016 subflow impure

✓ Passing This code compiles and runs correctly.

Code

// Test: Subflow calling unmarked (impure) proc should be transitively impure
// Unmarked proc → Subflow calls it → Subflow should be transitively IMPURE

const std = @import("std");

// Impure operation (unmarked, so defaults to impure)
~event log { message: []const u8 }

~proc log|zig {
    std.debug.print("LOG: {s}\n", .{message});
}

// Main entry using subflow
~event main {}

// Subflow that calls impure event - should be transitively IMPURE
~log(message: "Hello")

input.kz

Actual

LOG: Hello

Test Configuration

MUST_RUN

Post-validation Script:

#!/bin/bash
# Verify: Subflow calling impure proc should be transitively IMPURE

if [ ! -f "backend.zig" ]; then
    echo "✗ backend.zig not found"
    exit 1
fi

# AST literal moved from backend.zig to program_ast.zig (split landed 2026-05-20).
# Concatenate both so grep -n / sed -n by line number still work.
cat backend.zig program_ast.zig 2>/dev/null > _combined_emit.zig

# Check log proc - should be IMPURE (not marked ~[pure])
PROC_LINE=$(grep -n 'proc_decl = ProcDecl' _combined_emit.zig | while read line; do
    linenum=$(echo "$line" | cut -d: -f1)
    # Check if "log" appears in next 5 lines
    if sed -n "$((linenum)),$((linenum + 5))p" _combined_emit.zig | grep -q '"log"'; then
        echo "$linenum"
        break
    fi
done)

if [ -z "$PROC_LINE" ]; then
    echo "✗ Could not find log proc"
    exit 1
fi

# The ProcDecl block now spans more lines (body is a Source literal: text +
# location + scope + phantom_type). Bound the block at its own `.module =` field
# rather than a fixed window — robust to body length, and won't bleed into a
# neighbouring proc (which would falsely match is_pure on negative tests).
PROC_END=$(awk -v s="$PROC_LINE" 'NR>s && /\.module = /{print NR; exit}' _combined_emit.zig)
PROC=$(sed -n "$((PROC_LINE)),$((PROC_END))p" _combined_emit.zig)

if echo "$PROC" | grep -q 'is_pure = false'; then
    echo "✓ log proc: is_pure = false (unmarked, defaults to impure)"
else
    echo "✗ FAIL: log should be is_pure = false (no ~[pure] annotation)"
    exit 1
fi

if echo "$PROC" | grep -q 'is_transitively_pure = false'; then
    echo "✓ log proc: is_transitively_pure = false"
else
    echo "✗ FAIL: log should be is_transitively_pure = false"
    exit 1
fi

# Check the top-level subflow - should be transitively IMPURE
FLOW_LINE=$(grep -n '\.flow = Flow{' _combined_emit.zig | while read line; do
    linenum=$(echo "$line" | cut -d: -f1)
    # Check if "log" appears in next 10 lines
    if sed -n "$((linenum)),$((linenum + 40))p" _combined_emit.zig | grep -q '"log"'; then
        echo "$linenum"
        break
    fi
done)

if [ -z "$FLOW_LINE" ]; then
    echo "✗ Could not find Flow calling log"
    exit 1
fi

FLOW=$(sed -n "${FLOW_LINE},$((FLOW_LINE + 50))p" _combined_emit.zig)

# Flows are always locally pure
if echo "$FLOW" | grep -q '.is_pure = true'; then
    echo "✓ subflow: is_pure = true (flows are always locally pure)"
else
    echo "✗ FAIL: subflow should be is_pure = true"
    exit 1
fi

# Subflow calls impure event, should be transitively IMPURE
if echo "$FLOW" | grep -q '.is_transitively_pure = false'; then
    echo "✓ subflow: is_transitively_pure = false (calls impure log)"
else
    echo "✗ FAIL: subflow should be is_transitively_pure = FALSE"
    echo "  It calls log (impure) - should NOT propagate transitive purity"
    exit 1
fi

echo ""
echo "✓ Subflow correctly marked transitively impure when calling impure proc"

exit 0

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