Water Quick Reference Guide
Aug 23, 2006 Language for Simplified Web Services and XML Programming
 
Concise XML Syntax       source   =>   result
Full closing tag <body> the content </body>
Short closing tag <body> the content </>
No content <body/>
Attributes hold any object or expression <thing age=<plus 2 2/> male=true/>.age => 4
Pass arg via keyword <class boat weight=req/>
  <boat weight=123/>.weight => 123
Pass arg via position <class boat weight=req/> <boat 123/>.weight => 123
Comment <!-- code in here is ignored. -->
Subject of call 2.<plus 3/> <!-- 2 is the _subject of the call to plus --> => 5
Object System: everything is an object
Objects Objects have fields, each of which has a key and a value.
  Values can be any type of object. So can keys.
Root: Water Object <!-- all objects have both a _parent field and
  wob as an ancestor, except wob itself --> wob => wob
Generic object thing <!-- a thing can have any fields --> => thing
Named & vector fields wob.<set foo=<thing x=100 y=555 20 30 40/> />
value of field 'x' wob.foo.x => 100
value of field 2 wob.foo.2 => 40
Instance of class? 10.<is_a number/> => true
Basic Operations: get, set, remove
Dot notation <thing bar=5/>.bar => 5
Get value <thing 6="hi"/>.<get 2.<times 3/>/> => "hi"
<thing 6="hi"/>.<get 5 lookup=false
  if_missing='return' default=0/> => 0
Assign variable(s) <set key1="value1" key2="value2"/> key1 => "value1"
Assign field thing.<set material="wood"/> thing.material => "wood"
Field exists? thing.<has "material"/> => true
thing.<has "junk"/> => false
Remove field thing.<remove "material"/> => "wood"
thing.<has "material"/> => false
boolean: true and false
and true.<and false/> => false
or true.<or false true/> => true
not true.<not/> <not true/> 123.<not/> <!--any arg but false returns false-->
=> false
Same object? 5.<is 5/> => true
<thing/>.<is <thing/>/> => false
Same valued fields <thing foo=5/>.<equal <thing foo=5/> /> => true
false values using boolean.from. Other args result in true. boolean.<from "false"/> boolean.<from "no"/>
  boolean.<from "null"/> boolean.<from null/>
  boolean.<from 0/> boolean.<from -1/>
  <!-- all return false --> => false
number
integer 42.<is_a integer/> => true
-1.<is_a integer/> => true
double: floating point 4.53.<is_a number.double/> => true
-0.11.<is_a number.double/> => true
Arithmetic plus minus times divide remainder
plus 2.<plus 3.3/> => 5.3
_subject defaults to 0 <plus 2 3 4/> <!--plus and times take any number of args--> => 9
( 5 * 6 ) / 3 - 1 5.<times 6/>.<divide 3/>.<minus 1/> => 9.0
Rounding integer.<from 5.3 direction='down'/> => 5
Modulus 10.<remainder 3/> => 1
Comparators 7.<more 5/> 5.<less 7/> 5.<more_or_equal 5/> 5.<less_or_equal 5/>
  <!-- all return true --> => true
string
Create string "a_string" 'a_string' <string>a_string</string> <![CDATA[a_string]]>
=> "a_string"
Concatenate "you".<join 2 "me"/> => "you2me"
Length "Water".<length/> => 5
Get a character "Water".0 => <char "W"/>
Substring "Water".<subvector start=0 end=3/> => "Wat"
Index of value "Water".<key_of <char "t"/> /> => 2
Replace string "Water".<replace "Wa" "bet"/> => "better"
Strings are interned "a".<is "a"/> => true
Loose equality " CM".<equal "cm" same_case=false same_whitespace=false/> => true
Data collection or array: vector
Create vectors <vector 5 "a" "bcd"/> <vector> 5 "a" "bcd" </vector>
synonym for vector <v 5 "a" "bcd"/>
Get field value <vector 5 "a"/>.1 => "a"
Indirect <set x=1/> <vector 5 "a"/>.<get x/> => "a"
Vector length <vector 5 "a"/>.<length/> => 2
Sorting <vector "m" "a" "x" />.<sort/> => <vector "a" "m" "x"/>
Reverse <vector "x" "y" "z" />.<reverse/> => <vector "z" "y" "x"/>
2D vector <set Q=<vector 4 5 <vector 6 7 8/> /> /> Q.2.0 => 6
Get from end <vector 5 10 15 20 25 30/>.<last 1/> => 25
Push value on end <vector "a"/>.<insert "z"/> => <vector "a" "z"/>
Insert at index <vector "a"/>.<insert "z" at_key=0/> => <vector "z" "a"/>
Append vector values <v 6 7/>.<insert _other_unkeyed=<v 8 9/> /> => <vector 6 7 8 9/>
Remove <vector "a" "b" "c"/>.<remove 1/> => "b"
Subvector <vector 6 7 8 9/>.<subvector start=1 end=3/> => <vector 7 8 />
datetime, etc
Create datetime <datetime year=2000 month=12 day=25 hour=5
   minute=50 second=45 millisecond=750/>.minute => 50
Now datetime.<current/>.<is_a datetime/> => true
Create duration <duration months=1 days=9/> => <duration months=1 days=9/>
date plus duration <date 2005 4 1/>.<plus <duration days=32/>/> => <date 2005 5 3/>
Grouping expressions: do
Execute all ... <do 0.<sin/> 0.<cos/> /> => 1.0
& return last result <do> <set x="all done"/> x </do> => "all done"
Code within HTML <h1> <do 2.<power 3/>/> </h1> => <h1 0=8/>
Conditional flow control: if
Condition-action pairs, use do for big action, 'else' means true, return executed action <if> number.double.pi.<more 4/> "high"
   number.double.pi.<less 3/> <do> <echo "bug"/> "low" </do>
   else "just right"
  </if> => "just right"
Returns null if no match <if> 3.<is 2/> "never happens" </if> => null
Iteration: for_each
Iterate over vector fields, return last <vector "a" "b"/>.<for_each> <vector key value/></> => <v 1 "b"/>
Iterate over string fields <thing a=7 b=8/>.<for_each include=string_key combiner=plus>
   value </for_each> => 15
Iterate over 0 thru 3 4.<for_each combiner=plus> value </> <!-- 0.<plus 1 2 3/>--> => 6
Return vector of values <vector 7 8 9/>.<for_each combiner=insert> value.<times 10/> </>
=> <v 70 80 90/>
Return filtered vector <v "k1" "j1" "j2" "k2"/>.<for_each combiner=insert>
   <if> value.<starts_with "k"/> value
   else skip
   </if> </for_each> => <v "k1" "k2"/>
Exclude fields <vector 97 98 99/>.<for_each exclude=<vector 0 2/> combiner=insert>
   value </for_each> => <vector 98/>
Methods, Functions, Macros: method
method & call <method five> 5 </> <five/> => 5
One required arg <method twice x=req> x.<plus x/> </> <twice 3/> => 6
Method on person person.<method hire
Required arg manager=req
Typed arg position=req=string
Default value date=<datetime/>.<current/>
Optional, no default salary=opt=number
End parameters >
Implementation <join "Boss: " manager " hires: " position />
End method </method>
Call the method person.<hire "J.B." "sales"/> => "Boss: J.B. hires: sales"
Execution kinds permit delayed execution <method m x=req=string=ekind.string>
   <if> x.<starts_with "<"/> <execute source=x/> else x </if></>
  <v <m <plus 4 5/>/> <m junk/>/> => <v 9 "junk"/>
Classes: class
Define class <class person first=req last=opt zip=opt/> => person
... with param types <class person first=req=string
   last=req=string zip=opt=integer/> => person
Construct instance <person zip=10483 first="Mike" last="Jones"/>
...without keywords <person "Mike" "Jones" 10483/>
Define subtype <class person.employee/> => person.employee
Define a class with a method and a subtype <class person last=req first=opt><!--put req params 1st-->
   <method hire> "code" </method>
   <class employee employee_id=req> "more defs" </> </class>
=> person
Get subclass person.employee <!-- classes hold subclasses in fields -->
Special methods are : 'make' as constructor, 'to_htm' for display <class person name=req>
   <method make> _subject.<set age=10/> _subject </>
   <method to_htm> <h1><do .name/></h1>.<to_htm/> </> </> => person
Multiple inheritance <<union <class car wheels=4/> <class boat hull="mono"/>/>
   wheels=4 hull="twin"/>
Presentation: XHTML and Hypertext
All XHTML is included in Water html, body, table, form, script, style, div, span, b, i, etc.
  (Tag names can use either upper or lower case.)
Mix html and Water <font size=3.<plus 4/>> <i>Now <do datetime.<current/>/></i></font>
CSS <h1 style=<style color="red"/> >Title</h1>
Web server using HTML form
XHTML input form, input, select, textarea
Web app on integer. Action is method to call with arg from input when submit button clicked <method integer.square in=2>
   <FORM action="/square">
   Enter an integer:<INPUT name="in" value=in.<power 2/> />
   <INPUT type="submit" value="Square It"/> </FORM></method>
Launch server <server integer port=9090/>
Get page from Water <resource "http://localhost:9090/square?"/>.content
Browse the app <open_browser_window "http://localhost:9090/square?"/>
Importing/parsing
string to primitive primitive.<from "123"/> => 123
Returns vector "C,Fry,2".<make_object field_separator=","/> => <v "C" "Fry" "2"/>
Returns person <class person first_name=req last_name=req zip="00000"/>
  "M|Joy|28840".<make_object maker=person field_separator="|"/>
=> <person first_name="M" last_name="Joy" zip="28840"/>
Vector of objects "C,Fry,28838===M,Plusch,02481".
   <make_objects person field_separator="," object_separator="==="/>
=> <v <person "C" "Fry" "28838"/> <person "M" "Plusch" "02481"/>/>
Convert to XHTML "<body bgcolor=red>hello</body>".<html_to_xhtml/>
=> '<body bgcolor="red">
  hello
  </body>'
Output
Object to String <b>Water</>.<to_htm/> => "<b>Water</b>"
Format XML 1.0 <thing weight=123/>.<to_xml/>
=> "<thing>
   <fields>weight=123 </fields></thing>"
Make path if possible number.integer.<to_cxs/> => "number.integer"
Text, no markup <thing size="xl"/>.<to_txt/> => "thing size=xl"
Tools
Print to Java console <echo "X: " <plus 2 3/>/> <!-- all arg values printed--> => 5
Inspect object or path "foo".ii thing.<iip p/> 3.<plus 4/>.ii.<plus 1/> => 8
Make test case <test result=5> 5.<minimum 8/> </test>
Make documentation <doc on=minimum> return the smallest number</doc>
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