### Compilation failed:

error: 6: 'main' parameters must be (float2, (vec4|float4|half4)?)
half4 main() { return half4(1); }
^^^^^^^^^^^^
error: 7: 'main' parameters must be (float2, (vec4|float4|half4)?)
half4 main(half4 color) { return color; }
^^^^^^^^^^^^^^^^^^^^^^^
error: 7: unknown identifier 'color'
half4 main(half4 color) { return color; }
                                 ^^^^^
error: 8: 'main' parameters must be (float2, (vec4|float4|half4)?)
half4 main(float2 xy, half4 color, half4 bonusColor) { return color; }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: 8: unknown identifier 'color'
half4 main(float2 xy, half4 color, half4 bonusColor) { return color; }
                                                              ^^^^^
error: 9: 'main' parameters must be (float2, (vec4|float4|half4)?)
half4 main(half4 outOfOrderColor, float2 outOfOrderXy) { return color; }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: 9: unknown identifier 'color'
half4 main(half4 outOfOrderColor, float2 outOfOrderXy) { return color; }
                                                                ^^^^^
7 errors