feat(snowflake): T1.2 data types — TypeName struct + parseDataType#39
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feat(snowflake): T1.2 data types — TypeName struct + parseDataType#39
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Single TypeName struct with TypeKind enum (22 values) covering every Snowflake data type from the legacy grammar's data_type rule. Numeric params via []int slice, recursive ElementType for ARRAY/VECTOR, and VectorDim for VECTOR(type, dim). Requires small F2 scope creep: 3 new keyword constants (kwTIMESTAMP_LTZ/NTZ/TZ) + 6 keyword map entries (with/without underscore aliases). Multi-word types (DOUBLE PRECISION, CHAR VARYING, NCHAR VARYING) handled via parser lookahead, not F2 changes. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
6-task plan: F2 timestamp variant keywords (3 constants + 6 map entries), TypeKind enum (22 values) + TypeName struct in ast, AST unit tests, parseDataType dispatch (all type forms from legacy grammar), parser tests (16 categories), acceptance sweep. Handles multi-word types (DOUBLE PRECISION, CHAR/NCHAR VARYING) via parser lookahead, ARRAY(element_type) via recursive parse, and VECTOR(type, dim) via restricted element-type rule. Walker regen produces a real *TypeName case with ElementType child walk. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Second Tier 1 node. Adds data type parsing covering every form from the
legacy SnowflakeParser.g4 data_type rule.
AST types (snowflake/ast):
type TypeKind int // 22 values: TypeInt through TypeVector
type TypeName struct {
Kind TypeKind
Name string // source text for round-tripping
Params []int // numeric params: [precision] or [precision, scale]
ElementType *TypeName // ARRAY element / VECTOR element type
VectorDim int // VECTOR dimensions; -1 for non-VECTOR
Loc Loc
}
TypeName is a Node (T_TypeName tag). The walker descends into
ElementType when non-nil (verified by TestTypeName_WalkerVisitsElementType).
Parser helpers (snowflake/parser/datatypes.go):
parseDataType() — full dispatch: 30+ keyword cases
parseOptionalTypeParams()— optional (n) or (n, m)
parseTimestampType() — shared handler for TIMESTAMP variants
parseVectorElementType() — restricted to INT/INTEGER/FLOAT/FLOAT4/FLOAT8
ParseDataType(string) — freestanding exported helper
Multi-word types (DOUBLE PRECISION, CHAR VARYING, NCHAR VARYING) are
fused via parser lookahead — F2 emits them as separate tokens (kwDOUBLE
+ tokIdent("PRECISION")), the parser peeks and combines.
F2 keyword additions (scope creep, 3 constants + 6 map entries):
kwTIMESTAMP_LTZ, kwTIMESTAMP_NTZ, kwTIMESTAMP_TZ
Both underscore and no-underscore forms in keywordMap
(TIMESTAMP_LTZ and TIMESTAMPLTZ both accepted)
Tests: 25 AST subtests (TypeKind.String, Tag, walker traversal) +
60+ parser subtests (all integer types, NUMBER with params, float
aliases, DOUBLE PRECISION, CHAR/NCHAR VARYING, all string types,
binary, timestamp variants incl. no-underscore forms, TIME/DATETIME
with precision, BOOLEAN, semi-structured, ARRAY untyped/typed/nested,
VECTOR, error cases, freestanding helper, Loc spanning).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
Second Tier 1 node of the snowflake parser migration (BYT-9000): data type parsing covering every form from the legacy
data_typegrammar rule. AddsTypeNameNode struct withTypeKindenum (22 values) tosnowflake/ast, plusparseDataType()parser helper tosnowflake/parser.Depends on T1.1 identifiers (PR #22, merged). Unblocks T1.3 (expressions — needs type parsing for CAST/TRY_CAST and
::operator).Design highlights
TypeNamestruct withKind TypeKindenum for fast dispatch +Name stringfor round-tripping. Covers INT through VECTOR with 22 classified categories. No per-type-family struct bloat.Params []intfor numeric parameters (NUMBER(38,0), VARCHAR(100), TIME(9)). Nil = no params; zero IS a valid value (TIME(0)).ElementType *TypeNamefor recursive ARRAY and VECTOR element types. Walker descends into it.Test plan
snowflake/ast/andsnowflake/parser/🤖 Generated with Claude Code