Skip to content

[Query] Inspect Exceptions of Functions

Jump to bottom
github-actions[bot] edited this page Jul 21, 2026 · 1 revision

This document was generated from 'src/documentation/wiki-query.ts' on 2026-07-20, 17:48:26 UTC presenting an overview of flowR's query API (v2.12.3). Please do not edit this file/wiki page directly.

Inspect Exceptions of Functions Query [overview]

Determine whether functions throw exceptions (known to flowR)
This query is requested with the type inspect-exception.
Run in the REPL: :query @inspect-exception [(<crit>;...)] <code | file://path>

With this query you can identify which functions in the code throw exceptions (known to flowR).

Using the following example code:

mayFail <- function(x) {
  if(x < 0) stop("Negative value!")
  else sqrt(x)
}
safeFail <- function(x) {
  tryCatch(
    mayFail(x),
    error = function(e) { NA }
  )
}

the following query returns the information for all identified function definitions whether they throw exceptions:

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

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

Results (prettified and summarized):

Query: inspect-exception (10ms)
  - Function 20 (1.12-4.1) throws exceptions:
      - Exception maybe thrown at id 11 "stop" (2.13-35, cds: true:2.3-3.14)
  - Function 40 (8.13-30) does not throw exceptions.
  - Function 44 (5.13-10.1) throws exceptions:
      - Exception maybe thrown at id 11 "stop" (2.13-35, cds: true:2.3-3.14)
All queries together required ≈10 ms (1ms accuracy, total 12 ms)

Show Detailed Results as Json

The analysis required 11.6 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-exception": {
    ".meta": {
      "timing": 10
    },
    "exceptions": {
      "20": [
        {
          "id": 11,
          "cds": [
            {
              "id": 18,
              "when": true
            }
          ]
        }
      ],
      "40": [],
      "44": [
        {
          "id": 11,
          "cds": [
            {
              "id": 18,
              "when": true
            }
          ]
        }
      ]
    }
  },
  ".meta": {
    "timing": 10
  }
}
Original Code 
mayFail <- function(x) {
  if(x < 0) stop("Negative value!")
  else sqrt(x)
}
safeFail <- function(x) {
  tryCatch(
    mayFail(x),
    error = function(e) { NA }
  )
}
Dataflow Graph of the R Code

The analysis required 6.9 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
    20["`*#91;RFunctionDefinition#93;* **function**
      *1.12-4.1* (**id: 20**)`"]

subgraph "flow-20" [function 20]
    1["`*#91;RSymbol#93;* **x**
      *1.21* (**id: 1**, v: )`"]
    5(["`*#91;RSymbol#93;* **x**
      *2.6* (**id: 5**)`"])
    6{{"`*#91;RNumber#93;* **0**
      *2.10* (**id: 6**)`"}}
   %% No edges found for 6
    7[["`*#91;RBinaryOp#93;* base#58;#58;**#60;**
      *2.6-10* (**id: 7**)
    arg: (5, 6)`"]]
    built-in:_["`Built-In:
#60;`"]
    style built-in:_ stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    9{{"`*#91;RString#93;* **#34;Negative value!#34;**
      *2.18-34* (**id: 9**)`"}}
   %% No edges found for 9
    11[["`*#91;RFunctionCall#93;* base#58;#58;**stop**
      *2.13-35* (**id: 11**, 18+)
    arg: (9)`"]]
    built-in:stop["`Built-In:
stop`"]
    style built-in:stop stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    14(["`*#91;RSymbol#93;* **x**
      *3.13* (**id: 14**)`"])
    16[["`*#91;RFunctionCall#93;* base#58;#58;**sqrt**
      *3.8-14* (**id: 16**, 18-)
    arg: (14)`"]]
    built-in:sqrt["`Built-In:
sqrt`"]
    style built-in:sqrt stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    18[["`*#91;RIfThenElse#93;* base#58;#58;**if**
      *2.3-3.14* (**id: 18**)
    arg: (7, 11, 16)`"]]
    built-in:if["`Built-In:
if`"]
    style built-in:if stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    19[["`*#91;RExpressionList#93;* base#58;#58;**#123;**
      *1.24* (**id: 19**)
    arg: (18)`"]]
end
   %% No edges found for 20
    0["`*#91;RSymbol#93;* **mayFail**
      *1.1-7* (**id: 0**, v: 20)`"]
    21[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *1.1-4.1* (**id: 21**)
    arg: (0, 20)`"]]
    built-in:_-["`Built-In:
#60;#45;`"]
    style built-in:_- stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    44["`*#91;RFunctionDefinition#93;* **function**
      *5.13-10.1* (**id: 44**)`"]

subgraph "flow-44" [function 44]
    23["`*#91;RSymbol#93;* **x**
      *5.22* (**id: 23**, v: )`"]
   %% No edges found for 23
    29(["`*#91;RSymbol#93;* **x**
      *7.13* (**id: 29**)`"])
    %% Environment of 31 [level: 1]:
    %% Built-in
    %% 1----------------------------------------
    %% 2----------------------------------------
    %%   x: {**x** (id: 23, type: Parameter, def. @24)}
    31[["`*#91;RFunctionCall#93;* **mayFail**
      *7.5-14* (**id: 31**)
    arg: (29)`"]]
    %% Environment of 40 [level: 1]:
    %% Built-in
    %% 1----------------------------------------
    %% 2----------------------------------------
    40["`*#91;RFunctionDefinition#93;* **function**
      *8.13-30* (**id: 40**)`"]

subgraph "flow-40" [function 40]
    34["`*#91;RSymbol#93;* **e**
      *8.22* (**id: 34**, v: )`"]
   %% No edges found for 34
    38{{"`*#91;RSymbol#93;* **NA**
      *8.27-28* (**id: 38**)`"}}
   %% No edges found for 38
    39[["`*#91;RExpressionList#93;* base#58;#58;**#123;**
      *8.25* (**id: 39**)
    arg: (38)`"]]
    built-in:_["`Built-In:
#123;`"]
    style built-in:_ stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    style 38 stroke:purple,stroke-width:4px; 
    style 39 stroke:purple,stroke-width:4px; 
end
   %% No edges found for 40
    41(["`*#91;RArgument#93;* **error**
      *8.5-9* (**id: 41**)`"])
    42[["`*#91;RFunctionCall#93;* base#58;#58;**tryCatch**
      *6.3-9.3* (**id: 42**)
    arg: (31, error (41))`"]]
    built-in:tryCatch["`Built-In:
tryCatch`"]
    style built-in:tryCatch stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    43[["`*#91;RExpressionList#93;* base#58;#58;**#123;**
      *5.25* (**id: 43**)
    arg: (42)`"]]
    built-in:_["`Built-In:
#123;`"]
    style built-in:_ stroke:gray,fill:gray,stroke-width:2px,opacity:.8;
    style 31 stroke:purple,stroke-width:4px; 
    style 42 stroke:purple,stroke-width:4px; 
    style 43 stroke:purple,stroke-width:4px; 
end
   %% No edges found for 44
    22["`*#91;RSymbol#93;* **safeFail**
      *5.1-8* (**id: 22**, v: 44)`"]
    45[["`*#91;RBinaryOp#93;* base#58;#58;**#60;#45;**
      *5.1-10.1* (**id: 45**)
    arg: (22, 44)`"]]
    1 -->|"def-by-on-call"| 29
    5 -->|"reads"| 1
    7 -->|"reads, arg"| 5
    7 -->|"reads, arg"| 6
    7 -.->|"reads, calls"| built-in:_
    linkStyle 4 stroke:gray;
    11 -->|"arg"| 9
    11 -.->|"reads, calls"| built-in:stop
    linkStyle 6 stroke:gray;
    11 -->|"CD-True"| 18
    linkStyle 7 stroke:gray,color:gray;
    14 -->|"reads"| 1
    16 -->|"reads, arg"| 14
    16 -.->|"reads, calls"| built-in:sqrt
    linkStyle 10 stroke:gray;
    16 -->|"CD-False"| 18
    linkStyle 11 stroke:gray,color:gray;
    18 -->|"returns, arg"| 11
    18 -->|"returns, arg"| 16
    18 -->|"reads, arg"| 7
    18 -.->|"reads, calls"| built-in:if
    linkStyle 15 stroke:gray;
    19 -->|"returns, arg"| 18
    19 -.->|"reads, calls"| built-in:_
    linkStyle 17 stroke:gray;
20 -.-|function| flow-20

    0 -->|"defined-by"| 20
    0 -->|"defined-by"| 21
    21 -->|"reads, arg"| 20
    21 -->|"returns, arg"| 0
    21 -.->|"reads, calls"| built-in:_-
    linkStyle 23 stroke:gray;
    29 -->|"reads"| 23
    29 -->|"def-on-call"| 1
    31 -->|"reads, arg"| 29
    31 -->|"calls"| 20
    31 -->|"returns"| 11
    31 -->|"returns"| 18
    39 -->|"returns, arg"| 38
    39 -.->|"reads, calls"| built-in:_
    linkStyle 1 stroke:gray;
40 -.-|function| flow-40

    41 -->|"reads, calls"| 40
    42 -->|"returns, arg"| 31
    42 -->|"reads, calls, arg"| 41
    42 -->|"returns"| 38
    42 -.->|"reads, calls"| built-in:tryCatch
    linkStyle 13 stroke:gray;
    43 -->|"returns, arg"| 42
    43 -.->|"reads, calls"| built-in:_
    linkStyle 15 stroke:gray;
44 -.-|function| flow-44

    22 -->|"defined-by"| 44
    22 -->|"defined-by"| 45
    45 -->|"reads, arg"| 44
    45 -->|"returns, arg"| 22
    45 -.->|"reads, calls"| built-in:_-
    linkStyle 45 stroke:gray;
Loading
Implementation Details

Responsible for the execution of the Inspect Exceptions of Functions Query query is executeExceptionQuery in ./src/queries/catalog/inspect-exceptions-query/inspect-exception-query-executor.ts.

Currently maintained by Florian Sihler and Oliver Gerstl at Ulm University
Email | GitHub | Penguins | Portfolio

💮 flowR Home

Clone this wiki locally