YAML Script

YAML Script is a YAML based scripting language.

Build

To build:

cargo {build | release}

To run tests:

cargo test [-- --nocapture]

Run

To run:

./target/<debug|release>/ys <file>

Example:

./target/debug/ys examples/hello.ys

Syntax

script:

<steps>

steps:

- <step>
...

step:

<var> | <echo> | <if> | <while> | <each> | <break> | <exec> | <def> | <call> | <exit>

(<def> and <call> are not yet implemented.)

var:

<name>: <boolean> | <integer> | <float> | <string> | <list> | <map> | <expression>

(Variables are global. <list> and <map> are not yet implemented.)

echo:

- echo: <expression>

if:

- if: <condition>
  [then: <steps>]
  [else: <steps>]

while:

- while: <condition>
  [do: <steps>]

each:

- each: <name>
  [in: <expression>]
  [do: <steps>]

break:

- break: <condition>
  [message: <string>]

exec:

- exec: <expression>
  [as: <name>]

def:

- def: <name>
  do: <steps>

call:

- call: <name>
  [with:
      <name>: <expression>
      ...]

exit:

- exit: <expression => number>

condition:

<expression> where true = true | non-zero | non-empty

expression:

${<name>} | ${<math-expression>} | ${<boolean-expression>}

(Expressions are handled by https://crates.io/crates/eval.)