Teilz

Teilz (pronounced "tails") is a tiny embeddable scripting language, written in typescript, and created primarily to support the zdani text game. It stands for "terrifically easy instruction language for zdani".

Features:

• basic-like: most instructions start with a keyword like let or for
• sandboxed: user code runs with limits on the number of instruction cycles and recursion depth, in a restricted environment
• strongly typed: every expression is type-checked, without explicit type declarations, because the syntax is kept extremely simple and all types are inferred at parse time
• extensible: custom types and instructions can (and should) be added by the container
• simple: all variable references start with @ to distinguish them from instructions; symbols are only used when their meaning has general consensus across all programming languages (; and { ... } and the method call syntax, for example)
• no "advanced" features like user-defined functions or classes

Builtin types:

• Boolean
• Number
• String
• Array(A) (array of some other type)
• Optional(A) (holds some A or none)

Builtin instructions:

• binary infix operators: * / mod + - == != < > <= >= and or
• unary operators: not
• assignment: :=, let
• conditions, loops, multi-way branches: if, for, match
• list expressions: any, all, count, sum, min, max (with implicit map & filter)
• method calls / message passing: @x.set(3, "tomato")
• format strings: anything in mustaches is parsed as an expression to be stringified: "Double x is {{@x * 2}}"

All of the builtin types may be used as compile-time constants: true, 23, "carrot", [ 1, 2, 3 ]. When you add custom types, you can define syntax so they can be used as constants too.

Example code

Assuming the container adds a print instruction, and defines a local variable named @players of type Array(Player):

for @p in @players where @p.wizard do {
    print "There is a wizard here: {{@p.name}}";
    if @p.username.length mod 2 == 1 then print "Their username is... odd.";
}

Syntax

FIXME

Embedding

FIXME

License

Apache 2 (open-source) license, included in 'LICENSE.txt'.

Credit and blame: Robey Pointer [email protected]