Qingchu (清楚) is a programming language built around one principle: code should read like human speech and mathematical notation. Speech-like keywords, math syntax, typed bindings, and context markers — readable at a glance.
!! A simple Qingchu program !! let name = Bob name ts string print Hello name_string . math let price = 10 . math let quantity = 5 . math let total = price * quantity . math print total .
Every construct in Qingchu exists to make code clearer at a glance.
Qingchu uses words and math symbols — not programmer punctuation.
print, ask, when, define are
speech-like keywords; >, +, *, =
are plain math. A . ends a statement, like a sentence.
Every binding has a type, visible at the point of use. A binding is
referenced as name_type — so name_string,
count_number, flag_boolean. The type is part of the name.
math and string drop the type suffix so code reads
naturally. Inside math, total means total_number;
inside string, name means name_string.
Mark a binding constant and it can't be reassigned. To change an
existing binding, use new — an explicit, readable reassignment.
Branch with if / else, loop with when — loops read like
conditions ("when i < 3, print…"), and indentation opens and closes blocks.
Define functions with define … as … and return values with
calculate. Parsing is complete; execution is on the roadmap.
清楚 (qīngchu) means clear, distinct, easy to understand. That's the goal.
No cryptic punctuation. Statements end with a period, blocks are indented, and types travel with names — you can read Qingchu out loud.
name_string tells you exactly what's in the box. Constants are
locked with constant, and reassignment is always explicit with new.
Every error says what went wrong, on which line, in which statement — in plain English, not stack-trace soup.
Requires Java 17 or higher. Compile the interpreter, then run a file — or open the REPL.
Build the Java sources from the repo:
Point the interpreter at any .qc program:
Run with no arguments for an interactive session:
Twelve keywords, three types, two context markers. Hover to explore.
v0.1.0 — core language complete. Here's what works today and what's next.
let declarations with ts type blocks, math /
string context markers, print output, ask input,
new reassignment, if / else branching, when loops,
the constant modifier, comments (!! and !!!),
escapes, and readable errors with line numbers and statement context.
Parsing for define and calculate already works; execution is pending.
Collection types to round out the type system beyond number, string, and boolean.
Embed LaTeX, Python, Java, HTML, and CSS directly — plus LaTeX ↔ Unicode conversion.
Rounding helpers, string functions, and more — shipped with the interpreter.
Text → tokens → AST → run. Four packages, one Java entry point.
qingchu/ ├── src/main/java/qingchu/ │ ├── Main.java — entry point │ ├── lexer/ — text → tokens │ ├── error/ — error types │ ├── parse/ — tokens → AST │ └── runtime/ — runs the AST ├── examples/ — sample .qc programs ├── docs/ — website and documentation └── README.md
The lexer turns raw text into tokens (keywords, operators, terminators). The parser builds an AST from indentation-delimited statements. The runtime walks the tree with scopes, typed bindings, and values — reporting every failure as a readable one-line error.
Written in plain Java 17, no dependencies, tested with JUnit across the lexer, parser, and interpreter.
See it in action清楚 (qīngchu) means clear, distinct, easy to understand. That's the goal: a language where the code is clear at a glance.
Because you almost never have to write it twice. Bindings are referenced as
name_type (name_string, count_number,
flag_boolean) so the type is visible at every point of use. When that
gets noisy, the math and string context markers drop the
suffix — inside math, total just means total_number.
A lone . ends a statement, like a full stop at the end of a sentence.
Blocks are opened and closed by indentation — no braces, no end keyword.
Use \ to escape characters like \., \_, or \\.
Specific and readable, always in the same shape:
error <what went wrong> on line <N>(<which statement>) —
for example error cannot reassign constant on line 12(new statement).
Yes — clone the repo, compile with Java 17+, and run .qc files or the
REPL. The core language (declarations, types, context markers, printing, input,
branching, loops, constants, comments, escapes) is complete in v0.1.0. Function
calling, lists/maps, and the standard library are planned.
Qingchu is open source under the MIT license. This project page is part of innovationearthprojects.org — head back there to reach the team and the rest of the project family.
Clone it, compile it, and say print Hello World . — it takes 2 minutes.