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Functions

Functions follow the common code pattern of the reserved name, the function name, parameters, and a code block.

function <name> (parameters) { }

function main() {
	/* 
    This is a special type of function. 
    The main() function is the entry point to code execution
  */
}

The main function is the execution entry point. Other functions and definitions outside the main, but in the file are visible at a Global scope level.

The parameter of a function is the same as that of a TypeScript function. The parameters can be named and have default values.

function hello ({message="Hello World"}) {
  printf("Main meessage ->, %s", message) 
}

function main () {
  hello()
  hello({
    message: "Goodbye",
    unused: "field"
  })
}

In this function, you call hello twice. The first time, there is no argument, so the system uses the default argument. The second time, there is a passed object that has a message field. In this case, the "Goodbye" value is presented.

Functions have proper scoping.

function called() {
	let x = "local"
  printf("%s", x)
  // printf("%s", y)
}

function main () {
	let x = "global"
  let y = "global"
  printf("%s", x)
  called()
}

In the above example, the function called will print the local variable. However, if you tried to refer to the y variable in the called function, the compiler will give a variable undefined error.

case(condition_1, value_1, [condition_2, value_2, …​], default_value)​

evaluate a list of conditions and returns the first value whose condition is evaluated to true. If all conditions are false, the default value is returned

let i = 10  
case(i>10, "bigger than ten", i>=0, "positive", "negative") // return "positive"  
let i = -10  
case(i>10, "bigger than ten", i>=0, "positive", "negative") // return "negative"

template(text, variableMap)​

Generates text output based on input variables. The template format is the same as Golang’s template. The variableMap is a map type holding variables or a json object.

let t = `Value of a: {{.fields.a}}
         List: {{.list}}`  
let opt = `{"fields":{"a":"foo"}, "list": [1234, 5678]}`  
let s = template(t, opt)  
//   Value of a: foo  
//   List: [1234 5678]