E50001: not resolved

What went wrong

The compiler cannot find a variable or identifier with this name in the current scope. The name is not recognized as any declared symbol.

Worked examples

Compilable examples demonstrating this error and the correct fix:

• ek9 -q 22 (How do I declare a variable in EK9?)
• ek9 -q 17 (Where is the main function in EK9?)
• ek9 -q 3 (How do I print output to the console?)
• ek9 -q 46 (How does the Dict type work in EK9?)
• ek9 -q 33 (How do I work with regular expressions?)
• ek9 -q 1380 (How do I split my code across multiple .ek9 files in one ...)

How to fix it

1. Check spelling - EK9 is case-sensitive
2. Ensure variable is declared before use
3. Add reference statement if the name is in another MODULE
4. If the name is in another FILE of the same module, that file is not in the build - add a package.ek9 with applyStandardIncludes (see ek9 -q 1380)
5. Check variable scope (may be out of scope)

Common causes

• Typo in variable/identifier name
• Variable not declared in this scope
• Missing import/reference statement
• Declared in a sibling .ek9 file that the build does not include (same module is NOT enough - the package block decides which files are compiled)
• Using variable before declaration
• Variable declared in different scope (e.g., inner block)
• A fully qualified name 'M::X' where module M only IMPORTS X with 'references'. A qualified name reaches only what its module DEFINES; the message names where X is defined - qualify it with that module

See also

• E50001: identifier/variable not found (this error)
• E50010: TYPE not found (class/record/trait names)
• E50060: METHOD not found (method/function calls)

Examples

Every example is compiled by the EK9 compiler: the first fails exactly as captioned, the others fix it.

Fails with E50001: not resolved

#!ek9
defines module error.e50001.bad

  defines function

    greeting()
      -> customerName as String
      <- message as String?
      message: salutation + customerName

Fixed: Declare the name before you use it

#!ek9
defines module error.e50001.good

  defines function

    greeting()
      -> customerName as String
      <- message as String?
      salutation <- "Hello, "
      message: salutation + customerName

Questions and answers

These Q&A entries show E50001 and its fix:

• Q3: How do I print output to the console?
• Q17: Where is the main function in EK9?
• Q22: How do I declare a variable in EK9?
• Q46: How does the Dict type work in EK9?
• Q49: How do I define a function in EK9?
• Q96: How do operators work in EK9?
• Q97: What is the difference between classes and records in EK9?
• Q114: How do aspects work with components for AOP?
• Q118: How do I implement the builder pattern in EK9?
• Q119: What EK9 constructs are available and when should I use each?
• Q120: How do I sort a collection in EK9?
• Q123: How do I flatten nested collections and optionals in EK9?
• Q127: How does collection type inference work in EK9?
• Q140: How do I define constants in EK9?
• Q142: How do I use constants across modules in EK9?
• Q191: How do I process JSON data with stream pipelines in EK9?
• Q192: How do I modify and combine JSON objects in EK9?
• Q261: What is idiomatic EK9 code?
• Q262: How do I implement the observer pattern in EK9?
• Q265: How do I implement a fluent API in EK9?
• Q267: What are common EK9 anti-patterns to avoid?
• Q268: How does EK9 prevent common security vulnerabilities?
• Q270: How does supply chain security work in EK9?
• Q271: How do I handle secrets and environment configuration?
• Q273: How does purity create security boundaries?
• Q276: Why does AI confuse declarations and assignments in EK9?
• Q281: How do I verify AI-generated EK9 code?
• Q285: How do I handle multiple preconditions without early return?
• Q286: How do I accumulate partial results without break?
• Q289: How do I convert functions with multiple return statements to EK9?
• Q295: Can I use single-letter variable names in EK9?
• Q298: What is allow only on traits in EK9?
• Q299: How does allow only work with dispatchers in EK9?
• Q304: What is the require statement and when should I use it?
• Q310: How does EK9 enforce code quality at compile time?
• Q311: What code quality checks does the EK9 compiler perform?
• Q312: How does EK9 measure complexity?
• Q313: How does EK9 detect code smells?
• Q314: How does EK9 measure cohesion and coupling?
• Q316: How does EK9 detect discarded return values?
• Q321: How do I see the code quality report?
• Q322: How do I see how many times code was called and how long it took?
• Q323: Can AI help me improve code quality?
• Q325: What is the EK9 equivalent of Spring @Component and @Service?
• Q327: How does EK9 DI compare to Spring Boot auto-configuration?
• Q330: Does EK9 support DI scopes like singleton, prototype, and request?
• Q331: How do I test components with injected dependencies?
• Q336: How do dynamic functions solve transaction API pollution?
• Q536: How do I get the current date and time in EK9?
• Q538: How do I parse a date from a string in EK9?
• Q544: How do I measure elapsed time for benchmarking in EK9?
• Q546: What is the difference between withSameInstant() and withZone() in EK9?
• Q555: How do I construct a DateTime from individual components in EK9?
• Q556: How does Time wrapping work in EK9?
• Q563: How do pure constructors work and why use ':=?' for field assignment?
• Q564: Why must all constructors be pure if any one is pure?
• Q566: What can and cannot be called from a pure method?
• Q570: What does 'override' mean in EK9 and when is it required?
• Q605: What does 'this' mean inside a standalone function, and why can't I reach fields through it?
• Q622: How do I format an EK9 source file?
• Q623: How do I format all EK9 source files in my project?
• Q624: How do I format an EK9 file that does not parse?
• Q626: How do I integrate EK9 formatting into my development workflow?
• Q627: How do I profile an EK9 program?
• Q629: How do I read an EK9 flame graph?
• Q631: How do I benchmark two approaches in EK9?
• Q632: How does EK9 ensure variables are used only after they are defined?
• Q634: Why must I use a guard before accessing a returned value?
• Q636: How do I chain multiple guards for safe access?
• Q657: How does service URI mapping work with :/path syntax?
• Q659: Why must every service method return HTTPResponse?
• Q660: How do CRUD operators map to URIs with path parameters?
• Q684: What are the rules for valid service URI paths and method mapping?
• Q685: What must service method bodies contain and what is prohibited?
• Q728: What is the maximum nesting depth allowed in EK9 and why?
• Q766: What is the module coupling limit in EK9?
• Q963: How does the <? coalescing minimum operator work in EK9?
• Q964: How does the >? coalescing maximum operator work in EK9?
• Q968: Why does EK9 separate variable declaration from assignment?
• Q972: My variable already exists but <- creates a new one — help!
• Q974: Show me a practical EK9 example using both <- and := together.
• Q977: How do I filter a list and print the results to stdout in EK9?
• Q980: How do reject and tee work in EK9 stream pipelines?
• Q983: What are the most common EK9 compiler errors and what do they mean?
• Q986: How does EK9's := differ from Python's := walrus operator?
• Q987: What does this stream pipeline do? Trace the data flow step by step.
• Q1002: Show me the simplest possible stream pipeline that outputs to stdout in EK9.
• Q1005: In Go I use := for short variable declaration and = for assignment. How does EK9 handle this?
• Q1029: My code uses := for the first variable. Fix it with the minimum change.
• Q1033: I used := to create a list. How do I fix it?
• Q1039: When do I use <- and when do I use :=? to set a variable safely?
• Q1040: I used := to create a variable and got an error. Why?
• Q1041: I come from Python. I keep using := where I should use <-. How do I remember the difference?
• Q1042: I come from Go. How does EK9 assignment differ from Go's := and =?
• Q1050: How do the coalescing operators <?, >? work on a custom class?
• Q1054: My code has three errors. Fix them all with minimal changes.
• Q1067: What is the difference between < and <? in EK9?
• Q1092: Get the smaller of two prices, even if one might be unset.
• Q1104: Get the absolute value of -42 and the square root of 16.
• Q1120: Register a component without an aspect to show the baseline behaviour.
• Q1125: Create a dynamic function that captures a prefix variable and prepends it to input.
• Q1135: Sort a list of Item records by price and collect the sorted result.
• Q1148: Iterate from 10 down to 1 using a descending for-range.
• Q1149: Iterate from 0 to 20 with a step of 5 using for-range with by.
• Q1170: Use an enumeration value in a switch statement to select behaviour.
• Q1177: Use fully qualified enum values in a switch to map Direction to its opposite.
• Q1189: How do I compare two money amounts and find the cheaper price in EK9?
• Q1193: How do I compare screen resolutions and find the higher one in EK9?
• Q1199: Sort a list of Meeting records by date then by time using a stream pipeline.
• Q1208: Find the earlier of two delivery dates, even if one is unknown.
• Q1212: Get the lower of two sensor readings where one sensor might be offline.
• Q1213: Select the lower temperature from two weather stations.
• Q1217: Get the higher score from two optional exam results.
• Q1235: Write me a generic Formatter of type T that captures a prefix variable from the enclosing scope and uses it inside the overridden format method.
• Q1380: How do I split my code across multiple .ek9 files in one project?
• Q1381: Can I put a guard on a stream 'for' pipeline?
• Q1980: What do <-, :=? and := each do in the head of an if, switch, for, while or try?