%YAML 1.2
---
scalar_functions:
  -
    name: "add"
    description: "Add two decimal values."
    impls:
      - args:
          - name: x
            value: decimal<P1,S1>
          - name: y
            value: decimal<P2,S2>
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        return: |-
          init_scale = max(S1,S2)
          init_prec = init_scale + max(P1 - S1, P2 - S2) + 1
          min_scale = min(init_scale, 6)
          delta = init_prec - 38
          prec = min(init_prec, 38)
          scale_after_borrow = max(init_scale - delta, min_scale)
          scale = init_prec > 38 ? scale_after_borrow : init_scale
          DECIMAL<prec, scale>
  -
    name: "subtract"
    impls:
      - args:
          - name: x
            value: decimal<P1,S1>
          - name: y
            value: decimal<P2,S2>
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        return: |-
          init_scale = max(S1,S2)
          init_prec = init_scale + max(P1 - S1, P2 - S2) + 1
          min_scale = min(init_scale, 6)
          delta = init_prec - 38
          prec = min(init_prec, 38)
          scale_after_borrow = max(init_scale - delta, min_scale)
          scale = init_prec > 38 ? scale_after_borrow : init_scale
          DECIMAL<prec, scale>
  -
    name: "multiply"
    impls:
      - args:
          - name: x
            value: decimal<P1,S1>
          - name: y
            value: decimal<P2,S2>
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        return: |-
          init_scale = S1 + S2
          init_prec = P1 + P2 + 1
          min_scale = min(init_scale, 6)
          delta = init_prec - 38
          prec = min(init_prec, 38)
          scale_after_borrow = max(init_scale - delta, min_scale)
          scale = init_prec > 38 ? scale_after_borrow : init_scale
          DECIMAL<prec, scale>
  -
    name: "divide"
    impls:
      - args:
          - name: x
            value: decimal<P1,S1>
          - name: y
            value: decimal<P2,S2>
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        return: |-
          init_scale = max(6, S1 + P2 + 1)
          init_prec = P1 - S1 + P2 + init_scale
          min_scale = min(init_scale, 6)
          delta = init_prec - 38
          prec = min(init_prec, 38)
          scale_after_borrow = max(init_scale - delta, min_scale)
          scale = init_prec > 38 ? scale_after_borrow : init_scale
          DECIMAL<prec, scale>
  -
    name: "modulus"
    impls:
      - args:
          - name: x
            value: decimal<P1,S1>
          - name: y
            value: decimal<P2,S2>
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        return: |-
          init_scale = max(S1,S2)
          init_prec = min(P1 - S1, P2 - S2) + init_scale
          min_scale = min(init_scale, 6)
          delta = init_prec - 38
          prec = min(init_prec, 38)
          scale_after_borrow = max(init_scale - delta, min_scale)
          scale = init_prec > 38 ? scale_after_borrow : init_scale
          DECIMAL<prec, scale>
aggregate_functions:
  - name: "sum"
    description: Sum a set of values.
    impls:
      - args:
          - name: x
            value: "DECIMAL<P, S>"
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        nullability: DECLARED_OUTPUT
        decomposable: MANY
        intermediate: "DECIMAL?<38,S>"
        return: "DECIMAL?<38,S>"
  - name: "avg"
    description: Average a set of values.
    impls:
      - args:
          - name: x
            value: "DECIMAL<P,S>"
        options:
          overflow:
            values: [ SILENT, SATURATE, ERROR ]
        nullability: DECLARED_OUTPUT
        decomposable: MANY
        intermediate: "STRUCT<DECIMAL<38,S>,i64>"
        return: "DECIMAL<38,S>"
  - name: "min"
    description: Min a set of values.
    impls:
      - args:
          - name: x
            value: "DECIMAL<P, S>"
        nullability: DECLARED_OUTPUT
        decomposable: MANY
        intermediate: "DECIMAL?<P, S>"
        return: "DECIMAL?<P, S>"
  - name: "max"
    description: Max a set of values.
    impls:
      - args:
          - name: x
            value: "DECIMAL<P,S>"
        nullability: DECLARED_OUTPUT
        decomposable: MANY
        intermediate: "DECIMAL?<P, S>"
        return: "DECIMAL?<P, S>"