Language Model

Tea Script is a script language. A file begins with a declaration header, then contains statements that the compiler lowers into TSGraph semantic IR.

Program Shape

Program              ::= Declaration Statement*
Declaration          ::= IndicatorDeclaration | StrategyDeclaration
IndicatorDeclaration ::= "indicator" "(" StringLiteral ")"
StrategyDeclaration  ::= "strategy" "(" StringLiteral ")"

Library headers are reserved language-level forms and remain syntax errors until the grammar and semantic rules own them.

Statements And Expressions

Tea Script v0 supports:

• assignment statements: period = input.int(20);
• tuple assignment for tuple-returning builtins: [macd, signal, hist] = ta.macd(close, 12, 26, 9);
• expression statements for accepted effect calls;
• if statements over accepted expressions and effect forms;
• object expressions for supported option objects;
• arithmetic, comparison, boolean, ternary, call, member, and lookback expressions.

Runtime Contracts

• Source series resolve through the bound main input.
• Lookback expressions are no-lookahead reads over prior aligned rows.
• Stateful TA functions own prefix state and warmup through TSGraph lowering.
• input.* declarations produce parameter descriptors and compile-time override points.
• output(...) defines persisted output fields.
• plot(...), draw.*, log.*, alert.*, and strategy calls are effects in semantic IR.
• Strategy order effects are valid only inside strategy(...) scripts.

Compatibility Boundary

Tea Script is Pine-inspired, but Pine compatibility is not the durable contract. Compatibility is useful when it helps users and agents migrate scripts. The actual contract is the grammar, semantic rules, diagnostics, capability manifest, and TSGraph lowering behavior owned by the compiler.