required.
|
||||
It is packaged in a Docker container, so that no particular installation instructions are required.
|
||||
|
||||
### Editor Support
|
||||
Without editor support, a lot of manipulations are very cumbersome. Checking for errors, testing, examining code, refactoring code, etc. This is why there is ongoing work on editor support, starting with highlighting and code-folding.
|
||||
|
||||
Without editor support, a lot of manipulations are very
|
||||
cumbersome. Checking for errors, testing, examining code, refactoring
|
||||
code, etc. This is why there is ongoing work on editor support,
|
||||
starting with highlighting and code-folding.
|
||||
|
||||
### Documentation
|
||||
|
||||
Documentation includes a reference of the languages, tutorials, as
|
||||
well as examples and design patterns. We are a long way from
|
||||
there. But having an extensive documentation is part of our goals.
|
||||
### Docs
|
||||
Docs include documentation of the languages, tutorials, as well as examples and design patterns.
|
||||
We’re a long way from there. But having extensive docs is part of our goals.
|
Loading…
Reference in New Issue
Block a user