Frontend Emission Demos
These examples show the layer between source-level View annotations and the portable View Contract checker.
Each *.source.txt file is pseudo-source: it is not parsed by tricu. It shows
the information a frontend has after parsing/elaboration.
Each matching *.emitted.tri file shows the lowered typed-program metadata that
a frontend can emit today. A successful check returns checked-exec; these demos
focus on structural Views, so they report "ok" as soon as metadata checking
succeeds. Guarded programs should run the returned checked-exec with
runChecked, as shown in demos/viewContracts.tri and by tricu check.
Successful map use
Pseudo-source:
map : Fn [Fn [Bool] String, List Bool] (List String)
f : Fn [Bool] String
xs : List Bool
partial = map f
out = partial xs
require out : List String
Run the emitted artifact:
tricu eval demos/viewContracts/frontendEmission/map-success.emitted.tri -f decode
Expected output:
"ok"
Wrong list argument
Pseudo-source:
map : Fn [Fn [Bool] String, List Bool] (List String)
f : Fn [Bool] String
xs : List String
partial = map f
out = partial xs
Run:
tricu eval demos/viewContracts/frontendEmission/map-wrong-list.emitted.tri -f decode
Expected output:
"symbol 162 expected List Bool but got List String"
Wrong filter predicate
Pseudo-source:
filter : Fn [Fn [Bool] Bool, List Bool] (List Bool)
pred : Fn [Bool] String
xs : List Bool
partial = filter pred
out = partial xs
Run:
tricu eval demos/viewContracts/frontendEmission/filter-wrong-predicate.emitted.tri -f decode
Expected output:
"symbol 181 expected Fn [Bool] Bool but got Fn [Bool] String"
Lowering shape
A frontend does not need to expose tricu syntax internally. It only needs to
emit portable typed-program nodes:
typedValue symbol view term
typedApply out callee arg term
typedRequire symbol view term
The source-level flow:
out = map f xs
lowers to curried Tree Calculus application nodes:
typedApply partial map f partialTerm
typedApply out partial xs outTerm
Function Views drive argument checking and result inference.