AMI Script Introduction

Overview

AMI has an embedded, versatile language which is a combination of the well-known C/Java style, SQL and String Templating languages. Here is a very quick example of the incredible versatility of the language which does a cross-database join:

 1{
 2  //Inspect the ACCOUNTS table of two pre-defined databases (qadb & proddb).
 3  //Two temporary in-memory tables are created (qatemp and prtemp)
 4  String table = "ACCOUNTS";
 5  CREATE TABLE qatemp AS USE datasource=qadb   EXECUTE SELECT * FROM ${table};
 6  CREATE TABLE prtemp AS USE datasource=proddb EXECUTE SELECT * FROM ${table};
 7
 8  //Gather some statistics, Note that the results of the queries on the in-memory tables are
 9  //stuffed into the local variables
10  int qaCnt = select count(*) from qatemp;
11  int prCnt = select count(*) from prtemp;
12  int bothCnt = select count(*) from qatemp, prtemp where qatemp.id == prtemp.id;
13
14  //Alert the user with some statistics, including the number of users in both qa and prod
15  session.alert("Found ${qaCnt + prCnt} ${table} rows: ${qaCnt} in qa and ${prCnt} in prod. \
16                 There are ${bothCnt} ids existing in both");
17
18  //Create a Temporary ProdOnly table that contains all users in prod but not qa.
19  //This table can be used in the visualization layer
20  Create table ProdOnly as select * from prtemp where !(id in (select id from qatemp));
21}

In this introductory language you can see the interoperability of SQL and a procedural style language. The ${...} syntax is used for easily creating dynamic strings and SQL statements.

Key Features

AMI Script is a versatile language designed for optimized "on the fly" compilation, meaning expressions can be re-compiled and evaluated in an instant. Some key features of the language:

Type Safe - All variables have well defined types, ex: String vs. Integer
Compile Time Binding - Code is compiled before execution to minimize runtime issues
Procedural - Custom methods (with overloading), along with a set of predefined procedures
Object Oriented - Objects in AMI are represented as such in Ami Script
Event Driven - Executes based on events, such as running a datamodel or clicking a button
Implicit Casting - Casting from one type to another can be explicitly or implicitly defined
Embedded SQL - For accessing external sources and tables directly in the language. See below
String Templating - Ability to template code for reuse. See below
Task Swapping - Tasks can be exported runtime for out-of-band execution. (separate thread)

Embedded SQL is an SQL-style language extension to AMI Script with near-full SQL support along with several enhancements geared towards data preparation for the visualization of data. All of these functions act on an in-memory database. It also supports "calling out" to external datasources. Some key features are:

Query Clauses - For filtering, joining, and grouping data on the in-memory database
Data Modification - For adding, updating, and deleting data on the in-memory database
Schema Modification - For adding, editing, and deleting tables/columns on the in-memory database
Use … Execute - For seamlessly running code on external datasources and storing results to the in-memory database
Advanced Data Preparation and Analysis - For complex data calculations, not typically available on a standard SQL database
Lambda Support -The ability to run AMI script code inside SQL. For example, to run a code snippet per row returned in a table
Nested Queries - The in(…) clause supports full nested queries, and also supports multiple column in-clauses
Intelligent Indexing - As joins, in-clauses, etc. are evaluated, indexes will automatically be spun up depending on data size and cardinality

AMI Script Template syntax is an extension of AMI Script with the aim of simplifying dynamic text generation, useful for creating dynamic HTML, dynamic SQL, etc.

Embed Ami Script inside Text - Embed AMI script inside text allows for easy dynamic text generation
Embed Ami Script inside SQL - Embed AMI script inside SQL allows for easy dynamic SQL generation
Injection Protection - Properly escaping control characters, quotes, etc.
Conditional Templating - Ability to do conditional & loop based template construction

AMI Script - A java syntax with embedded SQL and String Templates

Syntax

Same support as java for loops, if/else statements, white space, comments and expressions:

1double n=0;
2for(int i=0;i<10;i++){
3    if(i < 5)
4      n++;  //increment a number
5}
6/* sample expression, same as java*/
7int b=4 > 5 ? 1 * 2 : 5 / 2;

Data Structures

General purpose List, Map, Set & Table data structures are provided. The constructors can be used to prepopulate data:

1List mylist=new List(1,2,3,4);
2Map mymap=new Map(“fname”,”Eric”,”lname”,”Johnson”);
3Set set=new Set("a", "b", "c");
4Table =new Table("People", "user String, age int");

Type Safety & Coercion

Type names are case insensitive, ex double and DOUBLE are the same. For compatibility, int and integer mean the same thing as well as char and character.

1int n=5;
2Int m=n*n;
3INTEGER o=m*m;

All types support null value. Dereferencing null, results in null. Expressions with null result in null

1List l=null;
2Integer s=l.size();  //s is null, does not raise null pointer
3Double n=5,m=null;
4Double p=n*m;//p is null because anything times null is null

Flexible type coercion. When coercion is not possible the value is coerced to null.

1Int value="123"; //value will be 123
2Double value2=new List(); //list can’t be cast to double so value2 will be null
3String value3=new List(1,2,3);  //value3 is the string [1, 2, 3]

All types extend Object and casting is not necessary for assignment.

1Object o=new List(1,2,3);
2List l=o; //this works because the value of o is a List.
3Map m=0; //m will be null because a List can not be cast to a map

All types can be thrown / caught and all blocks can have catch clauses (try key word is not necessary)

1{
2   throw "what!";
3}catch(String s){
4}

String Templates

If strings contain a ${...} the content of the curly brackets is interpreted

1String name="rob";
2String message1="hello ${name}"; // hello rob
3String message2="A baker’s dozen is {12+1}"; // A baker’s dozen is 13

You can use triple quotes for literals:

1String m="""hello ${world}"""; // hello ${world}

SQL

There are several reserved words that indicate an sql statement, including CREATE, SELECT, INSERT, DELETE, etc.

1CREATE TABLE T(username String, id int);
2INSERT INTO t values ("rob",111),("dave",222");  //table t has 2 rows
3CREATE TABLE t2 as select * from t where id<200; //table t2 has 1 row

Variables and templates can be used inside sql:

1String name="eric";
2Int id=333;
3INSERT INTO T VALUES(name,id); //inserts eric,333
4String row="values (\"mike\",444)";
5INSERT INTO T ${row};//expands to INSERT INTO T values("mike",444);

Table coercion works for Table cells to objects, Columns to Lists and Rows to maps.

1String s=select username from t where id==111; //s=rob
2List names=select username from t; //names= [rob, dave]
3Map user=select * from t where id=222; //user={username=dave, id=222}

To query external data sources run the USE ds= … EXECUTE command.

1CREATE TABLE t3 as USE ds="mydatabase" EXECUTE SELECT * FROM ORDERS;
2//RAN SELECT * FROM ORDERS on the mydatabase datasource and created a local table called t3

To upload data to external data sources run the USE ds= … INSERT command.

1USE ds="targetdb" INSERT INTO TargetAccounts FROM useds="sourcedb" SELECT * from SourceAccounts;//query all data fromsourcedb’s SourceAccounts table and insert into targetdb’s TargetAccounts table

Custom Methods

Methods are static and must return a type. If a return is clause is not reached, the function returns null.

 1String combine(String s,String t){
 2
 3   if(s!=null && t!=null)
 4
 5     return s+" "+t;
 6
 7}
 8
 9String s=combine("apple","orange");//s is now apple orange
10String t=combine("apple",null);//t is null

AMI Script

Variable Naming

Case-sensitive combination of a-z, A-Z, _, 0-9. The first character must not be a number. Alternatively, variables can be wrapped in back ticks (`), in which case all characters are supported, allowing for accessibility with external language references. Note: `test` is equivalent to test. Variables are declared with the following syntax (the value will default to null if an expression is not supplied):

type variable_name [ = expression][, variable_name [ = expression] ... ];

Literals (Constants)

digits	Int constant
0xdigits	Hex Int constant
0digits	Octal Int constant
digitsL	Long constant
0xdigitsL	Hex long constant
0digitsL	Octal long constant
digits.digits	Float constant. Note, scientific (aka 'E') notation is supported
digits.digitsD	Double constant. Note, scientific (aka 'E') notation is supported
"chars"	String constant. Use backslash (\) to escape quotes, backslash (\\) and other control chars, ex: \n. A string can be defined over multiple lines using a trailing backslash on all but the last line, note that preceding white space is trimmed out for subsequent lines. Please see String Templating section for details on ${…} syntax
\n\r\t<space>	White space (token delimiter)

Reserved Type

All reserved types' values are immutable. Null is a valid value

Long	64 bit signed whole number
Double	64 bit signed float
String	Variable length string of UTF 8 characters
Integer	32 bit signed whole number
Float	32 bit signed float
Byte	8 bit signed whole number
Boolean	boolean (true or false)
Number	Base class for Long,Double,Integer,Float,Byte
UTC	Timestamp with millisecond precision (since unix epoch)

Examples

Integer i = 32;
Double d = 4.3, f = 132.d; //declaring multiple variables
Integer j = 0xaabcc;
String test = "hello world";
String Test = "Hello \
               world";     //Multi line 
Integer lng = 100000000000L;
Boolean flag = true;
Byte some_thing = null;

Casting

Variables are strongly typed, but casting can be explicit or implicit. If a cast fails, the result evaluates to null. Also, equality operations (==, <=, >=, >, <, !=) will also auto cast when possible as well.

Examples

String test1 = 123;    //implicit cast from integer to string 
String test2 = "0x123";//implicit cast from hexidecimal integer to string 
Double val = "123.32"; //implicit case for string to double 
Boolean b = "true";    //implicit cast from string to boolean
String val = (Integer) 123.d; //explicit cast from double to integer, then implicit cast to String
Boolean c = "test";    //Evaluates to null because the implicit cast from string to boolean is invalid
Byte d;                //Evaluates to null by default

Variable Scoping

Scopes are defined using statement blocks, which are denoted by curly brackets: {…}. Within a statement block, variables are only visible after they are declared. When statement blocks are nested inside other statement blocks, all variables declared in the outer block are visible within the inner block as long as the variable is declared before the inner block. A variable cannot be re-declared when another variable with the same name is visible.

Examples

{
  Byte a;
  //a is visible;
  Byte b;
  //a & b are visible; 
  {
    Byte c;
    //a, b & c are visible;
    Byte d;
    //a, b, c & d are visible;
    {
      Byte e;
      //a, b, c, d & e are visible;
    }
    //a, b, c & d are visible;   
  }
  //a & b are visible;
  Byte a; //Compiler error: a already exists and can not be redefined
}

Standard Operators (in order of significance)

math_expressions

(evaluates to num_var type)

num_expr	*	num_expr	multiplication
num_expr	/	num_expr	division
num_expr	%	num_expr	modulus (remainder)
num_expr	+	num_expr	addition for numbers
num_expr	-	num_expr	subtraction

binary_expressions

(evaluates to num_int_expr type)

int_expr	~	int_expr	bitwise NOT
int_expr	<<	int_expr	signed bit shift left
int_expr	>>	int_expr	signed bit shift right
int_expr	>>>	int_expr	unsigned bit shift right
int_expr	&	int_expr	bitwise AND
int_expr	^	int_expr	bitwise XOR
int_expr	!	int_expr	bitwise OR

boolean_expressions

(evaluates to boolean)

	!	bool_expr	boolean (logical) NOT
expr	<	expr	less than (strings are case sensitive)
expr	>	expr	greater than (strings are case sensitive)
expr	<=	expr	less than or equal to (strings are case sensitive)
expr	>=	expr	greater than or equal to (strings are case sensitive)
expr	==	expr	equal to (strings are case sensitive)
expr	!=	expr	is not equal to (strings are case sensitive)
expr	=~	regex	matches regular expression (see Java Pattern for details)
expr	!~	regex	does not match regular expression (see Java Pattern for details)
expr	~~	simple_pattern	simplified text matching. See Simplified Text Matching section.
expr	instance of	type	does expr evaluate to supplied type (eg: would casting succeed)
expr	&&	expr	logical and. Short circuits if left expr returns false. Short circuits if right expr is const and false
expr		expr	logical or. Short circuits if left expr returns true. Short circuits if right expr is const and true

string_expressions

(evaluates to boolean)

string_expr+ expr	String concatenation. Null values equate to empty string ("")

special_expressions

(expression)	Force Order of operations
array_of_type[num_expr]	Array index referencing
(type)statement	Explicit cast to type. Note that a failed cast returns null. Also, casting is automatic, so it's not necessary
bool_expr ? tr_expr : fl_expr	If bool_expr returns true, then evaluates to tr_expr, otherwise evaluates to fl_expr.

Examples

Long n = (10 + 5) * 2;  //n is 30 
n += 5;                 //n is 35 
n = n/2;                //n is 17 
Boolean b = n>10;       //b is true (n is still 17)
b =! b;                 //b is false 
b = (b || true) && true;//b is true         
String test = "hello" + "world"; //test is helloworld

Assignment & Declaration

special (evaluates to type)

new type(param[, param ...])	Object Creation
type var_name	Variable declaration (Value is defaulted to null)
type var_name = expression	Variable declaration and assignment
Variable declaration and assignment	Variable declaration and assignment

assignment (evaluates to num_var type)

num_var	++		combined post-increment assignment
	++	num_var	combined pre-increment assignment
num_var	--		combined post-decrement assignment
	--	num_var	combined pre-decrement assignment
num_var	*=	num_expr	combined multiplication assignment
num_var	/=	num_expr	combined division assignment
num_var	%=	num_expr	combined modulus assignment (remainder)
num_var	+=	num_expr	combined addition assignment
num_var	-=	num_expr	combined subtraction assignment

Flow Control

Complex AMI scripts can be achieved by combining multiple statements into statement blocks. A statement block is wrapped in curly brackets {...} and each statement is separated with a semi-colon;. Then, the execution of statement blocks can be determined using a variety of flow control statements including if, if/else, for, while, and for-each-loops. Note that for and while loops can use the continue and break directives as well. Examples

{
  Integer count = 10;
  Integer value = 1;
  for(Integer i = 0; i < count; i++){
    value *= 2;
  }
  if(value < 2000) {
    session.alert(value); //alert shows 1024
  } else   
    session.alert("High value"); // this is never hit. Also note: single statements don't need to be in {...} statement blocks
  while(true){
    value -= 10;
    if(value < 1000)
      break;
  }
  //value is now 994 
}

statement block

{ statement [;statement ...] [;]}

** Evaluates to return value if a return_statment exists, otherwise it evaluates to the last statement's evaluation. If no statements, evaluates to Void

for loop

for(initialization;termination_expression;increment) statement

initialization: statement that is called first, used to declare variables with local scope

termination_expression: statement that must evaluate to boolean, false terminates

increment: statement called after each completion of the loop's statements

statement: called once per loop. Note:

continue_statement will exit the statement and proceed to increment statement

break_statement will exit the for loop entirely

**Evaluates to Void

for each loop

for(type_expr  varname:iterable_or_array) statement

iterable_or_array - values to iterate over in order

statement: called once per loop. Note:

continue_statement will exit the statement and proceed to increment statement

break_statement will exit the for loop entirely

**Evaluates to Void

while loop

while(bool_expression) statement

same as for(;bool_expression;) statement

**Evaluates to Void

if statement

if(bool_expression) statement

if bool_expression evaluates to true then execute statement

**Evaluates to Void

if else statement

if(bool_expression) statement else statement2

if bool_expression evaluates to true then execute statement otherwise executestatement2

**Evaluates to Void

return statement

return statement

** Evaluates to statement's value. Will cause call stack to be popped out to caller function.

break statement

break

** See for_loop, for_each_loop and while_loop

continue statement

continue

** See for_loop, for_each_loop and while_loop

function call

function(param[, param ...])

**Evaluates to return_type value

member method call

target_object.function(param[, param ...])

**Evaluates to return_type value

Objects

There is a predefined set of object types (classes). These are used to facilitate the interaction between AMI Script and various backend components, user inputs, dashboards, etc. Additionally, data structures are represented as objects and can be instantiated using the new operator. Objects can only be accessed via methods (not member variables).

The Session Object

session - each user that is logged in has a session object (which is of type Session). This is the "starting point" for access to the user's information, along with various dashboard components.

Common Data Structures

List: A zero-indexed Array List implementation

Set: A set of unique values

Map: A Linked Hash Map implementation

Table: A 2-dimensional table with the same characteristics as a SQL style table. Tables have a title. Columns are named and strongly typed.

Tableset: A map of tables. Can be loosely thought of as a mini database.

Examnples

session.alert("this is a test");
session.log("something worth logging);
List l = new List("apple", "orange", "berry", "banana");
l.splice(1, 2, "strawberry");
String s = l;                                //s is now apple, strawberry, banana
Map m = new Map(1, "one", 2, "two", 3, "three");  //map contains three key/value pairs, ex: 2 = "two"

Commenting

Commenting is identical to the commenting syntax in Java & C++. There are two types of comments: single-line and multi-line.

comments (single-line)

//comments<linefeed>

comments (multi-line)

/*comments*/

Examples

/*multi-line
comment using the
slash stars*/
//single-line comment

AMI Script Constants

AMI Script can reference constants just like other variables. Note the constant's values can not be changed using AMI Script. The standard naming convention for global variables is 2 under bars (__) followed by an all uppercase name. Constants can be defined in three ways:

At the server level (via a config file loaded at startup, typically local.properties)

Typically the syntax is: amiscript.variable.varname=value

(note that if value is a string, is must be surrounded in double quotes, see LITERALS for details)

For example, this could reside in your local.properties:

#My custom variables

amiscript.variable.__COMPANY_NAME="Acme Technologies"

amiscript.variable.__COPYRIGHT=2017

At the user level (using the authentication plugin, or the access.txt file)

Typically the syntax is: amiscript.variable.varname=value

(note that if value is a string, is must be surrounded in double quotes, see LITERALS for details)

For example, this could reside in your access.txt file for user demo (with password demo123):

demo|demo123|amiscript.variable.__GROUP="infosec"|amiscript.variable.__SECURITY_LEVEL=12

There are also pre-determined variables defined by the AMI Web system:
- __USERNAME: (String) the username of the logged in user
- __SESSIONID: (String) a unique id for the web session
- __TIMEZONE: (String) the timezone of the user's session
- __ADDRESS: (String) the ip address of the user's browser
- __LOADTIME: (Long) the time in milliseconds that the user started the session
- session: (Session) the session object representing the user's session

Hint: Through the front end in editor mode you can view all declared constants via: Menu Bar -> Dashboard -> Variable Table

SimplifiedText Matching

Overview

The simplified text matching finds text entries using a simple pattern. When included in AMI script, it takes the form: var ~~ "my pattern"

Rule 1, the general case: the pattern supplied will match any text that contains the pattern, case insensitive. For example, assuming word is a variable let's consider the expression: word ~~ "AB". This will return true if word is cab or ABC or tabs but will return false if word is apple.

Rule 2, special symbols: If you need to look for symbols besides letters, numbers or white space, prefix with a back slash. For example, to look for the word P&L, the expression is word ~~ "P\&L". Note this includes the following list of symbols: *^$.[]()~|&!?:

Rule 3, Additional syntax: There are many special symbols that can be used for more advanced searches, for example the star (*) means anything, so "f*g" will match any thing that has an f followed by g, such as 3FORGE. See the following sections for more advanced syntax.

Syntax The following syntaxes are used to do "basic" matching against expressions with some text.

1. Simple Matching Expression

Matches any text that contains the supplied pattern regardless of case. The following characters are reserved and may be embedded in the expression:

* - Anything: Can be expanded to include any text.
^ - Starts With: Symbolizes the "start" of the text. In other words, if an expression starts with ^, then the text must start with the following expression. Please note that carets (^) not at the start of the expression will be treated as literals. (When used in conjunction with the tilde (~), the hat should follow the tilde.)
$ - Ends With: Symbolizes the "end" of the text. In other words, if an expression ends with a dollar sign($) then the text must end with the preceding expression. Please note that dollar signs not at the end of the expression will be treated as literals.
. - Any single char.: Will match to one character of any value.
[charlist] Any of Chars.: Match any one of the characters enclosed within the brackets.
~: Case Sensitive. If the first character, indicates that matching characters should be case sensitive.
Escaped chars: When referencing the following characters literally, they must be escaped with a back slash (\): *^$.[]()~|&!?:
Literals: These are simply letter-for-letter matches to the expression

2. 'Exact Expression'

Matches the exact expression supplied in quotes (other than an escaped quote using \' ). This would be similar to using an equals ( == )

3. /regex/<options>/

This will use the java.util.regex package to match against regular expressions (see the java.util.regex.Pattern for details on building regular expressions). The <options> allow you to control behavior of how the regular expression operates. Simply supply the options you would like to apply in a continuous string between the 2nd and last forward slash (/). The following options are supported:

q - Canonical Equivalence: When this flag is specified, two characters will be considered to match if and only if their full canonical decompositions match. The expression "a\u030A", for example, will match the string "?" when this flag is specified. By default, matching does not take canonical equivalence into account.
f - Full Line: When this flag is specified, the text must fully match the regular expression. If this option is not specified, any portion of the text matching the expression will be considered a match.
i - Case Insensitive: By default, case-insensitive matching assumes that only characters in the US-ASCII charset are being matched. Unicode-aware case-insensitive matching can be enabled by specifying the u (Unicode case) flag in conjunction with this flag.
c - Comments: White space is ignored, and embedded comments starting with # are ignored until the end of a line.
l - Literal: White space is ignored, and embedded comments starting with # are ignored until the end of a line.
d - Disable Dot All: If the disable dot all flag is set then the dot expression (.) will match any character except a line terminator. By default, the dot expression only matches line terminators.
m - Multiline: In multiline mode the expressions ^ and $ match just after or just before, respectively, a line terminator or the end of the input sequence. By default, these expressions only match at the beginning and the end of the entire input sequence.
u - unicode Case: When this flag is specified, case-insensitive matching, enabled by the i (case insensitive) flag, is done in a manner consistent with the Unicode Standard. By default, case-insensitive matching assumes that only characters in the US-ASCII charset are being matched.
x - Unix Lines: In this mode, only the '\n' line terminator is recognized in the behavior of ., ^, and $.
v - Not Matching: Reverses the matching result. Expressions that normally would match will not match and expressions that would not normally match will match.
n - No Error: If the regular expression is invalid do not throw an exception, instead just always return false, unless the v flag is also set, in which case always return true.

4. <null>

Null String - providing null will result in a matcher which matches nothing.

5. <Empty String>

Providing an empty (zero length) string to the Matcher method will result in a matcher which matches only the empty string.

Conjugated Syntaxes

The following syntaxes allow for more complicated pattern matching. Nested syntaxes may also be conjugated syntaxes. For nested syntaxes which are basic syntaxes open parenthesis [ ( ] and close parenthesis [ ) ] must be escaped with a backslash [ \ ].

6. (Expression): The parenthesis can be used to force order of operations, important when mixing or [ | ] and and [ & ] clauses.

7. Expression1|Expression2: If either of the nested expressions match this expression will return true.

8. Expression1&Expression2: If both of the nested expressions match this expression will return true.

9. !Expression: Inverts the result of the expression.

10. (Expression) ? (ExpressionTrue) : (ExpressionFalse): If the Expression matches, return result of ExpressionTrue Otherwise return result of ExpressionFalse.

Sample Expressions

Expression	Examples Match	Examples Mismatch	Comments
FORG	3Forge	Frg	Partial text, Case insensitive match
~FORG	FORGE	forge	Partial text, Case sensitive match
^FORG$	FORG	FORGE	Exact text, Case insensitive match
~^Forge$	Forge	forge	Exact text, Case sensitive match
!FORG	3FOR	3FORGE	Escape partial text, case insensitive
!^FORG$	FORGE	FORG	Escape exact text, case insensitive
[RB]ob	Bobby	lob	Using char list
[A-Z]ob	mob	7ob	Char list range
3F*ge	3Forge llc	Forge llc	Wild chars
3f.ge	3Frge	3Forge llc	Match single char
Acme llc\.	Acme llc.	Acme llcc	Escaping special chars
	robert	ted	Or clause partial match
	rob	robert	Or clause, exact match
bob&rob	robob	bobob	And clause partial
'Exact'	Exact	exact	Exact case sensitive text match
		a	Empty string, only matches empty string
a?bb:s	Abba test	acca tent	If contains 'a', must contain 'bb' If doesn't contain 'a', must contain 's'
	af	ab	Must contain a or b. Also must contain e or f
	def	DEF	Must be exactly 'abc' or 'def'
/reg/	regular	Regular	By default, regex must be case sensitive
/reg/i/	Regular	whatever	I option makes case insensitive
	3F reg	3Forge Regular	Mixing regex and non regex

Sample Usage The following snippet of code will print out all of the strings in the textList list that contain the phrase "my expression". See the Syntax section below for the various types of expressions that could be applied the someExpression variable.

 List<String> textList = someTextList;
 String someExpression = "my expression";
 TextMatcher matcher SH.m(someExpression);
 for(String text:textList){
   if(matcher.matches(text))
   System.out.println(text);
 }

AMI String Templating

Goals

String templating is used to ease the dynamic creation of strings. Some key places that benefit from string templating:

HTML generation
SQL generation
Content-rich messages for the end user
Debugging / Logging

Basic Usage

As usual, strings are denoted using double quotes at the beginning and end, ex: "...". Within a string, ${...} is recognized as a special operator. The text between the curly braces is interpreted as code to be executed. For example, the code can be a simple variable name, or a complex set of expressions.

"text${code}text${code}..."

If you wish to include a literal dollar sign followed by a curly bracket, the dollar sign must be escaped with a backslash.

"test\${stilltext}text" //Evaluates to: test${stilltext}text

To prevent against SQL (and other forms) of injections, ${...} wrapped with quotes ('), double quotes (") or back ticks (`) will cause the evaluated text to be escaped with a backslash (\) accordingly:

"text '${code}'" - results of code will have ' escaped to \'

"text \"${code}\"" - results of code will have " escaped to \"

"text `${code}`" - results of code will have ` escaped to \`

For example:

"text `${code}`" - results of code will have ` escaped to \`

String bar = "NAME LIKE '${foo}'"; //result is: NAME LIKE 'Eric\'s'

Finally, null will evaluate to an empty string ("").

Examples

Integer age = 20;
String name = "Sue";
String message2 = "${name} is ${age} year(s) old";     // Simple Case: Sue is 20 year(s) old
String t = "Four times four is ${4 * 4}";              // Complex Expression: Four times four is 16
String t2 = "40/9 is ${formatNumber(40/9d, "#.###")}"; // Calling functions: 40/9 is 4.444
String t2 = "don't replace \${name}";                  // Avoid Template: don't replace ${name}

String d = "ain't";                 
String m1 = "escaping '${d}' easy";                    // Evaluates to: escaping 'ain\'t' easy

Templated Flow Control

The ${...} syntax can also be used to dictate if/how text should be included. This includes all flow control statements, including if-statements, for-loops, for-each-loops, and while-loops. All flow control statements are closed by the ${} token (empty curly brackets).

Flow Control Statement

"[text]\
  ${flow_control(...)}\ 
    [text inside flow control]\
  ${}\
[text]"

** Definition is a multiline string for clarity

Single Line Flow Control Statement

"[text]${flow_control(...)}[text inside flow control]${}[text]"

Ex:

"Count the apples: ${for(int i = 1; i <= 5; i++)} ${i} apple ${} There are 5 apples."

"Count the apples: ${int i = 1; while(i++ < 6)} ${i} apple ${} There are 5 apples."

"Count the apples: ${if(5 > 3)} apple apple apple apple apple ${} There are 5 apples."

For if/else use the reserved ${else} token:

If/else Statements

"[text]\
  ${if(...)}\
    [text inside if statement]\
  ${else}\
    [text inside else statement]\
  ${}\
[text]"

** Definition is a multiline string for clarity

Single Line If/else Statements

"[text]${if(...)}[text inside if statement]${else}[text inside else statement]${}[text]"

Ex:

"Count the apples: ${if(5 < 3)} apple ${else} orange ${} There is one orange."

Flow control statements can be nested:

Nested Flow Control Statements

"[text]\
  ${flow_control_outer(...)}\
    [text inside outer flow_control]\
    ${flow_control_inner(...)}\
      [text inside inner flow_control]\
    ${}\
    [text inside outer flow_control]\
  ${}\
[text]"

** Definition is a multiline string for clarity

Single Line Nested Flow Control Statements

"[text]${flow_control_outer(...)}[text inside outer flow_control]${flow_control_inner(...)}[text inside inner flow_control]${}[text inside outer flow_control]${}[text]"

Ex:

"Courses:\n \
    ${for(int i = 120; i < 122; i++)} \
      Course: Math${i}\n \
      ${for(int j = 1000; j < 1009; j++) } \
        Students${j}\n \
      ${} \
      Professor For Math${i}:Stern\n \
    ${}\
  ====End===="

Examples

List letters = new List("A", "B", "C");
  String s = "Easy as ${for(int i = 1; i <= 3; i++)} the number ${i} ${}";//Easy as 1 2 3
  String s2 = "${for(String i:letters)} ${i}${},
Easy as ${for(int i = 1; i <= 3; i++)} ${i} ${}";
  //s2 evaluates to: A B C, Easy as 1 2 3 

{
  Map messages = new Map();
  for(int num = 1; num <= 3; num++)
     messages.put(num,"=is ${if(num == 2)}exactly${else}not${} two");
  session.alert(messages); // Evaluates to: {1=is not two,2=is exactly two,3=is not two} 
}

AMI Syntax for Embedding External Languages

Goals

Allow users familiar with other languages to embed familiar code into existing data models.

Enable users to take advantage of existing libraries found in other languages

Syntax

extern language {{
       ...
       embedded_code_in_other_langauge
       ...
}};

Rules on Prefixing and terminating the custom code segment:

The prefix must be at least 2 consecutive opening curly brackets ({).
The termination must have the same number of closing curly brackets (}) as the prefix has.
You can not include the suffix inside the embedded code. So for example, let's say you have a }} inside the embedded code, then you should wrap the embedded code in three curly brackets, ex: {{{custom_code_witha_double_curlys}}}
The embedded code is evaluated literally, ex: all escapes, etc. are sent directly to the sub-language engine

Currently, python is supported out of the box.

Example

{
  int n=5;

  extern python {{
    for i in xrange(2,5):
      n=n*i;
  }};

  session.log(n);// will log 120
}

AMI Reserved WORDS (alphabetical)

ADD ALTER ANALYZE AND AS ASC BEFORE BINARY BOOLEAN BREAK BY CALL CASE CATCH CREATE CONCURRENT CONTINUE DEFAULT DELETE DESC DESCRIBE DISABLE DO DOUBLE DROP ELSE ENABLE EXECUTE EXTERN FLOAT FOR FROM GROUP HAVING IF IN INDEX INSERT INT INTEGER INTO JOIN LEFT LIMIT LONG MODIFY NEAREST NEW OFTYPE ON ONLY OR ORDER PARTITION PREPARE PRIORITY PROCEDURE PUBLIC RENAME RETURN RIGHT SELECT SET SHOW STEP STRING SWITCH SYNC TABLE TABLES TIMER TRIGGER TO TRUNCATE UNION UNPACK UPDATE USE UTC UTCN VALUES WHERE WHILE WINDOW

Reserved words are case insensitive

AMI Script

AMI Script Introduction

Overview

Key Features

AMI Script - A java syntax with embedded SQL and String Templates

Syntax

Data Structures

Type Safety & Coercion

String Templates

SQL

Custom Methods

AMI Script

Variable Naming

Literals (Constants)

Reserved Type

Casting

Variable Scoping

Standard Operators (in order of significance)

math_expressions

binary_expressions

boolean_expressions

string_expressions

special_expressions

Assignment & Declaration

special (evaluates to type)

assignment (evaluates to num_var type)

Flow Control

statement block

for loop

for each loop

while loop

if statement

if else statement

return statement

break statement

continue statement

function call

member method call

Objects

The Session Object

Common Data Structures

Commenting

comments (single-line)

comments (multi-line)

AMI Script Constants

SimplifiedText Matching

AMI String Templating

Templated Flow Control

AMI Syntax for Embedding External Languages

AMI Reserved WORDS (alphabetical)

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