Extension Modules > Extension Modules

Script BASIC JavaScript Extension Module (Linux)

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The Script BASIC JS extension module for Linux is based on the Cesanta's V7 JavaScript Engine. It claims to be the world's smallest footprint JavaScript 5.1 compatible embeddable engine. There are no other dependencies required.

JavaScript Programmers Guide

V7 JavaScript Documentation

Features:
[*] Dynamically create JavaScript code in Script BASIC and execute the script.,
[*] Call JavaScript functions and access variables from Script BASIC
[*] Create / change JavaScript object properties and methods from Script BASIC
[*] and much more ...
[/list]

Note: The \ character is used by Script BASIC as a string escape character and must be inserted in the JavaScript code to make the \ just text. Loading JavaScript code from a file doesn't have the escape character issue and can be run verbatim.

js.inc

--- Code: Script BASIC ---MODULE JS ' COREDECLARE SUB      js_create                  ALIAS "js_create"                 LIB "js"DECLARE SUB      js_destroy                 ALIAS "js_destroy"                LIB "js"DECLARE SUB      js_get_global              ALIAS "js_get_global"             LIB "js"DECLARE SUB      js_get_this                ALIAS "js_get_this"               LIB "js"DECLARE SUB      js_get_arguments           ALIAS "js_get_arguments"          LIB "js"DECLARE SUB      js_arg                     ALIAS "js_arg"                    LIB "js"DECLARE SUB      js_argc                    ALIAS "js_argc"                   LIB "js"DECLARE SUB      js_own                     ALIAS "js_own"                    LIB "js"DECLARE SUB      js_disown                  ALIAS "js_disown"                 LIB "js"DECLARE SUB      js_set_gc_enabled          ALIAS "js_set_gc_enabled"         LIB "js"DECLARE SUB      js_interrupt               ALIAS "js_interrupt"              LIB "js"DECLARE SUB      js_get_parser_error        ALIAS "js_get_parser_error"       LIB "js" ' PRIMITIVESDECLARE SUB      js_mk_number               ALIAS "js_mk_number"              LIB "js"DECLARE SUB      js_get_double              ALIAS "js_get_double"             LIB "js"DECLARE SUB      js_get_int                 ALIAS "js_get_int"                LIB "js"DECLARE SUB      js_is_number               ALIAS "js_is_number"              LIB "js"DECLARE SUB      js_mk_boolean              ALIAS "js_mk_boolean"             LIB "js"DECLARE SUB      js_get_bool                ALIAS "js_get_bool"               LIB "js"DECLARE SUB      js_is_boolean              ALIAS "js_is_boolean"             LIB "js"DECLARE SUB      js_mk_null                 ALIAS "js_mk_null"                LIB "js"DECLARE SUB      js_is_null                 ALIAS "js_is_null"                LIB "js"DECLARE SUB      js_mk_undefined            ALIAS "js_mk_undefined"           LIB "js"DECLARE SUB      js_is_undefined            ALIAS "js_is_undefined"           LIB "js"DECLARE SUB      js_mk_foreign              ALIAS "js_mk_foreign"             LIB "js"DECLARE SUB      js_get_ptr                 ALIAS "js_get_ptr"                LIB "js"DECLARE SUB      js_is_foreign              ALIAS "js_is_foreign"             LIB "js" ' STRINGSDECLARE SUB      js_mk_string               ALIAS "js_mk_string"              LIB "js"DECLARE SUB      js_is_string               ALIAS "js_is_string"              LIB "js"DECLARE SUB      js_get_string              ALIAS "js_get_string"             LIB "js"DECLARE SUB      js_get_cstring             ALIAS "js_get_cstring"            LIB "js" ' OBJECTSDECLARE SUB      js_mk_object               ALIAS "js_mk_object"              LIB "js"DECLARE SUB      js_is_object               ALIAS "js_is_object"              LIB "js"DECLARE SUB      js_get_proto               ALIAS "js_get_proto"              LIB "js"DECLARE SUB      js_set_proto               ALIAS "js_set_proto"              LIB "js"DECLARE SUB      js_get                     ALIAS "js_get"                    LIB "js"DECLARE SUB      js_def                     ALIAS "js_def"                    LIB "js"DECLARE SUB      js_set                     ALIAS "js_set"                    LIB "js"DECLARE SUB      js_del                     ALIAS "js_del"                    LIB "js"DECLARE SUB      js_init_prop_iter_ctx      ALIAS "js_init_prop_iter_ctx"     LIB "js"DECLARE SUB      js_next_prop               ALIAS "js_next_prop"              LIB "js"DECLARE SUB      js_destruct_prop_iter_ctx  ALIAS "js_destruct_prop_iter_ctx" LIB "js"DECLARE SUB      js_is_instanceof           ALIAS "js_is_instanceof"          LIB "js"DECLARE SUB      js_is_instanceof_v         ALIAS "js_is_instanceof_v"        LIB "js" ' ARRAYSDECLARE SUB      js_mk_array                ALIAS "js_mk_array"               LIB "js"DECLARE SUB      js_is_array                ALIAS "js_is_array"               LIB "js"DECLARE SUB      js_array_length            ALIAS "js_array_length"           LIB "js"DECLARE SUB      js_array_push              ALIAS "js_array_push"             LIB "js"DECLARE SUB      js_array_get               ALIAS "js_array_get"              LIB "js"DECLARE SUB      js_array_set               ALIAS "js_array_set"              LIB "js"DECLARE SUB      js_array_del               ALIAS "js_array_del"              LIB "js" ' EXECUTIONDECLARE SUB      js_exec                    ALIAS "js_exec"                   LIB "js"DECLARE SUB      js_exec_file               ALIAS "js_exec_file"              LIB "js"DECLARE SUB      js_apply                   ALIAS "js_apply"                  LIB "js"DECLARE SUB      js_parse_json              ALIAS "js_parse_json"             LIB "js"DECLARE SUB      js_parse_json_file         ALIAS "js_parse_json_file"        LIB "js" 'REGEXDECLARE SUB      js_mk_regexp               ALIAS "js_mk_regexp"              LIB "js"DECLARE SUB      js_is_regexp               ALIAS "js_is_regexp"              LIB "js" ' UTILITYDECLARE SUB      js_stringify               ALIAS "js_stringify"              LIB "js"DECLARE SUB      js_println                 ALIAS "js_println"                LIB "js" DECLARE SUB      SB_shifts                  ALIAS "SB_shifts"                 LIB "js"DECLARE COMMAND  js_iif                     ALIAS "js_iif"                    LIB "js"  ' JS Global Module VariablesOBJ = 0SYS = 0 ' Stringify ModesDEFAULT = 0JSON    = 1DEBUG   = 2 ' Property Attribute Support CONST V7_PROPERTY_NON_WRITABLE              = 1CONST V7_PROPERTY_NON_ENUMERABLE            = 2CONST V7_PROPERTY_NON_CONFIGURABLE          = 4CONST V7_PROPERTY_GETTER                    = 8CONST V7_PROPERTY_SETTER                    = 16CONST _V7_PROPERTY_HIDDEN                   = 32CONST _V7_PROPERTY_OFF_HEAP                 = 64CONST _V7_PROPERTY_USER_DATA_AND_DESTRUCTOR = 128CONST _V7_DESC_PRESERVE_VALUE               = 256CONST _V7_DESC_MASK                         = &HFFFF CONST PROPERTY_DEFAULT = 0 ' TRUE or FALSE. Whether the property's value can be set.FUNCTION WRITABLE(v)  IF v THEN    WRITABLE = PROPERTY_DEFAULT  ELSE    WRITABLE = V7_PROPERTY_NON_WRITABLE  END IFEND FUNCTION ' TRUE or FALSE. Whether the property shows in some loop constructs.FUNCTION ENUMERABLE(v)  IF v THEN    ENUMERABLE = PROPERTY_DEFAULT  ELSE    ENUMERABLE = V7_PROPERTY_NON_ENUMERABLE  END IFEND FUNCTION ' TRUE or FALSE. Whether the property can be deleted and whether its attributes can be changed.FUNCTION CONFIGURABLE(v)  IF v THEN    CONFIGURABLE = PROPERTY_DEFAULT  ELSE    CONFIGURABLE = V7_PROPERTY_NON_CONFIGURABLE  END IFEND FUNCTION ' TRUE or FALSE. When a property is accessed the value is generated by calling a function implicitly.FUNCTION GETTER(v)  IF v THEN    GETTER = V7_PROPERTY_GETTER  ELSE    GETTER = FALSE  END IFEND FUNCTION ' TRUE or FALSE. When a property is set it will implicitly call a function and pass a' value as argument, and the return value of the function is set to the property.FUNCTION SETTER(v)  IF v THEN    SETTER = V7_PROPERTY_SETTER  ELSE    SETTER = FALSE  END IFEND FUNCTION FUNCTION PRESERVE_VALUE    PRESERVE_VALUE = _V7_DESC_PRESERVE_VALUEEND FUNCTION FUNCTION HIDDEN(v)  IF v THEN    HIDDEN = V7_PROPERTY_HIDDEN  ELSE    HIDDEN = FALSE  END IFEND FUNCTION FUNCTION OFF_HEAP(v)  IF v THEN    OFF_HEAP = _V7_PROPERTY_OFF_HEAP  ELSE    OFF_HEAP = FALSE  END IFEND FUNCTION  ' JS API Function Wrappers ' Create V7 instanceFUNCTION CREATE  OBJ = js_create()  SYS = js_get_global(OBJ)  CREATE = OBJEND FUNCTION ' Destroy V7 instanceSUB DESTROY  js_destroy(OBJ)  UNDEF OBJEND SUB ' Return root level (`global`) object of the given V7 instanceFUNCTION GET_GLOBAL  GET_GLOBAL = js_get_global(OBJ)END FUNCTION ' Return current `this` objectFUNCTION GET_THIS  GET_THIS = js_get_this(OBJ)END FUNCTION ' Return current `arguments` arrayFUNCTION GET_ARGUMENTS  GET_ARGUMENTS = js_get_arguments(OBJ)END FUNCTION ' Return i-th argumentFUNCTION ARG(i)  ARG = js_arg(OBJ, i)END FUNCTION ' Return the length (`count`) of `arguments`FUNCTION ARGC  ARGC = js_argc(OBJ)END FUNCTION ' Tells the GC about a JS value variable/field owned by `C` code.SUB OWN(v)  js_own(OBJ, v)END SUB ' User code should also explicitly disown the variables with v7_disown' once it goes out of scope or the structure containing the v7_val_t field is freed.' Returns 1 if value is found, 0 otherwiseFUNCTION DISOWN(v)  DISOWN = js_disown(OBJ, v)END FUNCTION ' Enable or disable GCSUB SET_GC_ENABLED(enabled)  js_set_gc_enabled(OBJ, enabled)END SUB ' It sets a flag that will cause the interpreter to throw an Interrupted ErrorSUB INTERRUPT  js_interrupt(OBJ)END SUB ' Returns last parser error messageFUNCTION GET_ERROR  GET_ERROR = js_get_parser_error(OBJ)END FUNCTION ' Make numeric primitive valueFUNCTION MK_NUMBER(num)  MK_NUMBER = js_mk_number(OBJ, num)END FUNCTION ' Returns number value stored in `v7_val_t` as `double`FUNCTION GET_DOUBLE(v)  GET_DOUBLE = js_get_double(OBJ, v)END FUNCTION ' Returns number value stored in `v7_val_t` as `int`. If the number' value is not an integer, the fraction part will be discarded.FUNCTION GET_INT(v)  GET_INT = js_get_int(OBJ, v)END FUNCTION ' Returns true if given value is a primitive number valueFUNCTION IS_NUMBER(v)  IS_NUMBER = js_is_number(v)END FUNCTION ' Make boolean primitive value (either `true` or `false`)FUNCTION MK_BOOLEAN(is_true)  MK_BOOLEAN = js_mk_boolean(OBJ, is_true)END FUNCTION ' Returns boolean stored in `v7_val_t`: 0 for `false` or' non-boolean, non-0 for `true`FUNCTION GET_BOOL(v)  GET_BOOL = js_get_bool(OBJ, v)END FUNCTION ' Returns `true` if given value is a primitive boolean valueFUNCTION IS_BOOLEAN(v)  IS_BOOLEAN = js_is_boolean(v)END FUNCTION ' Make `null` primitive valueFUNCTION MK_NULL  MK_NULL = js_mk_null()END FUNCTION ' Returns true if given value is a primitive `null` valueFUNCTION IS_NULL(v)  IS_NULL = js_is_null(v)END FUNCTION ' Make `undefined` primitive valueFUNCTION MK_UNDEFINED  MK_UNDEFINED = js_mk_undefined()END FUNCTION ' Returns true if given value is a primitive `undefined` valueFUNCTION IS_UNDEFINED(v)  IS_UNDEFINED = js_is_undefined(v)END FUNCTION ' Make JavaScript value that holds C/C++ `void *` pointerFUNCTION MK_FOREIGN  MK_FOREIGN = js_mk_foreign(OBJ)END FUNCTION ' Returns `void *` pointer stored in `v7_val_t`' Returns NULL `undef` if the value is not a foreign pointerFUNCTION GET_PTR(v)  GET_PTR = js_get_ptr(OBJ, v)END FUNCTION ' Returns true if given value holds `void *` pointerFUNCTION IS_FOREIGN(v)  IS_FOREIGN = js_is_foreign(v)END FUNCTION ' Creates a string primitive valueFUNCTION MK_STRING(strval)  MK_STRING = js_mk_string(OBJ, strval, LEN(strval), 1)END FUNCTION ' Returns true if given value is a primitive string valueFUNCTION IS_STRING(v)  IS_STRING = js_is_string(v)END FUNCTION ' Returns a pointer to the string stored in `v7_val_t`FUNCTION GET_STRING(v)  GET_STRING = js_get_string(OBJ, v)END FUNCTION ' Returns a pointer to the string stored in `v7_val_t`' Returns NULL `undef` if the value is not a string or' if the string is not compatible with a C stringFUNCTION GET_CSTRING(v)  GET_CSTRING = js_get_cstring(OBJ, v)END FUNCTION ' Make an empty objectFUNCTION MK_OBJECT  MK_OBJECT = js_mk_object(OBJ)END FUNCTION ' Returns true if the given value is an object or functionFUNCTION IS_OBJECT(v)  IS_OBJECT = js_is_object(v)END FUNCTION ' Get object's prototype.FUNCTION GET_PROTO(object)  GET_PROTO = js_get_proto(OBJ, object)END FUNCTION ' Set object's prototype. Return old prototype or undefined on errorFUNCTION SET_PROTO(object, proto)  SET_PROTO = js_set_proto(OBJ, object, proto)END FUNCTION ' Lookup property `name` in object `obj`. If `obj` holds no such property,' an `undefined` value is returnedFUNCTION GETS(object, objname)  GETS = js_get(OBJ, object, objname, LEN(objname))END FUNCTION ' Define object property, similar to JavaScript `Object.defineProperty()`FUNCTION DEF(object, objname, attr, value)  DEF = js_def(OBJ, object, objname, LEN(objname), attr, value)END FUNCTION ' Set object property. Behaves just like JavaScript assignmentFUNCTION SETS(object, objname, value)  SETS = js_set(OBJ, object, objname, LEN(objname), value)END FUNCTION ' Delete own property `name` of the object `obj`' Does not follow the prototype chainFUNCTION DEL(object, objname)  DEL = js_del(OBJ, object, objname, LEN(objname))END FUNCTION ' Returns true if the object is an instance of a given constructor / class nameFUNCTION IS_INSTANCEOF(object, classname)  IS_INSTANCEOF = js_is_instanceof(OBJ, object, classname)END FUNCTION ' Returns true if the object is an instance of a given constructor object classFUNCTION IS_INSTANCEOF_V(object, objclass)  IS_INSTANCEOF_V = js_is_instanceof_v(OBJ, object, objclass)END FUNCTION ' Custom multi-property `GET` functionFUNCTION GET_PROPERTIES(object, proparray)  LOCAL objname, value, attr, propcnt  objname = ""  value = 0  attr = 0  propcnt = 1 ' UNDEF proparray  js_init_prop_iter_ctx(OBJ, object)  WHILE js_next_prop(OBJ, objname, value, attr) <> undef    proparray[propcnt, 0] = js_get_string(OBJ, objname)    proparray[propcnt, 1] = js_get_int(OBJ, value)    proparray[propcnt, 2] = attr    propcnt += 1  WEND  js_destruct_prop_iter_ctx(OBJ)  GET_PROPERTIES = propcnt - 1END FUNCTION ' Make an empty array objectFUNCTION MK_ARRAY  MK_ARRAY = js_mk_array(OBJ)END FUNCTION ' Returns true if given value is an array objectFUNCTION IS_ARRAY(object)  IS_ARRAY = js_is_array(OBJ, object)END FUNCTION ' Returns length on an array. If `object` is not an array, 0 is returnedFUNCTION ARRAY_LENGTH(object)  ARRAY_LENGTH = js_array_length(OBJ, object)END FUNCTION ' Insert `value` in `object` at the end of the arrayFUNCTION ARRAY_PUSH(object, value)  ARRAY_PUSH = js_array_push(OBJ, object, value)END FUNCTION '  Return array member at index `index`. If `index` is out of bounds, undefined is returnedFUNCTION ARRAY_GET(object, index)  ARRAY_GET = js_array_get(OBJ, object, index)END FUNCTION ' Insert value `v` into `arr` at 'index`FUNCTION ARRAY_SET(object, index, value)  ARRAY_SET = js_array_set(OBJ, object, index, value)END FUNCTION ' Delete value in array `arr` at index `index`, if it existsSUB ARRAY_DEL(object, index)   js_array_del(OBJ, object, index)END SUB ' Execute JavaScript `js_code`' The result of evaluation is stored in the `return` variable' The 'ok' argument will contain the function's execution success status flagFUNCTION EXEC(code, ok)  EXEC = js_exec(OBJ, code, ok)END FUNCTION ' Same as `v7_exec()`, but loads source code from `path` fileFUNCTION EXEC_FILE(codepath, ok)  EXEC_FILE = js_exec_file(OBJ, codepath, ok)END FUNCTION ' Parse `json_code`' The result of evaluation is stored in the `return` variable' The 'ok' argument will contain the function's parse success status flagFUNCTION PARSE_JSON(json_code, ok)  PARSE_JSON = js_parse_json(OBJ, json_code, ok)END FUNCTION ' Same as `v7_parse_json()`, but loads `json_code` from `path` fileFUNCTION PARSE_JSON_FILE(json_code_file, ok)  PARSE_JSON_FILE = js_parse_json_file(OBJ, json_code_file, ok)END FUNCTION ' Call function `func` with arguments `args`, using `object` as `this`' `args` should be an array containing arguments or `undefined`FUNCTION APPLY(func, object, args)  APPLY = js_apply(OBJ, func, object, args)END FUNCTION ' Make RegExp object. For example, `regex` is `(.+)`, `flags` is `gi`.FUNCTION MK_REGEXP(regex, flags, rcode)  MK_REGEXP = js_mk_regexp(OBJ, regex, LEN(regex), flags, LEN(flags), rcode)END FUNCTION ' Returns true if given value is a JavaScript RegExp objectFUNCTION IS_REGEXP(object)  IS_REGEXP = js_is_regexp(OBJ, object)END FUNCTION ' Generate string representation of the JavaScript valueFUNCTION STRINGIFY(object, convtype)  STRINGIFY = js_stringify(OBJ, object, convtype)END FUNCTION ' Output a string representation of the value to stdout followed by a newlineSUB PRINTIFY(object)  js_println(OBJ, object)END SUB  END MODULE 

Hello JavaScript

--- Code: Script BASIC ---IMPORT js.inc JS::CREATEPRINT JS::GET_INT(JS::EXEC("1 + 1")),"\n"JS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ time scriba js_hello2.sb
2

real   0m0.026s
user   0m0.016s
sys   0m0.008s
jrs@jrs-laptop:~/sb/examples/js$


Fibonacci

--- Code: Script BASIC ---IMPORT js.inc jscode = """function fibonacci(n) {  if (n <= 2) {    return 1;  } else {    return fibonacci(n - 1) + fibonacci(n - 2);  }} print(fibonacci(24));""" JS::CREATEJS::EXEC(jscode)JS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ scriba js_fibonacci.sb
46368
jrs@jrs-laptop:~/sb/examples/js$


Create object, property and attributes

--- Code: Script BASIC ---IMPORT js.inc JS::CREATEmyobj = JS::MK_OBJECT()JS::DEF(myobj, "test", 0, JS::MK_NUMBER(64))JS::SETS(myobj, "test", JS::MK_NUMBER(32))JS::DEF(myobj, "test", JS::WRITABLE(FALSE) OR JS::PRESERVE_VALUE(),JS::MK_NULL())JS::SETS(myobj, "test", JS::MK_NUMBER(16))PRINT "test = ",JS::GET_INT(JS::GETS(myobj, "test")),"\n"JS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ scriba js_deftest.sb
test = 32
jrs@jrs-laptop:~/sb/examples/js$


Load .js file and get properties

--- Code: Script BASIC ---IMPORT js.inc JS::CREATEJS::EXEC_FILE "properties.js"propcnt = JS::GET_PROPERTIES(JS::GETS(JS::SYS,"test"), proparray)PRINT "Property\tValue\tAttribute\n"FOR i = 1 to propcnt  PRINT proparray[i,0],"\t\t",proparray[i,1],"\t",proparray[i,2],"\n"NEXTJS::DESTROY 
properties.js

--- Code: Javascript ---var test = {}; Object.defineProperty(test, 'a', {  value: 1,  writable: true,  enumerable: true,  configurable: true}); Object.defineProperty(test, 'b', {  value: 2,  writable: false,  enumerable: false,  configurable: false}); 

jrs@jrs-laptop:~/sb/examples/js$ scriba js_propfile.sb
Property   Value   Attribute
b      2   7
a      1   0
jrs@jrs-laptop:~/sb/examples/js$


Call JavaScript function

--- Code: Script BASIC ---IMPORT js.inc jscode = """var sum = function(a, b, c) {  print (c);  return a + b; };""" JS::CREATE()JS::EXEC(jscode)func = JS::GETS(JS::SYS, "sum")args = JS::MK_ARRAY()JS::ARRAY_PUSH(args, JS::MK_NUMBER(123.0))JS::ARRAY_PUSH(args, JS::MK_NUMBER(0.456))JS::ARRAY_PUSH(args, JS::MK_STRING("Script BASIC"))result = JS::APPLY(func, 0, args, rcode)PRINT FORMAT("Result: %g\n", JS::GET_DOUBLE(result))JS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ scriba js_callfunc.sb
Script BASIC
Result: 123.456
jrs@jrs-laptop:~/sb/examples/js$


Describe Properties with JavaScript

--- Code: Script BASIC ---IMPORT js.inc ' Create JavaScript instanceJS::CREATE ' Create JavaScript objectJS::EXEC("var myobj = {};")myobj = JS::GETS(JS::SYS, "myobj") ' Create object propertyJS::DEF(myobj, "test", JS::WRITABLE(TRUE), JS::MK_NUMBER(64)) ' Describe object properties with JavaScriptjscode = """var descriptors = {}; Object.keys(myobj).forEach(function(key) {    descriptors[key] = Object.getOwnPropertyDescriptor(myobj, key);}); var objdesc = JSON.stringify(descriptors);"""JS::EXEC(jscode) ' Return JSON formatted result stringPRINT JS::GET_STRING(JS::GETS(JS::SYS, "objdesc")),"\n" ' Release JavaScript instanceJS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ scriba js_defobj.sb
{"test":{"configurable":true,"enumerable":true,"writable":true,"value":64}}
jrs@jrs-laptop:~/sb/examples/js$


JSON / Stringify

--- Code: Script BASIC ---IMPORT js.inc JS::CREATEmyobj = JS::MK_OBJECT()JS::DEF(myobj, "myprop_1", 0, JS::MK_NUMBER(64))JS::DEF(myobj, "myprop_2", 0, JS::MK_NUMBER(1.23))JS::DEF(myobj, "myprop_3", 0, JS::MK_STRING("JavaScript"))PRINT JS::STRINGIFY(myobj, JS::JSON),"\n"JS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ scriba js_stringify.sb
{"myprop_3":"JavaScript","myprop_2":1.23,"myprop_1":64}
jrs@jrs-laptop:~/sb/examples/js$


JavaScript Regular Expression

--- Code: Script BASIC ---IMPORT js.inc jscode = """var output = ['---------- Original String\\n', names + '\\n']; // Prepare two regular expression patterns and array storage.// Split the string into array elements. // pattern: possible white space then semicolon then possible white spacevar pattern = /\\s*;\\s*/; // Break the string into pieces separated by the pattern above and// store the pieces in an array called nameListvar nameList = names.split(pattern); // new pattern: one or more characters then spaces then characters.// Use parentheses to "memorize" portions of the pattern.// The memorized portions are referred to later.pattern = /(\\w+)\\s+(\\w+)/; // New array for holding names being processed.var bySurnameList = []; // Display the name array and populate the new array// with comma-separated names, last first.//// The replace method removes anything matching the pattern// and replaces it with the memorized string—second memorized portion// followed by comma space followed by first memorized portion.//// The variables $1 and $2 refer to the portions// memorized while matching the pattern. output.push('---------- After Split by Regular Expression'); var i, len;for (i = 0, len = nameList.length; i < len; i++) {  output.push(nameList[i]);  bySurnameList[i] = nameList[i].replace(pattern, '$2, $1');} // Display the new array.output.push('---------- Names Reversed');for (i = 0, len = bySurnameList.length; i < len; i++) {  output.push(bySurnameList[i]);} // Sort by last name, then display the sorted array.bySurnameList.sort();output.push('---------- Sorted');for (i = 0, len = bySurnameList.length; i < len; i++) {  output.push(bySurnameList[i]);} output.push('---------- End'); var retstr = output.join('\\n');""" ' The name string contains multiple spaces and tabs,' and may have multiple spaces between first and last names. JS::CREATEJS::EXEC("var names = 'Harry Trump ;Fred Barney; Helen Rigby ; Bill Abel ; Chris Hand ';")JS::EXEC(jscode)PRINT JS::GET_STRING(JS::GETS(JS::SYS, "retstr"))JS::DESTROY 

jrs@jrs-laptop:~/sb/examples/js$ time scriba js_regexp.sb
---------- Original String

Harry Trump ;Fred Barney; Helen Rigby ; Bill Abel ; Chris Hand

---------- After Split by Regular Expression
Harry Trump
Fred Barney
Helen Rigby
Bill Abel
Chris Hand
---------- Names Reversed
Trump, Harry
Barney, Fred
Rigby, Helen
Abel, Bill
Hand, Chris
---------- Sorted
Abel, Bill
Barney, Fred
Hand, Chris
Rigby, Helen
Trump, Harry
---------- End
real   0m0.030s
user   0m0.028s
sys   0m0.000s
jrs@jrs-laptop:~/sb/examples/js$

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