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[Query] Inspect Strict Functions

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Generated from 'wiki-query.ts' on 2026-08-18, 14:51:36 UTC (v2.14.0), please do not edit directly.

Inspect Strict Functions Query [overview]

Determine whether functions force their arguments
This query is requested with the type inspect-strictness.
Run in the REPL: :query @inspect-strictness [(<crit>;...)] <code | file://path>

R hands arguments over as promises, so a parameter is only evaluated once something reads it. With this query you can find out which functions rely on that: a function is always strict if every call forces every one of its parameters, never strict if no call forces all of them, and conditionally strict if it depends on the path taken, on the caller, or on a function flowR could not resolve. The result carries the same verdict per parameter, keyed by the id of the parameter's name.

Please note that a read that only hands the parameter to another function does not force it by itself. Whether it is forced then depends on the function receiving it, which is resolved through the call graph. A read within a nested function definition, within a loop, or under a condition leaves the parameter conditionally strict, as does a call whose target flowR does not know.

What a built-in does with an argument is taken from what flowR states about it rather than from its name: an argument declared as quoted or as one whose presence alone matters (quote(expr), missing(x)) is never evaluated, one declared as forced (force(x)) always is, and the calls that reach an argument only on the way the run happens to take are the ones flowR hands to the processor saying so (switch picking a branch, tryCatch reaching a handler, on.exit running at exit, and the short-circuiting &&/||). A definition of your own shadowing such a name is judged by its own body instead, as R would. A parameter read only in the default of another parameter is conditionally strict, as that default is evaluated only when the argument is left out.

A generic mentions none of its arguments, so its verdict comes from the methods that S3 dispatch reaches: if they agree the answer is theirs, otherwise the parameter is conditionally strict. The object the dispatch is on is forced by the dispatch itself, which also covers standardGeneric. A NextMethod carries the question on to the methods it reaches, matched by the position the parameter is written in, and an argument travelling in ... is followed to the parameter it binds to. The method of an object flowR cannot resolve, such as obj$m(x), leaves the parameter conditionally strict:

[ { "type": "inspect-strictness" } ]

(This can be shortened to @inspect-strictness when used with the REPL command :query).

Results (prettified and summarized):

Query: inspect-strictness (5ms)
  - Function 10 (1.6-34) is conditionally strict (x: always, y: conditionally)
  - Function 19 (2.14-29) is never strict (x: always, y: never)
  - Function 28 (3.14-29) is never strict (x: never, y: always)
All queries together required ≈6 ms (1ms accuracy, total 7 ms)

Show Detailed Results as Json

The analysis required 6.8 ms (including parsing and normalization and the query) within the generation environment.

In general, the JSON contains the Ids of the nodes in question as they are present in the normalized AST or the dataflow graph of flowR. Please consult the Interface wiki page for more information on how to get those.

{
  "inspect-strictness": {
    ".meta": {
      "timing": 5
    },
    "strictness": {
      "10": {
        "strict": "maybe",
        "parameters": {
          "1": "always",
          "3": "maybe"
        }
      },
      "19": {
        "strict": "never",
        "parameters": {
          "13": "always",
          "15": "never"
        }
      },
      "28": {
        "strict": "never",
        "parameters": {
          "22": "never",
          "24": "always"
        }
      }
    }
  },
  ".meta": {
    "timing": 6
  }
}
Original Code 
f <- function(x, y) UseMethod("f")
f.default <- function(x, y) x
f.numeric <- function(x, y) y
Dataflow Graph of the R Code

The analysis required 4.6 ms (including parse and normalize, using the r-shell engine) within the generation environment. No signature database is mounted for these generated graphs, so library() calls attach no package exports; base-R names are still qualified via the generated base-package store (e.g. acf as stats::acf). We encountered no unknown side effects during the analysis.

flowchart LR
    10["`*#91;RFunctionDefinition#93;* **function**
      *1.6-34* (**id: 10**)`"]

subgraph "flow-10" [function 10]
    1["`*#91;RSymbol#93;* **x**
      *1.15* (**id: 1**, v: )`"]
    3["`*#91;RSymbol#93;* **y**
      *1.18* (**id: 3**, v: )`"]
    %% Environment of 6 [level: 1]:
    %% Built-in
    %% 1----------------------------------------
    %% 2----------------------------------------
    %%   x: {**x** (id: 1, type: Parameter, def. @2)}
    %%   y: {**y** (id: 3, type: Parameter, def. @4)}
    6[["`*#91;RString#93;* **#34;f#34;**
      *1.31-33* (**id: 6**)
    arg: (x (1), y (3))`"]]
    8[["`*#91;RFunctionCall#93;* base#58;#58;**UseMethod**
      *1.21-34* (**id: 8**)
    arg: (6, 8)`"]]
    built-in:UseMethod["`Built-In:
UseMethod`"]
    style built-in:UseMethod stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    style 6 stroke:purple,stroke-width:4px; 
    style 8 stroke:purple,stroke-width:4px; 
    style 6 stroke:purple,stroke-width:4px; 
end
   %% No edges found for 10
    0["`*#91;RSymbol#93;* **f**
      *1.1* (**id: 0**, v: 10)`"]
    11[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *1.1-34* (**id: 11**)
    arg: (0, 10)`"]]
    built-in:_-["`Built-In:
#60;#45;`"]
    style built-in:_- stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    19["`*#91;RFunctionDefinition#93;* **function**
      *2.14-29* (**id: 19**)#91;#34;s3#34;#93;`"]

subgraph "flow-19" [function 19]
    13["`*#91;RSymbol#93;* **x**
      *2.23* (**id: 13**, v: )`"]
    15["`*#91;RSymbol#93;* **y**
      *2.26* (**id: 15**, v: )`"]
    17(["`*#91;RSymbol#93;* **x**
      *2.29* (**id: 17**)`"])
end
   %% No edges found for 19
    12["`*#91;RSymbol#93;* **f.default**
      *2.1-9* (**id: 12**, v: 19)`"]
    20[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *2.1-29* (**id: 20**)
    arg: (12, 19)`"]]
    28["`*#91;RFunctionDefinition#93;* **function**
      *3.14-29* (**id: 28**)#91;#34;s3#34;#93;`"]

subgraph "flow-28" [function 28]
    22["`*#91;RSymbol#93;* **x**
      *3.23* (**id: 22**, v: )`"]
    24["`*#91;RSymbol#93;* **y**
      *3.26* (**id: 24**, v: )`"]
    26(["`*#91;RSymbol#93;* **y**
      *3.29* (**id: 26**)`"])
end
   %% No edges found for 28
    21["`*#91;RSymbol#93;* **f.numeric**
      *3.1-9* (**id: 21**, v: 28)`"]
    29[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *3.1-29* (**id: 29**)
    arg: (21, 28)`"]]
    1 -->|"def-on-call"| 22
    1 -->|"def-on-call"| 13
    3 -->|"def-on-call"| 24
    3 -->|"def-on-call"| 15
    6 -->|"arg"| 1
    6 -->|"arg"| 3
    6 -->|"calls"| 28
    6 -->|"returns"| 26
    6 -->|"calls"| 19
    6 -->|"returns"| 17
    8 -->|"arg"| 6
    8 -.->|"reads, calls"| built-in:UseMethod
    linkStyle 11 stroke:gray;
10 -.-|function| flow-10

    0 -->|"defined-by"| 10
    0 -->|"defined-by"| 11
    11 -->|"reads, arg"| 10
    11 -->|"returns, arg"| 0
    11 -.->|"reads, calls"| built-in:_-
    linkStyle 17 stroke:gray;
    13 -->|"def-by-on-call"| 1
    15 -->|"def-by-on-call"| 3
    17 -->|"reads"| 13
19 -.-|function| flow-19

    12 -->|"defined-by"| 19
    12 -->|"defined-by"| 20
    20 -->|"reads, arg"| 19
    20 -->|"returns, arg"| 12
    20 -.->|"reads, calls"| built-in:_-
    linkStyle 26 stroke:gray;
    22 -->|"def-by-on-call"| 1
    24 -->|"def-by-on-call"| 3
    26 -->|"reads"| 24
28 -.-|function| flow-28

    21 -->|"defined-by"| 28
    21 -->|"defined-by"| 29
    29 -->|"reads, arg"| 28
    29 -->|"returns, arg"| 21
    29 -.->|"reads, calls"| built-in:_-
    linkStyle 35 stroke:gray;
Loading

Using the example code f <- function(a, b, c) { print(a); if(runif(1) > .5) print(b); 42 } the following query returns the information for all identified function definitions whether they are strict:

[ { "type": "inspect-strictness" } ]

(This can be shortened to @inspect-strictness when used with the REPL command :query).

Results (prettified and summarized):

Query: inspect-strictness (5ms)
  - Function 27 (1.6-67) is never strict (a: always, b: conditionally, c: never)
All queries together required ≈5 ms (1ms accuracy, total 6 ms)

Show Detailed Results as Json

The analysis required 6.3 ms (including parsing and normalization and the query) within the generation environment.

In general, the JSON contains the Ids of the nodes in question as they are present in the normalized AST or the dataflow graph of flowR. Please consult the Interface wiki page for more information on how to get those.

{
  "inspect-strictness": {
    ".meta": {
      "timing": 5
    },
    "strictness": {
      "27": {
        "strict": "never",
        "parameters": {
          "1": "always",
          "3": "maybe",
          "5": "never"
        }
      }
    }
  },
  ".meta": {
    "timing": 5
  }
}
Original Code 
f <- function(a, b, c) { print(a); if(runif(1) > .5) print(b); 42 }
Dataflow Graph of the R Code

The analysis required 3.0 ms (including parse and normalize, using the r-shell engine) within the generation environment. No signature database is mounted for these generated graphs, so library() calls attach no package exports; base-R names are still qualified via the generated base-package store (e.g. acf as stats::acf). We encountered unknown side effects (with ids: 12 (linked), 22 (linked)) during the analysis.

flowchart LR
    27["`*#91;RFunctionDefinition#93;* **function**
      *1.6-67* (**id: 27**)`"]

subgraph "flow-27" [function 27]
    1["`*#91;RSymbol#93;* **a**
      *1.15* (**id: 1**, v: )`"]
   %% No edges found for 1
    3["`*#91;RSymbol#93;* **b**
      *1.18* (**id: 3**, v: )`"]
   %% No edges found for 3
    5["`*#91;RSymbol#93;* **c**
      *1.21* (**id: 5**, v: )`"]
   %% No edges found for 5
    10(["`*#91;RSymbol#93;* **a**
      *1.32* (**id: 10**)`"])
    12[["`*#91;RFunctionCall#93;* base#58;#58;**print**
      *1.26-33* (**id: 12**)
    arg: (10)`"]]
    built-in:print["`Built-In:
print`"]
    style built-in:print stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    14{{"`*#91;RNumber#93;* **1**
      *1.45* (**id: 14**)`"}}
   %% No edges found for 14
    16[["`*#91;RFunctionCall#93;* stats#58;#58;**runif**
      *1.39-46* (**id: 16**)
    arg: (14)`"]]
    built-in:runif["`Built-In:
runif`"]
    style built-in:runif stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    17{{"`*#91;RNumber#93;* **.5**
      *1.50-51* (**id: 17**)`"}}
   %% No edges found for 17
    18[["`*#91;RBinaryOp#93;* base#58;#58;**#62;**
      *1.39-51* (**id: 18**)
    arg: (16, 17)`"]]
    built-in:_["`Built-In:
#62;`"]
    style built-in:_ stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    20(["`*#91;RSymbol#93;* **b**
      *1.60* (**id: 20**)`"])
    22[["`*#91;RFunctionCall#93;* base#58;#58;**print**
      *1.54-61* (**id: 22**, 24+)
    arg: (20)`"]]
    24[["`*#91;RIfThenElse#93;* base#58;#58;**if**
      *1.36-61* (**id: 24**)
    arg: (18, 22, #91;empty#93;)`"]]
    built-in:if["`Built-In:
if`"]
    style built-in:if stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    25{{"`*#91;RNumber#93;* **42**
      *1.64-65* (**id: 25**)`"}}
   %% No edges found for 25
    26[["`*#91;RExpressionList#93;* base#58;#58;**#123;**
      *1.24* (**id: 26**)
    arg: (12, 24, 25)`"]]
    style 12 stroke:purple,stroke-width:4px; 
    style 22 stroke:purple,stroke-width:4px; 
    style 24 stroke:purple,stroke-width:4px; 
    style 16 stroke:purple,stroke-width:4px; 
    style 18 stroke:purple,stroke-width:4px; 
    style 25 stroke:purple,stroke-width:4px; 
    style 26 stroke:purple,stroke-width:4px; 
end
   %% No edges found for 27
    0["`*#91;RSymbol#93;* **f**
      *1.1* (**id: 0**, v: 27)`"]
    28[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *1.1-67* (**id: 28**)
    arg: (0, 27)`"]]
    built-in:_-["`Built-In:
#60;#45;`"]
    style built-in:_- stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    10 -->|"reads"| 1
    12 -->|"reads, returns, arg"| 10
    12 -.->|"reads, calls"| built-in:print
    linkStyle 2 stroke:gray;
    16 -->|"reads, arg"| 14
    16 -.->|"reads, calls"| built-in:runif
    linkStyle 4 stroke:gray;
    18 -->|"reads, arg"| 16
    18 -->|"reads, arg"| 17
    18 -.->|"reads, calls"| built-in:_
    linkStyle 7 stroke:gray;
    20 -->|"reads"| 3
    22 -->|"reads, returns, arg"| 20
    22 -.->|"reads, calls"| built-in:print
    linkStyle 10 stroke:gray;
    22 -->|"CD-True"| 24
    linkStyle 11 stroke:gray,color:gray;
    24 -->|"returns, arg"| 22
    24 -->|"reads, arg"| 18
    24 -.->|"reads, calls"| built-in:if
    linkStyle 14 stroke:gray;
    26 -->|"arg"| 12
    26 -->|"arg"| 24
    26 -->|"returns, arg"| 25
    26 -.->|"reads, calls"| built-in:_
    linkStyle 18 stroke:gray;
27 -.-|function| flow-27

    0 -->|"defined-by"| 27
    0 -->|"defined-by"| 28
    28 -->|"reads, arg"| 27
    28 -->|"returns, arg"| 0
    28 -.->|"reads, calls"| built-in:_-
    linkStyle 24 stroke:gray;
Loading

This query also supports a slicing criterion based query mode that only returns information for functions matching the given criteria:

[
  {
    "type": "inspect-strictness",
    "filter": [
      "1@function"
    ]
  }
]

(This can be shortened to @inspect-strictness (1@function) "f <- function(a, b, c) { print(a); if(runif(1) > .5) print(b); 42 }" when used with the REPL command :query).

Results (prettified and summarized):

Query: inspect-strictness (5ms)
  - Function 27 (1.6-67) is never strict (a: always, b: conditionally, c: never)
All queries together required ≈5 ms (1ms accuracy, total 5 ms)

Show Detailed Results as Json

The analysis required 4.8 ms (including parsing and normalization and the query) within the generation environment.

In general, the JSON contains the Ids of the nodes in question as they are present in the normalized AST or the dataflow graph of flowR. Please consult the Interface wiki page for more information on how to get those.

{
  "inspect-strictness": {
    ".meta": {
      "timing": 5
    },
    "strictness": {
      "27": {
        "strict": "never",
        "parameters": {
          "1": "always",
          "3": "maybe",
          "5": "never"
        }
      }
    }
  },
  ".meta": {
    "timing": 5
  }
}
Original Code 
f <- function(a, b, c) { print(a); if(runif(1) > .5) print(b); 42 }
Dataflow Graph of the R Code

The analysis required 3.8 ms (including parse and normalize, using the r-shell engine) within the generation environment. No signature database is mounted for these generated graphs, so library() calls attach no package exports; base-R names are still qualified via the generated base-package store (e.g. acf as stats::acf). We encountered unknown side effects (with ids: 12 (linked), 22 (linked)) during the analysis.

flowchart LR
    27["`*#91;RFunctionDefinition#93;* **function**
      *1.6-67* (**id: 27**)`"]

subgraph "flow-27" [function 27]
    1["`*#91;RSymbol#93;* **a**
      *1.15* (**id: 1**, v: )`"]
   %% No edges found for 1
    3["`*#91;RSymbol#93;* **b**
      *1.18* (**id: 3**, v: )`"]
   %% No edges found for 3
    5["`*#91;RSymbol#93;* **c**
      *1.21* (**id: 5**, v: )`"]
   %% No edges found for 5
    10(["`*#91;RSymbol#93;* **a**
      *1.32* (**id: 10**)`"])
    12[["`*#91;RFunctionCall#93;* base#58;#58;**print**
      *1.26-33* (**id: 12**)
    arg: (10)`"]]
    built-in:print["`Built-In:
print`"]
    style built-in:print stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    14{{"`*#91;RNumber#93;* **1**
      *1.45* (**id: 14**)`"}}
   %% No edges found for 14
    16[["`*#91;RFunctionCall#93;* stats#58;#58;**runif**
      *1.39-46* (**id: 16**)
    arg: (14)`"]]
    built-in:runif["`Built-In:
runif`"]
    style built-in:runif stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    17{{"`*#91;RNumber#93;* **.5**
      *1.50-51* (**id: 17**)`"}}
   %% No edges found for 17
    18[["`*#91;RBinaryOp#93;* base#58;#58;**#62;**
      *1.39-51* (**id: 18**)
    arg: (16, 17)`"]]
    built-in:_["`Built-In:
#62;`"]
    style built-in:_ stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    20(["`*#91;RSymbol#93;* **b**
      *1.60* (**id: 20**)`"])
    22[["`*#91;RFunctionCall#93;* base#58;#58;**print**
      *1.54-61* (**id: 22**, 24+)
    arg: (20)`"]]
    24[["`*#91;RIfThenElse#93;* base#58;#58;**if**
      *1.36-61* (**id: 24**)
    arg: (18, 22, #91;empty#93;)`"]]
    built-in:if["`Built-In:
if`"]
    style built-in:if stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    25{{"`*#91;RNumber#93;* **42**
      *1.64-65* (**id: 25**)`"}}
   %% No edges found for 25
    26[["`*#91;RExpressionList#93;* base#58;#58;**#123;**
      *1.24* (**id: 26**)
    arg: (12, 24, 25)`"]]
    style 12 stroke:purple,stroke-width:4px; 
    style 22 stroke:purple,stroke-width:4px; 
    style 24 stroke:purple,stroke-width:4px; 
    style 16 stroke:purple,stroke-width:4px; 
    style 18 stroke:purple,stroke-width:4px; 
    style 25 stroke:purple,stroke-width:4px; 
    style 26 stroke:purple,stroke-width:4px; 
end
   %% No edges found for 27
    0["`*#91;RSymbol#93;* **f**
      *1.1* (**id: 0**, v: 27)`"]
    28[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *1.1-67* (**id: 28**)
    arg: (0, 27)`"]]
    built-in:_-["`Built-In:
#60;#45;`"]
    style built-in:_- stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    10 -->|"reads"| 1
    12 -->|"reads, returns, arg"| 10
    12 -.->|"reads, calls"| built-in:print
    linkStyle 2 stroke:gray;
    16 -->|"reads, arg"| 14
    16 -.->|"reads, calls"| built-in:runif
    linkStyle 4 stroke:gray;
    18 -->|"reads, arg"| 16
    18 -->|"reads, arg"| 17
    18 -.->|"reads, calls"| built-in:_
    linkStyle 7 stroke:gray;
    20 -->|"reads"| 3
    22 -->|"reads, returns, arg"| 20
    22 -.->|"reads, calls"| built-in:print
    linkStyle 10 stroke:gray;
    22 -->|"CD-True"| 24
    linkStyle 11 stroke:gray,color:gray;
    24 -->|"returns, arg"| 22
    24 -->|"reads, arg"| 18
    24 -.->|"reads, calls"| built-in:if
    linkStyle 14 stroke:gray;
    26 -->|"arg"| 12
    26 -->|"arg"| 24
    26 -->|"returns, arg"| 25
    26 -.->|"reads, calls"| built-in:_
    linkStyle 18 stroke:gray;
27 -.-|function| flow-27

    0 -->|"defined-by"| 27
    0 -->|"defined-by"| 28
    28 -->|"reads, arg"| 27
    28 -->|"returns, arg"| 0
    28 -.->|"reads, calls"| built-in:_-
    linkStyle 24 stroke:gray;
Loading
Implementation Details

Responsible for the execution of the Inspect Strict Functions Query query is executeStrictnessQuery in ./src/queries/catalog/inspect-strictness-query/inspect-strictness-query-executor.ts.

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