feat: add Midas railroad diagrams

syntax/annotations.typ

@@ -9,11 +9,11 @@
 ```
 
 #let constraint = ```
-{[`constraint` "(" <"_", 'value'> <">", "<", ">=", "<=", "==", "!="> <"_", 'value'> ")"]}
+{[`constraint` <"_", 'value'> <">", "<", ">=", "<=", "==", "!="> <"_", 'value'>]}
 ```
 
 #let type-with-constraints = ```
-{[`type-with-constraints` 'identifier' <!, ["+" 'constraint'] * !>]}
+{[`type-with-constraints` 'identifier' <!, ["+" "(" 'constraint' ")"] * !>]}
 ```
 
 #let column-def = ```

syntax/midas.typ

@@ -0,0 +1,97 @@
+#import "@preview/fervojo:0.1.1": render
+
+#let value = ```
+{[`value` <
+  [`number` 'digit' * ! <!, ["." 'digit' * !]>],
+  [`boolean` <"False", "True">],
+  [`none` "None"]
+>]}
+```
+
+#let constraint = ```
+{[`constraint` <"_", 'value'> <">", "<", ">=", "<=", "==", "!="> <"_", 'value'>]}
+```
+
+#let type-with-constraints = ```
+{[`type-with-constraints` 'identifier' <!, ["+" "(" 'constraint' ")"] * !>]}
+```
+
+#let type-property = ```
+{[`type-property` 'identifier' ":" 'type-with-constraints']}
+```
+
+#let type-body = ```
+{[`type-body` "{" <!, 'type-property'*!> "}"]}
+```
+
+#let operation-type = ```
+{[`operation-type` "<" 'type-with-constraints' ">"]}
+```
+
+#let type-statement = ```
+{[`type-statement` "type" 'identifier' "<" 'type-with-constraints'*"," ">" <!, 'type-body'>]}
+```
+
+#let operation-statement = ```
+{[`operation-statement` "op" 'operation-type' "operator" 'operation-type' "=" 'operation-type']}
+```
+
+#let constraint-statement = ```
+{[`constraint-statement` "constraint" 'identifier' "=" 'constraint']}
+```
+
+#let statement = ```
+{[`statement` <'type-statement', 'operation-statement', 'constraint-statement'>]}
+```
+
+#let rules = (
+  value,
+  constraint,
+  type-with-constraints,
+  type-property,
+  type-body,
+  operation-type,
+  type-statement,
+  operation-statement,
+  constraint-statement,
+  statement,
+)
+
+#set text(font: "Source Sans 3")
+
+= Midas type definition syntax
+
+#for rule in rules {
+  render(rule)
+}
+
+/*
+#let by-name = (
+  value: value,
+  constraint: constraint,
+  type-with-constraints: type-with-constraints,
+  type-property: type-property,
+  type-body: type-body,
+  operation-type: operation-type,
+  type-statement: type-statement,
+  operation-statement: operation-statement,
+  constraint-statement: constraint-statement,
+)
+
+#let substitute(base-rule) = {
+  let new-rule = base-rule
+  for (key, rule) in by-name.pairs() {
+    new-rule = new-rule.replace("'" + key + "'", rule.text.slice(1, -1))
+  }
+  if new-rule != base-rule {
+    new-rule = substitute(new-rule)
+  }
+  return new-rule.replace(regex("`.*?`"), "")
+}
+
+#let combined = raw(substitute(statement.text))
+
+
+#set page(flipped: true)
+#render(combined)
+*/