Complete reference manual for the version 3 of
Scriptol.
This manual applies to Scriptol 3. The manual of Scriptol 2 of the language matches the Scriptol PHP compiler. For
Scriptol compilers prior to 2014, use the Scriptol
1 manual instead.
The language is entirely implemented into the Scriptol to JavaScript compiler.
Home page: http://www.scriptol.org/
The Scriptol programming language may be used with interpreters
and compilers.
A Windows and Unix version exist for each
compilers.
The goal of the Scriptol language is to be simple,
natural and thus to reduce risk of errors. Scriptol means to
"Scriptwriter Oriented Language". It is an universal
language designed to produce dynamic wew pages, scripts and GUI based
applications. It may be a good scripting language for tools that
produce XML documents.
Scriptol may be embedded inside a html page
and is converted to the same page with PHP code, ready for the Net
and fully portable.
The language has been defined according to
seven rules displayed on the scriptol.com site.
Please note that the [ ] symbols included into the syntax of statements are usually not part of the syntax of the language itself and denote an optional item, but for indexing and intervals.
You must install Node.js to run the command line program. It automatically installs after download on Windows. In Linux you have to type this command:
sudo apt-get install nodejs
Or equivalent, depending on the distribution.
To compile the program to JavaScript, the command is:
solj [options] filename
If the file is already compiled, the JS program is directly launched,
else it is compiled first, and if no error is encountered, it is
executed.
While the source has errors, the command "solp
sourcefile" compiles it again. If the source is a HTML page, it
is not executed after compilation.
Options of the compiler:
none: run a scriptol file, compile it if needed. -w: compile code embedded inside a page and make an HTML file. -j: generate a JavaScript file to be included into HTML. -r: forces to run. Compile if needed and invoques the interpreter. -c: recompile the file and all included ones. Don't interpret. -v: displays more messages when running a program. -q: no message after compilation.
These letters may be combined in a single option.
Ex: -be is
equivalent to -b -e
The solj.ini file can set the path of the scriptol.js lib and the extension of HTML generated file. For example:
lib="c:/scriptolj/scriptol.js htmlext=".php"
A Scriptol source is just a text file with commands inside, one
per line.
Examples:
print x * 2 print x + (y / 2)
With the text editor included in the archive, or any other text editor, enter this text:
print "Hello world"
Save it into the hello.sol file.
Click on the "interpreter" or "interpret" command in the "Tools" menu, the "Hello world" sentence will be displayed.
If you are working in a command line windows (called MS-DOS under Windows or console under Unix), just type:
si hello or solp hello
You may also build and run an executable with the commands:
solc -bre hello build hello.exe or hello under Unix
hello run hello.exe or helloYou can work both with the editor and a command-line windows.
No project file is required to build a whole Scriptol
application.
Just as Java or PHP, you can compile an entire
project just by compiling the main source file.
A Scriptol source
must have an "include" statement for each file the content
of which it uses. The compiler calculates the dependancies among all
levels of embedding and solves cross including.
A Scriptol file must have the ".sol" extension, and may be converted into a newer file with either the ".php" or ".cpp" and ".hpp" extensions or binary file with a ".exe" extension under Windows and no extension under Unix.
Sources files may be eithers scripts or applications (or dynamic web pages).
A script source is a list of statements along with definitions of
functions or classes...
A script, a source with statements at
global level, can't holds a "main" function because for the
compilers, the whole script is itself a "main" function.
An application source holds only functions and data declarations. The main file is the source argument of the compilation command, a "main" function must be defined into the main file, this function must be called, as following:
int main()
... statements ...
return 0
main() ...starting the program
The design of the Scriptol language has been made with a rigourous method and not empirically by adding features from time to time, when needed. Seven rules have been defined to lead the design (look at the "seven" page on the site), and nothing has been included into the language that doesn't satisfy all the rules. I decided as first rule that the language must be simple and natural, and the second one is to suppress all causes of errors for the programmer.
Scriptol may be defined as:
Case-sensitivy:
Identifiers:
Numbers:
This depends upon the target language.
Cast:
Object-oriented:
XML oriented:
Reactive programming
For Scriptol code embedded inside HTML compiled to PHP, it should be inserted inside the following tags:
<?sol
... code scriptol ...
?>
Inside theses markers, the last line of a script must be terminated by a semi colon or an end of line (before the ?> symbol).
The simplest way to use a Scriptol script is to call it from a PHP
page, that holds a simple include statement:
Example:
<?php
include_once("count.php");
update("manual.dat");
?>
This example calls a PHP counter inside the count.php file, built from the example.sol file with the command:
sol -w example php count.php > mypage.html
To compile Scriptol code to JavaScript in an HTML page, put it inside these markers:
<scriptol> ... scriptol code ... </scriptol>
If you have installed a server as Apache or Xitami or Windows
Server on your computer, and configured them to recognize the php
extension, your code will be processed as on a the web, once compiled
to PHP.
Otherwise you have to redirect the output of the script
into a html file, "test.html" for example, with two
commands that produce mypage.php, and execute the PHP code:
solp -w mypagephp mypage.php > test.html
A statement is ended by a semi-colon or by the end of the
line.
When a statement exceeds the width of a line, the line is
concatened with the following one providing that it is ended by a
comma, or by an operator. No symbol is required to continue a
statement on the next line.
Multiple statements on a same line are
separated by a semi-colon. This is provided mostly to leave freedom
to programmers, but may be useful if you insert Scriptol code into an
html page and the editor concatenates the lines!
Source comments are destinated to the reader only and are skipped
by the interpreter.
A one line comment start with the // symbol,
the text is skipped up to the end of the line by the compiler.
// this is a full line comment print x // this is a comment at end of line # this is a persistent comment
A multi-lines comment starts with /* and ends with */. The enclosed
text is skipped.
Example:
/*
Inside these markers, anything is ignored by the compiler
*/
The // and /* */ comments are not included in the target code, unlike # comment.
The Scriptol language does not use a symbol for things that are conceptually different .
+ - * / are arithmetic operators you know.
= operator of assignment.
< less than.
> greater than.
<= less or equal.
>= greater or equal.
; is a end of statement terminator.
, is a separator. It separates elements of an initializer, or of a tuple.
: builds an association. It attaches a body to a header, a value
to a key, a method to an object, and so one...
. uses an association. It associates a method call to the object.
.. separates the limits of an interval of two numbers.
-- is also an interval symbol, upper limit beeing not included.
() groups sub-expressions, or parameters of a function.
[] denotes an index or an interval.
? terminates a condition in one-line control structures.
<> not equal
& binary and, or intersection of arrays.
| binary or, or union of arrays.
<< shift left.
>> shift right.
and logical and (on boolean values).
or logical or.
not logical negation.
^ xor.
mod modulo ("%" from C++ is not recognized).
~~ encloses target code to insert directly.
` encloses template, multi-lines text.
# copyright comment.
// one line source comment.
/* */ multi-lines source comment.
Identifiers are names of variables, functions or objects. They
start with a letter, followed by letters, underscores or digits.
They
are not case-sensitive, you can't give same name to two different
objects, one in uppercase and the other in lowercase.
Keywords are
reserved words of the language and are lowercase.
Variables are names associated at memory fields holding scalar values. Primitives are basic variable implemented in the language.
Scriptol's primitives are these:
var dynamic variable, may be assigned anything. number any king of number (up to "double" in C++). int a number rounded to the integer part. 32 bits. natural 64 bits unsigned integer but 0. real a number with decimals. boolean the true or false value. text a string of characters. array an indexed and dynamic list of objects dict an associative list of pairs key:value. var generic element of array or value of dict. react reactive variable. file a file.
Other types have been added to use external C extensions:
byte external C type. cstring used in C++ or Java declarations (converted to char *).
Basic objects have constructors as other objects:
Syntax:
type(value)
Examples:
int("123")
represents the 123 value.
text(10)
represents "10".
Constructors of scalars are mainly used
to convert from a type to another.
text t = "10" int i = int(t)
A text is written: "sometext" or 'sometext'.
In the
first case, symbols inside the string as $ or { have special meanings
when the target language is PHP.
Literals numbers are written:
123 integer (int) 123n natural 123.0 real 0.123 real 1.2e10 real 0xf8 hexadecimal 0b011 binary true/false boolean
A literal text may be enclosed into simple or double quotes.
print "abc$xyz" print 'abc$xyz'
In the first case, this displays a string of these characters: abc
followed by the content of the xyz variable.
In the second case,
this displays this string: abc$xyz.
To insert characters that cannot be directly inserted with the keyboard, the special escape code \ is used, followed by a letter:
\" inserts a double quote \' inserts a single quote \n inserts a newline. \t inserts a tab. \\ inserts the \ character itself.
Multi-lines
A string may be shared on several line when enclosed inside ` markers like in ECMAScript 6.
Example:
x = `
row 1
row 2
`
Line feed may be either direct or escaped:
x = "one\ntwo" ...valid x = "one two" ... not valid x = `one two` ... valid
Inside a PHP-like string some symbols have special meaning at runtime, a $ symbol means for a variable name.
text xyz = "def" text t = "abc$xyz "
The t variable is assigned the characters a,b,c followed by the content of the variable xyz, and thus, t really holds the string: abcdef. It is called string interpolation.
The {} symbols have a special meaning for the PHP target and must be escaped with the \ caracter in a double quotes string.
The recommended syntax is rather:
text t = "abc" + xyz
A string inside simple quotes and prefixed by $ is not interpreted at all.
text t = 'av$er\n'
is displayed as: av$er\n
The declaration of a variable has the form:
type var [ = expression ] int x text t = "demo"
Declaration of several variable at once is allowed in the form:
type name [= value], name [= value], ...
Examples:
int x, y, z int x = 0, y = 0, z
Assigning a tuple is not allowed (this is allowed only with variables already declared)
int x, y = 1, 2 ... not valid
While the following is supported:
text a = "a"
text b = "b"
text c, d
c, d = [a, b]
The const modifier defines a variable whose value can't
change.
Syntax and example:
const type NAME= value const int X = 5 ... you can't assign further to x another value. const text T = "demo"
Constants declared by users are usually uppercase.
Some
predefined constants are keywords of the language:
true matches an expression that is true. false the opposite. zero the 0 value. nil (Not In List) object that doesn't exist inside a sequence. null value of an object while not initialized yet or sign for deletion.
PI is a built-in constant for the pi mathematical value.
Nil means for "not found" or "empty" while null means for "no value" or "declared but not defined".
Nil is not a real value but a contruction of the language instead. In reading, it reflects the fact that an object is not found by a search in a list. In writing it has the effect of removing an element or a range from a list. A variable can not be initialized with nil.
Examples of use:
array a = [1,2,3,4,5] a[1..3] = nil
Now the content of the array is [1,5].
int i = "demo".find("x")
if i = nil print "Not found"
Since "x" is not in the string "demo", the message "Not found" is displayed.
Here are the values that nil matches for each type...
boolean false
int 0
natural -1
real 0
text ""
array []
dict {}
file null
dir null
object null
var as each of above according to the type of the content.
When Scriptol generates PHP code, nil is replaced by false for numbers, "" for text.
When JavaScript is generated, nil is replaced by -1 for numbers, "" for text.
The null keyword is converted to "null" in PHP, "NULL"
in C++ and "undefined" in JavaScript.
If null is assigned to a variable, the variable can't be
referenced, thus is unusable until it is assigned with a value. You
can only compare it in a condition with the null keyword.
Example of use:
text a = null
The "a" variable may be assigned but otherwise referenced only to be compared to null, or an error message is displayed.
The syntax of a simple assignment is:
identifier = expression
You must assign a variable with a value of same type.
int i = 10 int j = "343" ... bad
It is possible to convert a type into another with constructors of primitives.
When a operation performed on a variable, and the result assigned to the same variable, this may simplified in a simple, augmented instruction.
The syntax of such a compound assignment is:
identifier compound-operator expression
For example, to add 10 to x, and put the result into x, rather than write x = x + 10, you can write x + 10.
Compound operators are: + - * / mod << >> | &
^
Example:
a = 1 ... gives a the value 1
a + 1 ... adds 1 to a
x * y ... replace the content of x by x * y.
a * (x + 2) ... a is multiplied by the expression
a = a * (x + 2) ... as above
a & b ... replace the content of the array a by the intersection of a and b.Takes not in an expression, x + 10 return the addition of x and 10, with no change in x.
if x + 1 : ... x is unchanged.
A tuple of variables may be assigned a tuple of
expressions.
Syntax and example:
name [, name]* = expression [, expression]* x, y, z = 1, x2, 8
The number of expressions at right must match the number of targets
at left or may be a single value assigned to several
variables.
Multiple assignment allows a function to return several
values.
Examples:
x, y, z = 0 a, b = myfunc()
Unlike multiple declaration, multiple assignment may be operated on
variable having different type.
Example:
int x text t x, t = 1000, "abc"
Arrays having a dynamic size, the number of expression to assign is not fixed. Example:
x, y, z = array(1, 2, 3, 4)
Is as: x = 1, y = 2, z = 3.
x, y, z = array(1)
Is as: x = 1
You may assign several variables, previously declared , separated
by commas from:
- a value or expression.
- an array.
-
values of a dict (use the values() method).
- a call of
function.
- a tuple of values or expressions separated by
commas.
In case of array or dict, or a tuple, or a function
returning several values, the variables from 1 to n are assigned the
items from 1 to n, in the same order.
If the number doesn't
match, it is an error.
If the function returns a single value, the
same value is assigned to each variable at left.
Several variables may be assigned at once from several others, or the same variables in a different order. Example:
var a = "alpha" var b = "beta" a,b = [b, a] print a, b
It will display: beta, alpha.
The example actually shows how to swap the contents of two variables, but it also works by assigning different variables. In fact we created an array from two variables and assigned two other variables to its content.
Comparison operators are:
= (equal) < (less than) > (greater than) <= (less or equal) >= (more or equal) <> (not equal)
The "in" operator tests the inclusion of an element in a sequence: a string in a text, an object in an array, a value in a range.
if "a" in line print "in text" if x in 1..10 print "in range"
Binary operators are:
& (and) | (or) ^ (exclusive or) ~ (not) << (shift left) >> (shift right).
Array operators are:
& (intersection) | (union) ^ (complement of intersection).
Precedence
Unary operator have precedence over binary ones. Among binary operators, precedence must be denoted by parenthesis.
An expression is a combination of values and operators. Main kinds
of expressions are:
- Arithmetical expressions: Combinations
of arithmetical values or function calls with these operators: + - *
/ mod.
mod is a shortcut for modulo and returns the remainder of
a division...
Example:
print 100 mod 3 ... should display 1 that is the remainder of 100 divided by 3.
- Conditional expression: Set of two at least expressions linked by relational operators, and returning a boolean value.
= equal < less > greater <= less or equal >= greater equal <> different (the operator != is valid also)
- Logical expressions: A combination of boolean values or expressions
(relational or logical ones) and logical operators and, or, not.
The
"and" expression returns true if the two terms are true,
false otherwise.
The "or" expression returns true if one
of the two terms is true, false if the two ones are false.
If we
add the "not" operator on the whole expression, it negates
the final result.
Example:
boolean x = true boolean y = false if x and y print "true"; else print "false" ... should display false not(x or y) ... is false. x and not y ... is true
- Binary expressions: A set of numbers linked by binary operators.
| binary or & binary and ^ exclusive or ~ binary not << shift left, that is equivalent to multiply by 2 >> shift right, that is equivalent to divide by 2
- Text expressions: Operators on text are:
= < > <= >= to compare two texts. + to concatenate two texts. [] indexing, slicing or splicing (see at text chapter). in test if a text is a part or another one.
Example:
text t = "prefix" print t + "suffix" ...should display: prefixsuffix
- List expressions: Operators on lists (array, dict) are:
= < > <= >= <> compare two lists for values. + concatenates two lists (doubloons may result). - removes from a list, element of a second one (but doubloons). [] indexing, slicing or splicing (see at array and dict). in tests if an element is inside a list. & intersection, returns element common to two lists. | union, returns elements of two list without doubloons. ^ complement of intersection.
Some programming languages have instituted precedence rules, so,
when parenthesis are missing, we know the terms involved by each
operator. Meanwhile precedence has been built inside the Scriptol
parser, error message is thrown when parenthesis are missing because
they are required for readability.
The sole case where precedence
is admitted without parenthesis is for unary operators: not, ~
Unary
operator applies always to the term that follows it, and thus to be
applied to an expression, the expression must be enclosed between
parenthesis.
Examples:
if not a and b if not (a and b)
In the first case, the not operator is associated to the "a"
variable.
The second line negates the whole expression in
parenthesis.
In compound assignment the first operator, that
is also a equal operator, applies to the whole expression at right.
A function starts with a header and ends with the "return"
keyword.
The return type is required, and the type of parameters
also. "void" is used if nothing is returned.
Syntax:
type [,type]* identifier( [parameter [, parameter]*] )
... statements ...
return [expression [, expression]*]
int myfunc(int x)
int, boolean myfunc(text t, int i)
Example:
int multiply(int x, int y)
int z
z = x * y
return zThis may be written simply:
int multiply(int x, int y) return x * y
The body is a list of statements, including some "return" if needed. Inside the body of a function you can put any kind of statement, but a high-level declaration (class, enum) or another function. You can put inner return statements.
The ending statement is a return with zero, one, or several
values.
Examples:
return return x return x, y, 5
If the function return several values, it must have also several return types and the return statement has several parameters (in the same order that the return types).
Example:
text, int, int coordinate(int num)
int x = mytable[num].x
int y = mytable[num].y
return "coo", x, yCalling a function:
A call to a function may assign zero, one, or several variables.
myfunc() a = myfunc() a,b,c = myfunc()
When a function has objects as parameters, the name of the parameters are aliases of the original objects, and any change inside the function are made in fact on the original objects.
By default, primitives are copy and other arguments are aliases. It is possible, if required, to use also the original of a variable, rather than a copy: thanks to the "alias" keyword, the compiler knows that this is just another name for the original variable.
Example: void func(number x) x + 1 print x return void funcalias(alias number x) x + 1 print x return number y = 5 func(y) print y ... should display 6 then 5 funcalias(y) print y ... should display 6 then 6.
Assigning a default value allows to omit an argument at the function call. The complete syntax for the heading is:
type [,type]* name(type name [= expression] [, type name [= expression]]* )
Example:
int increment(int x, int y = 1)
x + y
return x
print increment(10, 5) ... should display: 15
print increment(10) ... should display: 11
The default value 1 has been used to replace the missing parameter.
If the interface of a function has several parameters with a
default value, you can't omit one in the call without omitting all
following ones. The parameters can't be not recognized by their
type.
If what you want if to write a function with different
numbers and types of parameters at call, you must use an array or a
dict instead.
Example:
void param(dict parlist)
size = parlist["size"]
name = parlist["name"]
values = parlist["values"]
return
In this example, the variables "size", "name", "values" are global, and they are just assigned by the content of the dict in argument.
A function opens a new scope for all variables declared inside. If
the function is at the global level, all global variables compiled
before the function are visible in the function.
Inside a
function, a variable can't be declared with same name that a global
variable. This rule applies also inside methods of classes.
If the
function is a method of a class, all variables declared in the class
before the function are visible in the function.
Objects declared
in the function are visible in embedded control structures.
Identifiers still in use can't be reused inside embedded blocks too.
It is possible to avoid PHP display errors and warning if the name
of the function in calls is prefixed by the @ symbol.
This is
ignored by the binary compiler.
@myfunct(x, y)
It is often required to pass arguments to a program from the
command line. To do that in Scriptol (as in PHP), use the external
$argv PHP variable.
To mimic the way C++ passes arguments to a
program, declare a function "main", and call it with $argv
(and $argc if needed) as parameter.
int main(int argnum, array arglist)
print argnum, "parameters"
for arg in arglist
print arg
/for
return 0
main($argc, $argv) $argc and $argv are system variables, assigned automatically.
The main function may be declared either as above or without argument:
int main() int main(int, array)
The int return type is mandatory if the source is compiled to binary.
Echo
Echo displays an expression, or a list of expressions separated by commas, without blank space nor line feed at end (as the print statement does).
Syntax: echo expression [, expression]
Example:
x = 5 y = 20 z = 1 echo "values", x, y / 2 echo z
This will be displayed on the screen as this:
values5101
Example:
echo "demo", 5 echo "next"
displays: demo5next
In a such case, a better display is performed with the print statement. Print replace the comma by a blank space, and it adds a newline at end.
Syntax: print expression [, expression]
Example:
print "demo", 5
displays: demo 5
A single print statement, without parameter, sends a line
feed.
Example:
To enter a text, or numbers, from the keyboard, use the input
command.
A text may be displayed before the input is requested.
Example:
text name input name print name
Example:
input "who are you? ", name
The variable to assign must be declared before the input command, it may be a text or any kind of number.
Control structures are:
if if else /if. one-instruction if. composite if. for for /for. one-instruction for. options: in interval, in array. while while let. while /while. while forever. do do until. do /do condition. do case / else / always /do. enum simple enum. dict enum. error error /error. one-instruction error.
For JavaScript only:
to for /to to while /to one-line to for
break and continue are two statements used inside controls structures.
Scriptol has different syntaxes for short control structures in a
single instruction, or complex one with a block of instructions.
A
one-instruction control structure has the form:
keyword expression let statement or keyword expression ? statement or keyword expression statement-starting-with-a-keyword.
"Let" means for "Last statement, Execute and
Terminate". The let element is always the last part of a control
structure and may be the sole one. In this case there is no ending
but the end of line. The sole statement may be any basic statement
and can't be a control structure.
Let is required when the
statement is an assignment or a function call, but is optional when a
keyword follows it.
The "?" symbol is just a shorter
replacement for "let".
A multi-lines control structure has the form:
structure-name expression [:]
... statements ...
/structure-nameThe colon is optional (but if a statement continues the ligne).
Example with separator:
Example:
if a = b : print t ; /if
One-instruction syntax:
if condition ? statement ; else statement
One must read the line as this: is condition true? if yes, action...
The if then else structure can be written in a more succinct form:
if expression ? action1 ; : action2
Examples:
if a = 5 ? break
if a < 5 ? print "less"
else print "more/equal"
if a = 1 ? print "one"; else print "several"Multi-lines syntax:
if boolean-expression [:]
... statements ...
else ...optional
... statements ...
/ifN.B.: The colon is optional after the condition, as the semi-colon after a statement, but is required to concatenate the lines.
Examples:
if (x + y) > 8
print "> 8"
print x
else
print "<= 8"
/if
if x + y) > 8 : print "> 8" ; print x ; else print "<= 8"; /if
The switch case control structure of C++ or Java is not
implemented in Scriptol because it is too weak and useless (in
Scriptol).
It is replaced by a more powerful variant of the if
construct, that can match any type of variable, and various types of
comparisons.
The syntax is:
if not-boolean-expression [:]
operator expression : statements
operator expression : statements
...
else
... statements ...
/if
A not-boolean expression, is an ident, a litteral, or any expression
that doesn't return a boolean value (true or false).
The
structure: "operator expression : statements" is a case
group. There are no "break" keyword after a case group. A
break will causes exiting from the control structure that would
contain the current "if" structure.
Valid operators
are:
=, <, >, <=, >=, !=, <>, in, else.
"else"
here is equivalent to "default" in the switch case of C.
Examples:
if a
= 1: print 1
= 2: print 2
> 2: print ">2"
else
print "<1"
/if
if x
in array(1,2,3): print "first"
in array(4,5,6): print "second"
in array(7,8) : print "third"
else print "other"
/if
The for control structure scans either a range or a sequence and puts each item into a variable.
Syntax of for range:
for variable in start..end [step s] [:]
... statements ...
/for
The start, end, step elements are either identifiers or literals.
-
step is optional, the default value is 1.
- the end value is
included in the range if the range symbol is "..", not is
the symbol is "-".
- the end value may be inferior to
the start one, providing the step is present and holds a negative
value.
The container variable that is assigned each value of the
range, may be declared into the heading, in this case, it is local to
the control structure.
Syntax of for list:
for variable in list-expression [:]
... statements ...
/for
In this case, the content of an expression is scanned and each
item
assigned to the variable. The expression must be an array, a
text or any expression that returns an array or a text.
Examples:
for i in 1..10
print i
/for
for w in myarray
print w
/for
for w in arr1 + (arr2 & arr3[0..5])
print w
/for
for ident in list let basic-statement
Examples:
for w in mylist let print w for x in 10..1 step -1 let print w + 10
The for loop scans an associative array value by value. It is equivalent to for .. of in JavaScript while for .. in in JavaScript scans keys.
for var v in d let print v // display values
But you may also get the key and the value:
for text k, var v in d let print k, ":", v // display keys and values
This works also on a simple array:
array a = (10,20,30) for int index, int val in a print index, ")", val /for
That displays:
1) 10 2) 20 3) 30
The while structure is a conditional loop.
One-instruction syntax:
while expression let instruction
Standard syntaxe:
while expression [:]
... statements ...
/whileExample:
int x = 10
while x < 20
print x
x + 1
/while
A "break" statement exits the loop.
A "continue"
statement skips all that follows and starts a new loop.
This syntax is recommended to avoid the risk of infinite
loops.
The statement that changes the value of the expression that
is the condition of the loop, is moved after the /while marker by the
mean of the "let" statement.
Example:
while x < 10
if (x mod 2) = 0 continue
print x
/while let x + 1
The continue statement jump to the let instruction.
There is not
corresponding code in C or PHP, because a "continue"
statement in C or PHP bypasses following instructions, including "x
+ 1", and leads to a infinit loop.
Simplified syntax of while let:
while condition
...statements...
let incrementingExample of one-statement loops:
while x < 10 let x + 1 while x < 10 : print x; let x + 1
The condition of the while loop may be the "forever" keyword, and we enter an infinite loop, exited by a "break".
The block of statements enclosed inside the do /do tags, is a new scope, and enclosed statements are perfomed first, before a condition is tested, if a condition is given.
General syntax of do:
do
... statements ...
/do [ condition ]And "/do condition" may be shortened in "until".
The block of statements inside do until is performed while the condition is false, and is exited when the condition is true.
Syntax of do until:
do
... statements ...
until expression
do
print x
x + 1
until x = 10
Do case is a powerful pattern-matching control structure. It contains one or several case groups followed by an optional else and an optional always. One case group only is processed, the one the condition of which if first matched. Always is always executed. Else only when no condition is matched.
Syntax of do case:
do
case condition : statements
[ case condition : statements ]
[ else statements ]
[ always statements ]
/do [while expression]
- A condition if followed by a colon or a newline. After the "else"
and "always" keywords optionally.
- Only one case is
performed, or none if no expression is matched.
- The "else"
group is equivalent to "default" in the switch case of C.
-
The "always" group, if present, is performed in any
cases.
- May end with /do, /do forever, /do while expression.
-
When the forever or the while option are used, the construct becomes
a DFA (Deterministic Finite-state Automata). A break may be required
to exit it.
- A "break" must not be used at end of a
case group as in C: it will exit the whole construct, not the case
group!
Examples:
do
case nom = "pussycat": print "it is a cat"
case nom = "flipper": print "it is a dolphin"
case nom = "mobby dick": print "it is a whales"
else
print "another animal"
/do
int state = ON
do
case state = ON: counter + 1
case state = OFF: break
always
state = getState() ` some function
/do while foreverThe automaton loops until the OFF state is encountered (produced by the called function.
The /do ender may be completed by a condition, while or
forever.
Statements while be processes once, and while the
condition is true.
Syntax of do while:
do
... statements ...
/do while boolean-expression
do
print x
x + 1
/do while x < 3
Options
- do ... /do ... inner bloc of statements, with case
groups or no.
- do ... /do while forever ... infinite loop
- do
... /do forever ... infinite loop in a shortened form
infinite
loop requires a break to exit.
Break is the command to exit a loop.
Example using the
"forever" keyword that leads deliberatly into an infinite
loop:
int x = 0
while forever
print x
if x > 100
break
/if
x + 1
/while
When x reaches the 100 value, the break statement skip instructions
beyond /while, and the while structure.
Continue is a command
to skip all statements, from the current position, up to the end of
the structure, and thus to start a new loop.
int x = -1
while x < 20
x + 1
if (x mod 2) = 0 continue
print x
/while
This example displays only the even values of x, because if an odd
value is encountered, the condition x mod 2 is matched and a continue
command is performed.
Note than if incrementing the variable
tested in the while condition is put after the continue statement, it
is skipped also. An infinite loop is prevented thanks to the while
... let syntax.
Enum allows to assign sequentially values of several types to
identifiers.
You can use also equal to assign an integer, for the
automatically generated sequence continue, starting from this
number.
You can also assign to any identifier, a real or a text,
with a colon.
Syntax of enum:
enum
identifier [ : value | = value ]
[ identifier ...]*
/enum
enum
Z,
ONE,
TWO,
THREE
/enumThis assigns 0 to Z, 1 to ONE, and so one and is equivalent to:
const int ZERO = 0 const int ONE = 1 etc... or: enum: Z:0, ONE:1, TWO:2 /enum
More complex example assigning various values and restarting a sequence:
enum
Z : "a0", ... assign a0
ONE : "a1", ... assign a1
THREE, ... assign 0
FOUR : 3.15, ... assign 3.15
FIVE = 5, ... assign 5 and restart the numbering
SIX ... assign 6
/enumExample of the one-line syntax:
enum ZERO, ONE, TWO, THREE
The syntax of an index in a text or array is: [indice].
The
indice must be a simple expression without square brackets embedded
inside. A simple expression is a literal number, an identifier, a
function call, or an arithmetical expression, and must be resolved as
an integer value.
The syntax of a range is:
start .. end
It is enclosed between square bracket to subscript a list:
list-name[start .. end]
Start and end are integer expressions.
The end is part of the
range unless the "-" operator is used instead.
a[0 -- 100] is as a[0 .. 99] a[x -- y] is as a[x .. y-1]
Examples of ranges:
0..10 x..y x * 2 / 4 .. y + 10
You may use range to:
- test if a value is inside a range: if x in
10..100
- scan a range: for x in 1..100
- extract a part of a
list: array b = a[x..y]
- change a part of a list: a[x..y] =
another-list
The start and end value may be omitted when subscripting a list.
Splitting a list, there are three ways:
array a = array(x0, x1, x2, x3, x4, x5, x6, x7, x8)
array b = a[..2]
array c = a[3..5]
array d = a[6..]
Now we have three arrays, with these contents:
b: (x0, x1, x2)
c: (x3, x4, x5)
d: (x6, x7, x8)
Displaying the arrays:
b.display()
c.display()
d.display()
You should see:
array (
[0] => x0
[1] => x1
[2] => x2
)
and so one...
To replace an interval by another list, a simple assignment is
required:
a[3..5] = array("a", "b", "c")
The
content becomes:
(x0, x1, x2, "a", "b", "c",
x6, x7, x8)
With the same syntax, a sub-list may be replaced either by another
list, or by a single value:
a[3..5] = "xyz"
The
original list becomes:
(x0, x1, x2, "xyz", x6, x7, x8)
If we want rather to remove a sub-list from the original array,
we have to declare it "not in list":
a[3..5] = nil
As
we have removed the sub-list 3..5 that is (x3, x4, x5), the content
now becomes:
(x0, x1, x2, x6, x7, x8)
We can test is a
valuer is in a sub-list.
Example:
array a = array("one, "two", "three")
if "two" in a[2..5] print "inside"
A text is a basic objet with methods, that holds a string of
characters. A literal text is a string encloded between simple or
double quotes. When a text is the argument of a function, the
function uses a copy of the text, not an alias on the original
one.
An indice may be negative in slicing or splicing, not in
indexing.
Syntax:
text s creates a text. s = "str" initializes. s = s[i] gets a char. s[i] = s2 replaces a char, s2 should be a one-char text. s = s[i..j] gets a sub-string, from i until j included. s[i..j] = s replaces a sub string. s[i..j] = "" removes a sub string.
A litteral text is a string of character enclosed in simple or double quotes.
The + symbol may be used with texts as with mathematical
expression to concatenate strings.
Example:
text b = "prefix" text a = b + "suffix"
The content of a will be: "prefixsuffix". T
Return Method Function
void cat(text) concatenates another text.
text capitalize() converts the first char to uppercase.
int compare(text) compares lexicographically two texts (ignore case).
returns -1, 0, 1.
text dup(int) returns a text duplicated n times. Ex: "*".dup(10).
void fill(text, int) fills the text with the text argument n times.
int find(text t2) returns the position of text s2 inside the text.
returns "nil" if no found.
(test for x = nil as x <> nil doesn't work in PHP)
int identical(text) compares, doesn't ignore case. Return -1, 0, 1
void insert(int,text)inserts a text at position.
boolean isNumber() return true if the test is a numeric string.
int length() returns the length.
text lower() converts to lowercase.
text lTrim() removes heading controls/blanks.
void replace(ft, rt) replaces each occurence of ft by rt.
void reserve(int) allocates the size to use the text as a buffer.
text rTrim() removes trailing controls/blanks.
array split(sep) splits a text into items separated by sep.
int toInt() converts to integer.
natural toNatural() converts to natural.
real toReal() converts to real.
text toText() converts a literal string to text (for C++).
text trim() removes heading and trailing control codes/blanks.
text upper() converts to uppercase.
text wrap(int size) wordwraps the text.
Are declared with the type "var".
Dynamic variables
have the methods of all other types of primitives but not the methods
of declared classes (see at "extern").
Once a variable
is assigned to a var, a cast is required to assign the content of the
var to a typed variable:
Methods on var:
A sequence is either a static (text) or dynamic, associative list
(array or dict).
List and sequence have same operators, but &
and | that are proper to lists.
Operations on lists are these:
[] : index, slice, or splice. + : merges two sequences. Or push a scalar to a dynamic list. - : removes a sequence from another one, or an item from a dynamic list. = : compares two sequences. in : tests if an object is in a sequence. & : intersects two lists (gives common elements). | : union without doubloons of two lists.
Two types of dynamic lists of objects exist in Scriptol:
array: keys are integer numbers. dict: (dictionary) keys are texts.
An array is a dymamic and indexed list of object or literals.
Dynamic means the size is not predefined nor limited.
An empty array is symbolized by [].
A literal array is a list of expressions separated by commas and enclosed between square brackets. A variable is a valid element.
The array constructor starts with the keyword "array".
Type a.display() to view the content of the a array, this output is displayed:
array( 0 : first 1 : second 2 : last )
The array constructor has the form: array(value, value, etc...)
An
empty initializer is written: array()
A literal array is written:
{ ... values ... } You can define a array by assigning a literal
array or the constructor, or a single value.
Syntax:
array a creates an array. array a = array() creates an empty array array a = [] creates an empty array array a = array(x, y, ...) creates and initializes an array. array a = [x, y, ...] creates and initializes an array. array a = array(8) using the constructor. array a = 3 create an array of one element.
Elements of an array may be any expression *** but boolean ones ***. If you put the true value inside an array PHP will return always true when you use the "in" operator, with any searched value.
An array may be declared without assigning any content, and filled further:
array a
a.push("first")
a.push("second")
a.push("third")Elements are accessed by their position inside the array. Examples:
a[1] = "a" a[2] = "b" for x in a : print x ... should print: a b
Items inside an array are accessed by an integer number.
Syntax:
a[n] reads the item with at position n. a[n] = x replaces the item at n by x. a[n] = nil erases the item at n a = [] clears the whole array. a[n].upper() calls a method on the dynamic element n.
An empty index designate the current item:
a[] reads the item with at current position.
The indice may be any kind of expression, but this expression must not include another array.
a[10 + x / 2] valid. a[10 + b[5]] not valid.
Since arrays may contains any kind of object, and even other arrays, you need for a dynamic variable to get an element unless you know the type of the item to get:
array a = [ x, "two", 3 ] var x = a[1] use var for unknow element at first position text t = a[2] int i = a[3]
When an element is added outside bound, it is just pushed at last
position into the array.
If you assign an element with the
statement:
a[1000] = "x"
In PHP and JavaScript:
array(
0 : one
1 : two
2 : last one
1000: x
)
In C++:
array(
0 : one
1 : two
2 : last one
3: x
)
In PHP, the 1000 indice is just temporary and will differ as soon
that a statement has modified the array.
For compatibility issue,
use a such statement to replace values in an array, not to add them,
this is the way dict only may be filled.
An array may be scanned with an iterator.
One points out the
first element with begin(), or the last one with end(). The currently
pointed out value is accessed by an empty indice: [].
Iterator methods:
begin() points out the first element and returns it.
end() points out the last element and returns it.
inc() moves to the next element.
Returns the value, or nil, beyond the last element.
dec() moves to the previous element. Returns the value or nil.
index() returns the index of the pointed out element.
value() returns the value of the pointed out element.
[] empty indice for the current element.
nil means for "not in list" and is returned by various functions
when no value can be returned.Example of use with the a array:
a.begin() // moves to the first element
while a[] != nil // tests if end of list reached
print a[] // prints the currently pointed out element
a.inc() // moves to next element
/while
In reverse order:
a.end()
while a[] != nil
print a[]
a.dec()
/while
Once the array is created, you can perform various list - or stack - processing...
a.push("item") ...add an element at end of the list
a.unshift("item") ...insert an element at begin of the list
a.pop() ...read and remove the last element
a.shift() ...read and remove the first element
You can both read and remove the elements of an array by successive
such statements:
print a.shift()
An interval is subscripted by a couple of positions.
a[pos..end] the range between "pos" and "end" included. a[..end] from the start to position "end". a[pos..] from position "pos" to the end of array. a[..] gets the whole array (useless) a[pos] = nil removes an item (keys are renumbered). a[pos..end] = nil removes a range of items (here also). a[pos..end]= b replaces a range by an array/item
An item, or a group of items, may be added or removed with the + and - operators.
Example:
array a = array("one", "two")
array b
b = a + array("three", "four") b is now ("one", "two", "three", "four").
b = b - array("one", "four") b is now ("two", "three").Only the + and - arithmetical operators are usable on arrays along with the in operator.
This operator may be used to test if a value is contained inside a list (array, dict or even a text), and to scan the content too.
Syntax and examples:
if variable in array ... some statement ...
for variable in array ... some statement...
if x in a print "inside"
if x in array(1,2,3) print "inside"
for x in a print x
for t in array("one", "two", "three") print tBinary operators on dynamic lists
You may use for dynamic lists (array or dict) the binary operators:
& intersection returns only elements that are parts of both the two lists | union merge two list without doubloons. ^ complement of intersection a = array(1,2,3,4) & array(3,4,5,6) assigns (3, 4) to a. a = array(1,2,3,4) | array(3,4,5,6) assigns (1,2,3,4,5,6) to a.
The map method, which is implemented in JavaScript and PHP allows to successively apply a function to each element of an array and optionally return a new array. example:
int mapfun(int x) return x * 25
b = [1,2,3,4,5]
print b.map(mapfun)
If you want to apply a function to several arrays at once, or dicts, the index is used. Example:
for text k, var v in d1 d1[k] + d2[k] /for
Elements are added one by one, from the contents of the associative array d1 and d2.
Using a function, with two parameters:
array a1 = [1,2,3,4,5]
array a2 = [10, 20, 30, 40, 50]
int mapfun(int x, int y) return x + y
for int i, var x in a1 print mapfun(x, a2[i])
The number of dimensions is not limited.
For a two-dimensional
array, the syntax...
- to access an element is: x =
arrayname[i][j]
- to change an element is: arrayname[i][j] = x
To create an element, the syntax is:
arrayname[i] = array() arrayname[i][j] = x or arrayname[] = array(x)
You cannot create directly an element into a not existing sub-array. The i and j indexes suppose that i and j elements already exist.
The language can make comparisons between arrays of numbers with all relational operators. Two arrays of different sizes are different.
For arrays of strings or other objects, you can test only if they are identical or if they are different. For further comparisons, you must define your own algorithm.
We have to know how integer keys of PHP array change, according to all operations we can perform. This is important to understand associatives arrays and to avoid lot of bugs. After each operation, the content is displayed.
array a = []
array ()
a.push("one")
array
(
[0]=> one
)
a + array("two", "three", "four")
array
(
[0]=> one
[1]=> two
[2]=> three
[3]=> four
)
a.shift() The first element is removed and the keys are renumbered.
array
(
[0]=> two
[1]=> three
[2]=> four
)
a[1000] = "thousand"
array
(
[0]=> two
[1]=> three
[2]=> four
[1000]=> thousand
)
a.unshift("x") All keys are renumbered, even the 1000 one.
array
(
[0]=> x
[1]=> two
[2]=> three
[3]=> four
[4]=> thousand
)
Creating two new arrays:
array a = ["one","two"]
array b = []
b[1000] = "thousand"
a + b
Keys are renumbered.
array
(
[0]=> one
[1]=> two
[2]=> thousand
)If we replace a + b by a.push("thousand") the result will be the same.
Return Name Action var begin() points out the first item. var dec() decrements the pointer and returns the element. void display() displays the array. var end() points out the last item. boolean empty() returns true if array empty. int find(var) searches for an item, returns the index or nil. int findLast(var searches for an item from the end. var inc() increments the pointer and returns the element. int index() returns the index of pointed out item. void insert(int, var) inserts a value at the integer position. text join(text sep) converts into text with sep between elements. boolean load(text name) loads the file into the array. var min() gets the lowest value. var max() gets the highest value.
array map(function) applies a function to each element and returns a new array. void pack() Makes elements of the array consecutives. var pop() gets and removes the last item. var pop(int) gets and removes the item at the given position. void push(var) adds an item at end. var rand() returns an item at random location. list reverse() returns the list in reverse order. var shift() gets and removes the first item. int size() returns the number of elements. void sort(int) sorts the values in ascending order. See below. void rsort(int) sorts the values in descending order. See below. void store(text name) stores the array into a file. Add false as argument to not add eol. number sum() calculates the sum of items. text toText([text]) converts the array to text with glue string in option. array unique() return the array with not doubloons, first found kept. void unShift(var) inserts an item at the first position.
The sort method requires one optional parameter: 0 for an alphabetical sorting (the default in JavaScript and PHP), 1 for numerical sorting.
A dict is a dymamic list of pairs key and value. Keys are always
texts. Values may be any objects. A variable may be used as key or value.
The
format for a pair key and value is:
key:value
An empty dict is symbolized by {}.
A literal dict is a list of pairs separated by commas and enclosed in curly braces.
Unlike arrays, a dict is filled by assignments:
d[k] = "b" d["first"] = "element 1"
Although JavaScript supports digital keys placed in quotation marks, thus considered texts, it produces unpredictable results when mixed with alphabetic keys. Thus mixing these types must be avoided.
A dict may be assigned a constructor or a literal dict.
Syntax:
dict d ... creates a dict.
dict d = {x:v, y:w,...} ... creates and initializes a dict.
dict d = dict(x:v, y:w,...) ... creates and initializes a dict.
The values stored may be any kind of objects.
The key can be a
variable and the value an expression.
Examples:
text k = "a" text v = "b" dict d = dict(k : v) dict d = dict(k : v + "x".dup(4) + 20.toText())
This example puts "bxxxx20" into d with the key "a".
Items in an dict are accessed by a textual key.
Syntax:
d["key"] ...gets the first item with the key "key".
d[key] = var ...replaces a value or add the couple key, value
...if the key is not already inside the dict.
d[key] = nil ...removes an item.
d = {} ...clears the whole dict.
Example:
dict d
d["program"] = "what we want to write faster"
print d["program"] ... will display the text above
The right way to use a dictionary is by the means of keys or
iterator. In some cases, it mays be useful to access a range of items
directly.
When adding an element or another dictionary to a dict,
by the way of interval, push, unshift, PHP generate a new key for the
item. The new key is a number.
- If you replace a range by another
dict, some of the items may be lost.
- This also does happen when
merging.
- The keys of the replacing dict are not kept in changed
dict.
Examples of display:
Should print all keys and values in the
dictionary.
dict d = {"a":"alia", "b":"beatrix", "c":"claudia"}
d.display()
for k,v in d : print k,v; /for
Return Name Action void display([flat]) displays the dict indented. If flat is false, it is not indented. boolean empty() returns true if the dict is empty. int hasKey(text) returns true if the key exists. int find(var) searches for an item, returns the index or nil. int findLast(var) searches from the top. dict getById(text) return a dict with an id property whose value is in parameter. array getByName(text) return an array of all elements having a name attribute whose value is the parameter. array getByTag(text) return an array of all elements whose tag attribute has the parameter as value. array keys() returns the list of keys. void kSort() orders the indices, associations being preserved. void load(text name, [xml]) loads the file into the dict. var pop() gets and removes the last item. var shift() gets and removes the first item. int size() returns the number of elements. void sort() sorts the values in ascending order. void store(text name) stores the dict into a file. text toXML() converts the dict to XML in a string. void unShift(text, var)inserts a pair key value at the first position. array values() returns the list of values.
Method load: The file is converted from XML to dict if the extension is xml, rss, svg or if the optional argument is 1.
Typed arrays hold a unique type of objets. They are very more efficient than common arrays because processing directly 32 bits or 64 bits objects or pointers rather than dynamic variables is faster. (This is for binary executables, there is no difference in a PHP target.) Typed arrays are dynamic also, size is not limited, and boundary overflow is controled.
Virtual methods of typed arrays are identical to that of mixed arrays. See above.
The constructor of a typed array has the form:
type(...elements...) Example: int(1, 2, 3)
The number of element is between 0 and n.
When there is only one element, there is no difference between the constructor of typed array and the constructor of a scalar:
int(1)
text("text")This is not a problem at assignment as we can create an array from a scalar.
The syntax to declare an array of int is:
int[] i = int(x, y, ....)
Once it is declared, it is used as a common mixed array, but only
integer numbers may be added to the array.
At creation stage, a
constructor or a literal may be assigned.
If you use a single argument: int(10), for example, this can be assigned either to a variable or to an array of int. In an expression a such constructor is a scalar. You must use a literal for one-element typed array.
Examples:
int[] x = int(5)
int[] x = int(1,2)
int[] x = y + int{5}
The declaration is:
text[] t = text(a, b, "demo", ...)
The rules of int array apply to text array also and all type of typed array.
The declarations are:
real[] r = real(1.0, 2.0, ...) natural[] n = natural(1, 2, ...) number[] n = number(1, 2.0, ...)
The declaration is:
class Someclass
...
/class
Someclass object1 ... instance
Someclass object2 ... instance
object[] = object(object1, object2, ...) ... array of objects
You can assign a typed array to a mixed array:
int[] i = int(... array a = i
- You can't, of course, assign a mixed array to a typed array since the values may have different types, unless you push the elements one by one. A literal array without prefix is considered to be a mixed array. Thus you can't assign it to a typed array.
Examples:
[1,2,3] ... this is a mixed array even with integer items.
int[] i = [1,2,3] ... NOT VALID you must write instead:
int[] i = int(1,2,3) ... valid.
- You can't create a mixed array with a constructor of typed array:
array a = int(1,2) ... NOT VALID array a = array(int(1,2)) ... NOT VALID
You can assign a typed array to a var.
int[] i = int(1,2) var d = var(i)
Two new var methods are provided to use a such var:
arrayType()
return the type of the typed array assigned to a
var.
toList(int = 0) return a typed array assigned to a var.
The
parameter is the type (see below) and is required only if the var
hold a classical array we want return as a typed one.
Types currently recognized are:
$TYPE_INT array of integers $TYPE_TEXT ... $TYPE_REAL $TYPE_NATURAL $TYPE_NUMBER $TYPE_OBJECT
Example of use:
d = var(int(1,2))
if d.arrayType()
= $TYPE_INT:
int[] i = d.toList()
= $TYPE_TEXT:
text[] t = d.toList()
/if
For compatibility with PHP, adding an element to an array outside
the boundary, has same effect than pushing it on top of the
array.
For example:
int[] i i[10] = 10 ...this is equivalent to: i.push(10)
Pushing values is the right way to fill an array in fact.
If you want really putting element at fixed position, you have to fill the array with some values...
for int k in 0 .. 10 let i.push(0)
you can now put an element at the 10 indice.
- You can't apply a method directly to an element of a typed array.
i[10].toText() .. not valid int x = i[10] x.toText() .. valid
- You can't compare directly an element and a string.
text[] t = text("one", "two")
if t[0] = "one" ... not valid
text t2 = t[0]
if t2 = "one" ... valid- The PHP's array_diff function doesn't work with arrays holding objects, so substracting such arrays is not possible.
File is virtual object, for processing local or distant files.
For
a complete explanation of the file system, see "fopen" in a
C manual. A file object is created by an instance declaration. The
file itself is created by the "open" command. The open
command allows to access a file in different modes, accoding to the
second parameter of the "open" method.
The error control
structure is used to test if the file has been properly opened or
not.
Syntax to create or open a file:
file fname declares a file. fname.open(path, mode) opens the file with the path, and the mode. Path types: http://path http distant file. ftp://path ftp distant file. path local file. Modes: "r" read only. "w" write only. "a" append at end of file, write only. "r+" reads or write at start of file. "a+" reads at current location, or write at end.
File's methods are:
return method action int eof() return true, if end of file reached. int open(text, text) create or open a file. Set the error flag. int close() close the file. text read(int) read a chunk of size in argument, returns a text. text readLine() read the next line from a text file, returns it. int seek(int) go to the position in argument. Return 1 if ok. int size() return the size of the file. int time() return the time of last change. int write(text) write the text in argument, return the size written. void writeLine(text) write the text in argument.
Examples:
file myfile creates a file object.
myfile.open("myfilename", "r") opens a real file.
myfile.close() closes the file.
boolean b = myfile.eof() returns true if end of the file reached.
myfile.seek(250) reads or writes skipping the first 250 bytes.
Distant files are not handled by Scriptol C++ and the interpreter for now.
A file may be read line per line, or by binary blocks.
In the
first case, the readLine() method is used, otherwise the read method
has the size of the block as parameter.
The end of line code is
included in the text and may be removed by the rTrim() text
method.
Examples:
text t = fname.readline() reads a line terminated by a newline code. text t = fname.read(1000) reads a block of 1000 bytes from the file.
The write method puts the content of a text variable inside a
file. Once the file is open (either in "w" or "a"
mode), and thus written either from scratch or at end of the current
content, each new call to the write method results in appending a new
text at end.
Example:
text filename = "myfile"
file outfile name of the virtual object.
outfile.open(filename, "w") opens to write.
error? die("enable to open " + filename) if error, exits with a message;
for text line in outList an array previously filled
outfile.write(line) writes an element
/for
outfile.close() closes the file
Standard XML code can be inserted into a scriptol program. It will be converted into an associative array. Tag within another tag is converted into dict inside another dict.
The textual content of a tag is associated to the data key in the generated associative array.
Example:
<xml id="car" speed=150 name="Spitfire">
<engine id="engine1" power=100 />
<passengers id="pass1" num=4 >
"Clara, Dana, Elisa, Farah"
</passengers>
</xml>
This JavaScript code is generated by the compiler:
var car={
"_00" : "car",
"tag" : "xml",
"speed":150,
"name":"Spitfire",
"engine1":{
"tag": "engine",
"power":100
},
"pass1":{
"tag": "passengers",
"num":4,
"data":"Clara, Dana, Elisa, Farah"
}
};
Or this PHP code:
$car=[ "speed"=>150, "name"=>"Spitfire",
"engine"=>[ "power"=>100 ],
"passengers"=>[ "num"=>4,
"data"=>"Clara, Dana, Elisa, Farah" ] ];
The associative array may also be converted into an XML document in a text variable that may be saved to a file:
car.toXML().store("file.xml")
After the "open" statement, the control structure "error
/error" or one-line "error ?" should be executed to
detect when an access error occurs. But the interpreter may stop the
program before the construct is processed.
Otherwise the body of
the error block is processed when an error occurs.
The syntax is:
xxx.open("filename")
error
...statements...
/error
or:
xxx.open("filename"); error ? action
or:
xxx.open("filename"); error action
Example:
file myfile
myfile.open("filename", "r")
error? exit()
If the file can't be found or opened, the program exits.
Rules of visibility of variable are that of main procedural
language, not that of scripting languages.
Scriptol add some
safety rules, it doesn't allow a same name to be given to different
objects in embedded scopes (for example, the global scope and the one
of a function). But names may be reused in successive scopes.
There are four scoping levels: - global, - class, - body of a function, - and body of a control structure.
The scope of a variable is level where it is declared: global,
class, function or delimited block of statements (body of if, while,
do, case, etc...), and inner levels.
A variable can't be
redeclared inside the same scope, but only when the scope is closed,
inside other scopes.
The header of the for control structure is a part of the body's scope.
for text t in a // t is visible only inside the for loop t = a.inc() /for
The scope of the let statement that ends a while control structure is
a part of the body of the while structure.
Parameters of a function
are inside the scope of the function.
Inside a function, if a
variable is referenced before any assignment, it is assumed
referencing a global variable if it exists, otherwise this is an
error.
Inside a method of a class, if it is referenced before any
assignment, it references to a member if this member exists,
otherwise this is an error. Global variables are not visible inside
classes, but the external ones.
External variables (those of PHP, Apache, etc...) are always in
the scope, since there is no control for them (look at the "External
variable" section).
Thus, you have to know their name to
avoid using a name that will become that of a PHP variable, when the
"$" will be added to.
If you use PHP external variables
inside a function, you must declare them as "global", as
the compiler does not manage them.
Functions, variables and constants of the PHP or C++ languages or
extensions may be used inside the Scriptol code.
Their scope is
external, that means they are visible anywhere, in global, local or
class scopes.
PHP variables and constants may be used as scriptol objects,
providing they are declared with the extern keywords.
Extern
declarations, as include ones, must be put at start of a source file.
The syntax is:
extern type identifier extern const type identifier
No any test is performed on the type and the scope or external, and you must also use a global statement if you use them inside a function.
Example:
global argv array a = $argv
A PHP constant is declared as a variable, with the const modifier.
Example:
extern const text PHP_VERSION
...
print PHP_VERSION
It is possible also to use a PHP or C++ variable without declaration
with the $ prefix followed by an identifier.
It can start with an
underscore.
$var_name $(constant_name)
PHP functions may be used without declaration, this is not the
case for C++ functions.
To declare a external function, a extern
statement is required.
A default value is denoted by an
assignment. The value is used in the C++ target, it is ignored by
PHP.
Syntax and example:
extern type identifier(... parameters...) extern text substr(text, int, int = 0)
To use methods of PHP or C++ classes, you must declare the classes and the members you want to use.
Example:
extern
class phpClass
int phpAttribute
void phpMethod(int parameter)
... declarations ...
/class
/extern
C++ allows to create new types with the typedef and define
directives. These types may be integrated into a Scriptol source with
the "define" instruction:
Example: define uint
This
corresponds to "#define uint unsigned int" in C++.
No
any code is generated by the define instruction: the C++ definition
must existats inside an included C++ header file.
See at "The
define statement" for more on this command.
If you want to insert PHP or C++ code directly into your program,
use the ~~ symbols to enclose the code.
The compiler doesn't
process it, it is as a comment for the Scriptol compiler, but it is
processed by the target interpreter or compiler.
You can include code specifically for the PHP interpreter or C++
compiler.
- If you want to insert some PHP code, use this
statement: require_once("thefile.php") This statement is
interpreted in PHP, but is ignored by the C++ compiler.
- To
insert C++ code, use a such statement: #include "thefile.cpp"
This
is compiled in C++, but for the PHP interpreter this is just a
comment.
A class is a structure which contains variables (attributes) and
has functions (methods).
Once a class is defined, it becomes a new
type added to the language and unlimited number of instances
(objects) may be declared with this new type. We use attributes and
methods of the object with a command in the form:
x = object.attribute object.method()
The description of a class begins with the "class" keyword and ends with "/class".
Example of a class declaration:
class car ...members... /class
Example of class with attributes and methods:
class car
int theSpeed = 50
int passengers = 4
void car.speed(int i)
int x = theSpeed * 2
return x
/class
Example of instance and method reference:
car mycar print mycar.passengers print mycar.speed()
A constructor is a method the name of which being that of the class, and that is called only when creating an instance of the class. The constructor always returns a void type.
Example of constructor:
class Car
int speed
void Car(int p) ` this method is the constructor
speed = 0 ` speed is initialized with a default value
return
/class
The syntax to create an instance is:
Classname instancename =
Classname(parameter [, parameters])
or:
Classname instancename
... for a constructor without parameter.
Example:
Car mycar = Car(60) ... create a car with a speed of 60 Truck mytruck ... is equivalent to Truck mytruck = Truck()
It is convenient to store all functions relative to a task into a class and declare them "static". You can then refer to these methods directly along with the class name without the need for declaring an instance.
Example:
node, ext = Dir.splitExt(path)
Static attributes are also allowed . A static attribut is common to
all instances of the class and inherited ones. Static methods can use
only static attributes, as other ones exist only in instances of the
class, Static methods can't reference other methods.
The "static"
modifier must preceed the type of the object. An error message is
thrown if a static method attemps to use a non-static attribute or to
call another method.
Example of static attributes and methods:
class Car
static factory = "xxx"
static void setName(text x)
factory = x
return
/class
Car.setName("name")
Car.factory = "name"Static attributes and methods may be associated to an instance also:
Car myCar
myCar.setName("name")
myCar.factory = "name"The result will be the same.
A class may inherit from attributes and method of another one, if
it is declared as a subclass of it.
The class "name"
inherits of attributes and methods of the superclass "othername".
This works also for static attributes and methods.
The syntax of inheritance declaring is:
class name is othername
Example:
class Vehicle
int fuel
void Vehicle()
fuel = 100
return
/class
class Car is Vehicle
int passengers
void Car()
passengers = 3
fuel = 50
return
/class
class Truck is Vehicle
int charge
void Truck()
fuel = 200
charge = 1000
return
/class
Truck redbaby
print redbaby.charge attribute of the Truck class
print redbaby.fuel attribute of the Vehicle superclass
print redbaby.passengers bad! passengers is not accessible to Truck!
Car daisy
print daisy.passengers good, passengers is attribute of Car
A method may be redefined with different parameters, both inside the same class or into inherited classes. The return type must be the same for any definition of the method.
Example:
void add(int x, int y) void add(real x, natural y)
You have just to call the "add" method with any arguments,
the compiler associates the corresponding definition...
The main
target language, C++ requires the return type remains the same, and
this has been kept also in Scriptol.
The syntax to include an external scriptol file is:
include "filename.sol"
Parenthesis are optional. Simple or double quotes are required. If
you want to use directly a PHP file, and the compiler not to compile
it, use a PHP extension.
Only files having a ".sol" extension are
parsed by the scriptol compilers. For other extensions:
Examples.
include "example.php" include "example.js
The PHP file will be ignored by the JavaScript code and the JS file will be ignored by the PHP code.
When scriptol code is embedded into an HTML page to be compiled to JavaScript, a file to include must be enclosed in <scriptol> and </scriptol> tags (even if there is only scriptol code in the file. The code generated for an HTML page may be different.
External modules included by npm can be declared as a dictionary or as an object.
In the first case, the module is declared as follows:
const net = require("net")
In the second case, the module must be included to the global scope with the import command:
import MyModule = require("MyModule")
And in the second case, it must be used by an instance:
MyModule module1
In all cases the Scriptol compiler does not check the attributes, methods and arguments. This is delegated to the JavaScript virtual machine.
You can use a function as argument of another function by defining this function as a type. This works only at the global level and can't be used inside a class. Once a type is defined, you can't redefine it.
1) define a function:
Example:
int compare(int a, int b)
boolean b = (a < b)
return b2) use the function type to uses this function as argument:
void myfunc(function a, int x, int y)
print a(x,y)
return
3) use the generic function:
The argument may be the original
function or another function with same arguments and return type.
myfunc(compare2, 10, 8)
The syntax is :
define NEWTYPE define NEWTYPE as
Create
a new type you can use in arguments of external functions. Look at
the GTK examples for how to use the new type.
The "as"
modifier prevents the new type to be used as a pointer. Use as if the
type is a primitive, as uint or gint for example.
These scriptol functions are common to JavaScript, PHP, and C++.
The full list is in the fun.hpp header file.
void die(text) Displays a message and exits the program. void exit() Exits the program. number min(num, num) Returns the lowest of two arguments. number max(num, num) Returns the greatest of two arguments. const cstring plural(int) Returns "s" if the integer is greater than 1. array range(int, int) Generates an array of integers from x to y. cstring str(number) Converts a number into a string of chars. void swap(var, var) Exchanges the content of two variables. text pad(text t, len l , text c[, int o]) Pads a text with blank space or the given string of chars. t: text to pad. l: length to reach. c: char to add, default blank space. o: options STR_PAD_LEFT, STR_PAD_BOTH, default at right.
Casting
text chr(number) Returns the character for an ASCII value, ex "A" for 65. int ord(text) Gets the ASCII value of a character. int intval(any) int doubleval(any) natural naturalval(any) text strval(any) Convert a number to a text. char *str(any) Convert a number to a C string. boolean boolval(int)
File functions (see also at File type methods):
void exec(text) Passes a command to the operating system. bool file_exists(text) Test if the file whose name is in argument, exists. number filesize(text) Return the size. number filetime(text) Return the time (use date function to display). text filetype(text) Return "file" or "dir". boolean rename(text, text) Renames a file. Returns false if impossible. void system(text) Passes a command to the operating system. boolean unlink(text) Deletes a file. Returns true if deleted. var require(text) Declare an external module (JavaScript only).
Directory functions:
boolean chdir(text) Changes the current directory. Returns false if unsuccessful. boolean mkdir(text) Creates a sub-directory, returns true if created. boolean rmdir(text) Deletes a sub-directory. Returns true if deleted. text getcwd() Returns the path of the current directory.
Math functions:
number abs(number) Returns the absolute value of a number. real acos(real) real asin(real) real atan(real) number ceil(number) Returns the rounded up integer. real cos(real) real exp(real) number floor(number) Returns the rounded down integer. number fmod(number, number) Return the modulus of two numbers. real log(real) number pow(number, number) Returns the n power of a number. int rand() Returns a random number. void randomize() Starts a sequence of random numbers. real round(real) Round at nearest of floor or ceil. real sin(real) number sqrt(number) Returns the square root of a number. real tan(real)
Time functions:
int time() Time in milliseconds since January 1, 1970. dict localtime() Current time and date at call into a dictionary, see below.
Keys of the dict returned by localtime:
tm_sec Seconds after the minute [0,61] tm_min Minutes after the hour [0,59] tm_hour Hours after midnight [0,23] tm_mday Day of the month [1,31] tm_mon Months since January [0,11] tm_year Years since 1900 tm_wday Days since Sunday [0,6] tm_yday Days since January 1 [0,365] tm_isdst Daylight Savings Time flag
Exception processing requires an external definition. Syntax:
extern
class exception
string what()
/class
/extern
try
... some statements ...
catch(exception e)
print e.what()
/try
When compiled to JavaScript, the Scriptol langage offers more features, they are described on the site.
Word may be reserved for the target language but are not part of the Scriptol language.
alias
always
and
array
await as async
bool boolean
break
byte
case catch char class
const
continue
define
dict
do
echo
else
enum
error
exception
false
file
finally float
for
forever
from function
global
if
import
in
include
int
integer
is
let
long
mod
nan natural
new nil
not
null
number
or
print
private protected public
react real
return
script scriptol
sol
static
step
super switch
text
this
to true
try
undefined until
var
void
while
yield
zero
© 2001-2016 Denis Sureau.